Genetically-Tunable Mechanical Properties of Bacterial Functional Amyloid Nanofibers

Bacterial biofilms are highly ordered, complex, dynamic material systems including cells, carbohydrates, and proteins. They are known to be resistant against chemical, physical, and biological disturbances. These superior properties make them promising candidates for next generation biomaterials. Here we investigated the morphological and mechanical properties (in terms of Young’s modulus) of genetically-engineered bacterial amyloid nanofibers of Escherichia coli (E. coli) by imaging and force spectroscopy conducted via atomic force microscopy (AFM). In particular, we tuned the expression and biochemical properties of the major and minor biofilm proteins of E. coli (CsgA and CsgB, respectively). Using appropriate mutants, amyloid nanofibers constituting biofilm backbones are formed with different combinations of CsgA and CsgB, as well as the optional addition of tagging sequences. AFM imaging and force spectroscopy are used to probe the morphology and measure the Young’s moduli of biofilm protein nanofibers as a function of protein composition. The obtained results reveal that genetically-controlled secretion of biofilm protein components may lead to the rational tuning of Young’s moduli of biofilms as promising candidates at the bionano interface. © 2017 American Chemical Society

Monitoring of platelet function parameters and microRNA expression levels in patients with prostate cancer treated with volumetric modulated arc radiotherapy

Radiotherapy (RT) may result in platelet activation and thrombosis development. To the best of our knowledge, the potential effect of volumetric-modulated arc therapy (VMAT), a novel radiotherapy technique, on platelet function and microRNA (miRNA/miR) expression has not been previously investigated. The present study aimed to determine the effect of VMAT on the alterations in platelet function parameters and miRNA expression levels. A total of 25 patients with prostate cancer and 25 healthy subjects were included in the present study. Blood samples were collected from the patient group on the day prior to RT (pre-RT), the day RT was completed (post-RT day 0), and 40 days following the end of therapy (post-RT day 40). Platelet count, mean platelet volume (MPV) value, platelet aggregation, plasma P-selectin, thrombospondin-1, platelet factor 4, plasma miR-223 and miR-126 expression levels were measured. A significant decrease in platelet count in the post-RT day 0 group was measured in comparison with the pre-RT and the post-RT day 40 groups. Pre-RT MPV values were higher than those of the post-RT day 0 and the post-RT day 40 groups. No significant differences were observed in the levels of platelet activation markers or miR-223 and miR-126 expression levels between the RT groups. Although RT may result in a reduction in platelet and MPV counts, the results of the present study indicate that platelet activation markers are not affected by VMAT. Therefore, it is possible that no platelet activation occurs during VMAT, owing to the conformal dose distributions, improved target volume coverage and the sparing of normal tissues from undesired radiation

VDBP Gene Polymorphism in COPD

Chronic obstructive pulmonary disease (COPD) is a disease which genetic and environmental factors play an important role in COPD development. VDBP (Vitamin D Binding Protein ) gene might be responsible for COPD development. The purpose of this study to investigate the possible effect of VDBP on progression of COPD. We studied VDBP genotypes in 75 COPD patients, 36 smoker healthy subjects and 19 non-smoker healthy subjects with PCR-RFLP method to analyze the association between VDBP and COPD. In our study, the most frequently seen genotype was 1S-2 with a frequency of 32% in COPD group; and 1F-1S genotype with a frequency of 33.3% in smoker healthy group. There was no significant difference between these genotypes. In our study groups, we did not find any 2-2 genotype in non-smoker healthy subject group while it has been found 4% and 8% in COPD and healthy smoker subject groups, respectively. Although we did not find any significant difference for protective effect of the 2 allele on the disease or susceptibility of 1F allele to COPD formation in COPD patients and smoker healthy subjects (p: 0.346, p: 0.249, respectively), the only significant difference was between the patient and the healthy non-smoker groups with 1S-1S genotype (p=0.032). Our results do not show any evidence that indicate a protective or susceptibility effect of VDBP 2 and 1F alleles in progression of COPD, respectively but results indicate that having the 1S-1S genotype may be associated with the etiology of COPD. [Med-Science 2013; 2(1.000): 403-13

CT120: A New Potential Target for c-Myc in Head and Neck Cancers

Background: CT120 is a universally expressed protein with seven transmembrane domains. It functions in cell proliferation, survival and apoptosis by activating Raf/MEK/ERK and PI3K/Akt signaling pathways. Evidence suggests that CT120 plays important roles in lung carcinogenesis and oncogenic pathway activation. c-Myc is an important transcription factor modulating cell progression, apoptosis and cellular transformation. Previous studies have shown that MYC gene is amplified in many types of cancer including head and neck squamous cell carcinoma (HNSCC). Myc can regulate expression of many genes by binding to E-boxes. The aim of this study was to investigate the relationship between c-Myc protein and CT120 gene

The effects of mitochondrial DNA deletion and copy number variations on different exercise intensities in highly trained swimmers

It has been suggested that heavy exercise might increase oxidative stress, causing mitochondrial DNA (mtDNA) mutations as well as DNA mutations and changes in the mtDNA copy number in cells. mtDNA(4977) deletion is one of the most common deletions seen on mitochondria. We hypothesize association between exercise induced oxidative stress and mtDNA damage in peripheral blood lymphocytes (PBLs) of highly trained swimmers. Therefore we studied the mtDNA(4977) deletion level, mtDNA copy number and their relationship with cellular ATP and oxidative stress status in PBLs of swimmers. 8 highly trained and 8 normal trained swimmers and 8 non-athlete subjects were included in the study. The mtDNA(4977) deletion and amount of mtDNA were measured using RT-PCR method whereas dichlorohydrofluoroscein (DCF) assay method was used to assess cellular oxidative stress and ATP levels were measured using bioluminescence method. Even though an increase in mtDNA(4977) deletion was found in all study groups, the difference was not statistically significant (p=0.98). The mtDNA copy numbers were found to be surprisingly high in highly trained swimmers compared to normal trained swimmers and non-athlete subjects by 4.03 fold (p= 0.0002) and 5.58 fold (p= 0.0003), respectively. No significant differences were found between groups by means of intracellular ATP levels (p= 0.406) and oxidative stress (p= 0.430). No correlation was found between mtDNA copy number and intracellular ATP content of the PBLs (p= 0.703). Our results suggest that heavy training does not have a specific effect on mtDNA(4977) deletion but it may be affecting mitochondrial copy numbers which may act as a compensatory mechanism related to ATP levels in blood.İstanbul Üniversitesi Bilimsel Araştırma Projeleri Birimi - 4647

CT120

Background: CT120 is a universally expressed protein with seven transmembrane domains. It functions in cell proliferation, survival and apoptosis by activating Raf/MEK/ERK and PI3K/Akt signaling pathways. Evidence suggests that CT120 plays important roles in lung carcinogenesis and oncogenic pathway activation. c-Myc is an important transcription factor modulating cell progression, apoptosis and cellular transformation. Previous studies have shown that MYC gene is amplified in many types of cancer including head and neck squamous cell carcinoma (HNSCC). Myc can regulate expression of many genes by binding to E-boxes. The aim of this study was to investigate the relationship between c-Myc protein and CT120 gene. Methods: Tumor and normal tissue samples from 50 patients with HNSCC were investigated with chromatin immunoprecipitation assay (ChIP), Illumina MiSeq, bisulphite sequencing and qRT-PCR. Results: c-Myc binds to all E-boxes except E-box 5 on CT120 promoter. The CpG dinucleotides were found to be partially methylated in all tumor and normal tissue samples. Bisulphite sequencing showed a 10% down-regulation in the methylation levels of the tumor tissues. CT120 gene was hypomethylated and up-regulated in 56% of the tumor tissue samples. Expression of c-Myc was significantly higher in tumor tissues than in non-cancerous tissue samples. MYC was overexpressed in 68% of the tumor tissue samples compared to normal tissues. The mean MYC levels were 2.42-fold higher in the tumor tissue samples. In 48% of the tumor tissues, MYC and CT120A mRNA were up- or down-regulated simultaneously (p<0.001). Conclusion: We show that CT120 gene is a target of c-Myc and it contributes to cancer progression in HNSCC