Mitochondrial DNA common deletion is not associated with thyroid, breast and colorectal tumors in Turkish patients

Recently, efforts have been focused on mitochondrial DNA changes and their relation to human cancers. Among them, a 4977 bp deletion of mitochondrial DNA, named "common deletion", has been investigated in several types of tumors, with inconsistent results. In this study, we investigated the presence of the common deletion in tissues from 25 breast, 25 colorectal and 50 thyroid tumors and in the adjacent healthy tissues from Turkish patients. Samples from healthy volunteers were also evaluated for comparison. Two PCR-based methods were used for the detection of the common deletion. First, two pairs of primers were used to amplify wild-type and deleted mtDNA. Then, a highly sensitive nested-PCR was performed, to determine low amounts of deleted genomes. By the first method, wild-type mtDNAs were observed in all samples, but a deletion was observed in only six thyroid samples, by using the nested-PCR method. In conclusion, the mitochondrial common deletion was very rare in our study group and did not appear to be not related with cancer.     

A SGLT2 inhibitor dapagliflozin suppresses prolonged ventricular-repolarization through augmentation of mitochondrial function in insulin-resistant metabolic syndrome rats

Background

Metabolic syndrome (MetS) is a prevalent risk factor for cardiac dysfunction. Although SGLT2-inhibitors have important cardioprotective effects in hyperglycemia, their underlying mechanisms are complex and not completely understood. Therefore, we examined mechanisms of a SGLT2-inhibitor dapagliflozin (DAPA)-related cardioprotection in overweight insulin-resistant MetS-rats comparison with insulin (INSU), behind its glucose-lowering effect.

Methods

A 28-week high-carbohydrate diet-induced MetS-rats received DAPA (5 mg/kg), INSU (0.15 mg/kg) or vehicle for 2 weeks. To validate MetS-induction, we monitored all animals weekly by measuring body weight, blood glucose and HOMO-IR index, electrocardiograms, heart rate, systolic and diastolic pressures.

Results

DAPA-treatment of MetS-rats significantly augmented the increased blood pressure, prolonged Q–R interval, and low heart rate with depressed left ventricular function and relaxation of the aorta. Prolonged-action potentials were preserved with DAPA-treatment, more prominently than INSU-treatment, at most, through the augmentation in depressed voltage-gated K⁺-channel currents. DAPA, more prominently than INSU-treatment, preserved the depolarized mitochondrial membrane potential, and altered mitochondrial protein levels such as Mfn-1, Mfn-2, and Fis-1 as well as provided significant augmentation in cytosolic Ca²⁺-homeostasis. Furthermore, DAPA also induced significant augmentation in voltage-gated Na⁺-currents and intracellular pH, and the cellular levels of increased oxidative stress, protein-thiol oxidation and ADP/ATP ratio in cardiomyocytes from MetS rats. Moreover, DAPA-treatment normalized the increases in the mRNA level of SGLT2 in MetS-rat heart.

Conclusions

Overall, our data provided a new insight into DAPA-associated cardioprotection in MetS rats, including suppression of prolonged ventricular-repolarization through augmentation of mitochondrial function and oxidative stress followed by improvement of fusion–fission proteins, out of its glucose-lowering effect.

     

Mutation of active site residues Asn67 to Ile, Gln92 to Val and Leu204 to Ser in human carbonic anhydrase II: influences on the catalytic activity and affinity for inhibitors

Site-directed mutagenesis has been used to change three amino acid residues involved in the binding of inhibitors (Asn67Ile; Gln92Val and Leu204Ser) within the active site of human carbonic anhydrase (CA, EC 4.2.1.1) II (hCA II). Residues 67, 92 and 204 were changed from hydrophobic to hydrophilic ones, and vice versa. The Asn67Ile and Leu204Ser mutants showed similar k(cat)/K(M) values compared to the wild type (wt) enzyme, whereas the Gln92Val mutant was around 30% less active as a catalyst for CO(2) hydration to bicarbonate compared to the wt protein. Affinity for sulfonamides/sulfamates was decreased in all three mutants compared to wt hCA II. The effect was stronger for the Asn67Ile mutant (the closest residue to the zinc ion), followed by the Gln92Val mutant (residue situated in the middle of the active site) and weakest for the Leu204Ser mutant, an amino acid situated far away from the catalytic metal ion, at the entrance of the cavity. This study shows that small perturbations within the active site architecture have influences on the catalytic efficiency but dramatically change affinity for inhibitors among the CA enzymes, especially when the mutated amino acid residues are nearby the catalytic metal ion.     

DNA repair XRCC1 Arg399Gln polymorphism is associated with the risk of development of end-stage renal disease

Patients with end-stage renal disease (ESRD) display enhanced genomic damage. DNA repair gene polymorphisms may affect DNA repair capacity and modulate susceptibility to ESRD. In this study, we aimed to determine the frequency of polymorphisms in two DNA repair enzyme genes, Xeroderma pigmentosum complementation group D (XPD) and X-ray cross-complementing group 1 (XRCC1), in patients with ESRD and to evaluate their association with ESRD development. By using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP), we genotyped four single nucleotide polymorphisms (SNPs) in XPD codons 312 and 751 and XRCC1 codons 194 and 399 in 136 dialysis patients (71 patients undergoing hemodialysis and 65 subjected to peritoneal dialysis) and 147 healthy controls. Patients having XRCC1 399 Arg/Gln (OR:1.98; 95% CI: 1.21–3.25, P = 0.007) or XRCC1-399 Gln/Gln (OR: 3.95; 95% CI: 1.45–10.76, P = 0.005) genotype had a significantly higher risk of ESRD than those with XRCC1 399 Arg/Arg genotype. We also found a significantly higher frequency of the XRCC1 399Gln allele in patients with ESRD than in controls, with OR = 2.03 (95% CI = 1.08–3.81, P = 0.03). We further investigated the potential combined effect of these DNA repair variants on the risk of ESRD development. It was found that combination of the Arg/Gln or Gln/Gln genotypes of XRCC1 Arg399Gln polymorphism with the two possible genotypes of XPD-Asp312Asn or with the Lys/Gln or Gln/Gln genotypes of XPD Lys751Gln was significantly associated with the development of ESRD. This is the first report showing an association between DNA repair gene polymorphisms and ESRD development, and suggests that XRCC1 Arg399Gln polymorphism may confer increased risk for the development of the disease. Further larger studies should be conducted to confirm these results.     

GC/MS Profiling,In Vitro and In Silico Pharmacological Screening and Principal Component Analysis of Essential Oils from Three Exotic and Two Endemic Plants from Mauritius

The chemical and pharmacological profiles of essential oils (EOs) hydrodistilled in yields of 0.03–0.77 % (w/w) from three exotic (Cinnamomum camphora, Petroselinum crispum, and Syzygium samarangense) and two endemic (Pittosporum senacia subsp. senacia and Syzygium coriaceum) medicinal plants were studied. GC-MS/GC-FID analysis of the EOs identified the most dominant components to be myristicin (40.3 %), myrcene (62.2 %), 1,8-cineole (54.0 %), β-pinene (21.3 %) and (E)-β-ocimene (24.4 %) in P. crispum, P. senacia and C. camphora, S. samarangense and S. coriaceum EOs, respectively. All EOs were found to possess anti-amylase (0.70–1.50 mM ACAE/g EO) and anti-tyrosinase (109.35–158.23 mg KAE/g) properties, whereas no glucosidase inhibition was displayed. Only Syzygium EOs acted as dual inhibitors of both acetyl- and butyryl-cholinesterases, while P. senacia and C. camphora EOs inhibited acetylcholinesterase selectively and P. crispum EO was inactive (AChE: 4.64–4.96 mg GALAE/g; BChE: 5.96 and 7.10 mg GALAE/g). Molecular docking revealed 1,8-cineole to present the best binding affinities with butyrylcholinesterase, amylase and tyrosinase, while both myristicin and β-pinene with acetylcholinesterase and finally β-pinene with glucosidase. In vitro antioxidant potency was also demonstrated in different assays (DPPH: 13.52–53.91 mg TE/g, ABTS: 5.49–75.62 mg TE/g; CUPRAC: 45.38–243.21 mg TE/g, FRAP: 42.49–110.64 mg TE/g; and phosphomolybdenum assay: 82.61–160.93 mM TE/g). Principal component analysis revealed the EOs to differ greatly in their bioactivities due to their chemodiversity. This study has unveiled some interesting preliminary pharmacological profiles of the EOs that could be explored for their potential applications as phytotherapeutics.     

Engineering chromatin states: Chemical and synthetic biology approaches to investigate histone modification function

Patterns of histone post-translational modifications (PTMs) and DNA modifications establish a landscape of chromatin states with regulatory impact on gene expression, cell differentiation and development. These diverse modifications are read out by effector protein complexes, which ultimately determine their functional outcome by modulating the activity state of underlying genes. From genome-wide studies employing high-throughput ChIP-Seq methods as well as proteomic mass spectrometry studies, a large number of PTMs are known and their coexistence patterns and associations with genomic regions have been mapped in a large number of different cell types. Conversely, the molecular interplay between chromatin effector proteins and modified chromatin regions as well as their resulting biological output is less well understood on a molecular level. Within the last decade a host of chemical approaches has been developed with the goal to produce synthetic chromatin with a defined arrangement of PTMs. These methods now permit systematic functional studies of individual histone and DNA modifications, and additionally provide a discovery platform to identify further interacting nuclear proteins. Complementary chemical- and synthetic-biology methods have emerged to directly observe and modulate the modification landscape in living cells and to readily probe the effect of altered PTM patterns on biological processes. Herein, we review current methodologies allowing chemical and synthetic biological engineering of distinct chromatin states in vitro and in vivo with the aim of obtaining a molecular understanding of histone and DNA modification function. This article is part of a Special Issue entitled: Molecular mechanisms of histone modification function.     

Macrobenthic assemblages of newly introduced <Emphasis Type="Italic">Caulerpa taxifolia</Emphasis> from the Eastern Mediterranean coast of Turkey

Caulerpa taxifolia is one of the most important and best-studied alien species in the Mediterranean Sea. The present study reveals the macrobenthic assemblages associated with C. taxifolia from the region. We found 26 species from Polychaeta, 31 species from Crustacea, 22 species from Mollusca and 5 species from Echinodermata. In conclusion, C. taxifolia in İskenderun Bay can be considered an ecosystem engineer that modifies local habitats and also enhances biodiversity.     

Cytologic findings in pap smears with Actinomyces-like organisms

OBJECTIVE: To detect whether there is a relationship between the presence ofActinomyces-like organisms (ALOs) and cytologic findings. STUDY DESIGN: Papanicolaou-stained smears from 2290 women were examined cytologically. Nineteen (0.83%) of the 2290 were diagnosed with ALOs and became the study group. Patients without infectious agents (n=1792) were the control group. Statistical analyses were conducted with the chi2 test using the SPSS program (Chicago, Illinois, U.S.A.). RESULTS: The study and control groups were compared statistically. There was a significant correlation between the presence of ALOs and other cytologic findings, such as Trichomonas vaginalis, cocci, pseudoeosinophilia, endocervical cells, superficial cells, lactobacilli and polymorphonuclear leukocytes (p < 0.05), but there was no statistically significant difference between the presence of ALOs and metaplastic cells, parabasal cells or nuclear changes (p > 0. 05). CONCLUSION: ALOs in cervicovaginal smears might provide a milieu for growing some infectious agents, such as Trichomonas vaginalis and cocci. Lactobacilli were less plentiful in these cases. Vaginal discharge and abdominal pain were also important clinicalfindings for the detection ofALOs. Another finding was long-term usage of intrauterine contraceptive devices, which can cause the overgrowth of ALOs in vaginal mucosa.     

Relationship between the morphology of Candida cells and vaginal discharge

The aim of this study was to detect whether there is a correlation between the dimorphic pattern of Candida cells and various types of vaginal discharge. For this purpose, 2861 Papanicolaoustained cervicovaginal smears were examined cytologically and 265 of 2861 (9.26%) were diagnosed as having Candida cells. The 88 of 295 (29.83%) were identified as having blastospores only, 135 of 295 (45.76%) as having "hyphae only", and 47 of 295 (15.93%) as having both blastospores and hyphae of candida cells. There was a significant correlation between the type of candida cells and vaginal discharge (p < 0.05). The white-cheesy type vaginal discharge was the most prominent symptom for the observation the "hyphae only" following "blastospores only" and both blastospores and hyphae of Candida cells. It was suggested that hyphael form of Candida cells is the most pathogenic pattern and white-cheesy vaginal discharge is a marker for the presence of hyphael form in the vaginal mucosa.