Tumour necrosis factor alpha, lipid peroxidation and NO* are increased and associated with decreased free-radical scavenging enzymes in patients with Weill-Marchesani syndrome.

AIM: Weill-Marchesani syndrome (WMS) is a rare systemic disorder with both autosomal recessive and dominant inheritances. Accumulation of reactive oxygen species such as O2*-, H2O2 and OH* causes lipid peroxidation (LPO), whereas antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GSHPx)) mediate defence against oxidative stress. Excess tumour necrosis factor (TNF)-alpha and NO* react with O2*- and cause further antioxidant depletion with an increase in mutation frequency by H2O2. This study investigated the levels of SOD, GSHPx, catalase (CAT), TNF-alpha, NO and LPO in patients with WMS. METHODS: A group of 10 WMS patients (four males, six females; age, 26.5+/-19.0 years) and 10 age-matched and sex-matched controls (five males, five females; age, 27.3+/-18.2 years) were included. Serum TNF-alpha levels were determined by a spectrophotometer technique using immulite chemiluminescent immunometric assay. Malondialdehyde (MDA) was determined in plasma; CAT in red blood cells (RBCs), and SOD and GSHPx in both plasma and RBCs. Total serum NO* levels were evaluated by Griess reaction. RESULTS: Mean levels of TNF-alpha (8.3+/-0.6 pg/ml) in WMS patients were significantly (p<0.001) higher than controls (4.3+/-0.2 pg/ml). Plasma MDA levels in patients and controls were 5.4+/-0.8 and 1.8+/-0.6 micromol/l, respectively, and the difference was significant (p=0.0002). SOD and GSHPx activities were significantly lower in both RBCs and plasma of WMS than in controls (RBC-SOD, 3981.9+/-626.6 versus 5261.6+/-523.0 U/g haemoglobin (Hb), p=0.0005; plasma-SOD, 529.4+/-49.3 versus 713.4+/-55.7 U/g protein, p=0.0002; RBC-GSHPx, 682.7+/-42.0 versus 756.5+/-47.6 U/g Hb, p=0.0011; plasma-GSHPx, 107.3+/-15.0 versus 131.4+/-19.7 U/g protein, p=0.0113). In addition, serum NO (NO*-2 + NO*-3) levels were also significantly (p = 0.0002) increased in WMS patients (54.4+/-5.7 versus 26.9+/-6.7 micromol/l). RBC-CAT levels were similar between groups (125.6+/-21.3 versus 131.0+/-21.5 k/g Hb, p = 0.8798). CONCLUSIONS: The elevated LPO, TNF-alpha and NO* with decreased antioxidant enzyme activities indicated impaired antioxidative defence mechanisms with an oxidative injury and cell toxicity in WMS patients. The use of multiple antioxidants and free radical scavengers might be helpful in this genetic disorder

RBPjk-Independent, NICD-Dependent Signals in Rbpj-/- Hair Follicle Keratinocytes Cause a Milder Phenotype in RBPjcKO Animals

Notch is a membrane-bound transcription factor that mediates signals between adjacent cells. It is the central member of a highly conserved pathway that is important for proliferation, cell fate decisions, and apoptosis not only during development, but also in adulthood acting either in stem cell maintenance or differentiation. In the skin, Notch is essential for epidermal differentiation, maintenance of hair follicle morphology and terminal differentiation of the inner and outer root sheath cells. Ligand-dependent activation, gamma-secretase-dependent cleavage, and RBPjk-mediated downstream transcriptional activities of Notch receptors constitute the canonical Notch signaling pathway. This implies that loss of gamma-secretase (no Notch Intracellular Domain (NICD) release), Notch receptors (no NICD), or RBPjk (no activation of downstream targets) should generate similar phenotypes based on the canonical model. Unexpectedly, keratinocyte-specific deletion of Rbpj gene (RBPjcKO) produced a significantly milder phenotype than the keratinocyte-specific deletion of both Notch1 and Notch2 genes (N1N2dcKO) or Presenilin1 and Presenilin2 genes (PSdcKO). Based on these observations, we sought to determine the underlying mechanisms and investigated the potential role of non-canonical Notch signaling in generating these phenotypic differences. First, we characterized N1N2dcKO, PSdcKO, and RBPjcKO embryonic skin. We found that all these mutants are similar at birth with no significant differences in the gross morphology of their epidermis and hair follicles as well as mRNA and protein expression patterns. Secondly, we genetically dissected the Notch signaling pathway to define the elements ameliorating the phenotype. We showed that even a limiting amount of cleaved Notch1ICD is sufficient for the milder phenotype observed in RBPjcKO animals. Lastly, we showed that the loss of Notch signaling in the hair follicles drives the severe phenotypes in PSdcKO and N1N2dcKO animals. Although the levels of epidermal TSLP expression are similar in all Notch mutants, RBPjcKO hair follicles are less distorted and produce less TSLP leading to lower serum TSLP levels. The reduced TSLP in serum results in less aggressive B cell expansion allowing RBPjcKO animals to live significantly longer than N1N2dcKO and PSdcKO animals. In conclusion, gamma-secretase cleaved Notch1ICD likely stimulate RBPjk-independent signals in the Rbpj-/- hair follicle keratinocytes causing a milder phenotype in RBPjcKO animals. Future experiments will interrogate whether RBPjk-independent NICD activity directly generates a different transcriptional response or affects other signaling pathways

Silver release of Ag (I) doped hydroxyapatite: In vitro study

Turkoz, Mustafa Burak/0000-0002-4127-7650; Erdem, Umit/0000-0002-0480-8176WOS: 000471903000002PubMed: 30901135A material is produced by doping of silver (Ag (I)) which has antibacterial property to nano hydroxyapatite (nHAp), to remove the hipersensitivity in the teeth by closing the dentine tubules or dental micro cracks of the teeth and effective against for some bacteria. The doping of Ag (I) can also produces a toxic effect. Ag (I) can be released from the structure as a result of biological, physical and chemical effects and may cause toxicity. Therefore, it is important to determine whether the presence of Ag (I) has a toxic effect. In this study, Ag (I)-doped nHAp was synthesized by precipitation method and tried to determine the release values as a function of time compared to the doping rate by using the ICP-OES. Also, the products we produce in simulated body fluid were kept for retention periods of 4-20 weeks to determine degradation percentages. A cytotoxicity study was performed to observe the toxic effect that may be caused by possible Ag (I) release. According to the analysis, the release values in all products were observed in ppb level. And it is concluded that the materials produced are not degraded. Cell viability values of more than 70% were obtained. It was observed that the release of Ag (I) bound to Ag (I)-doped nHAp hexagonal structure was very low. It was concluded that the products are not degraded and Ag (I)-doped nHAp to a certain ratio is a biocompatible material that can be used in dentistry for treatment

Dentinal tubule occluding capability of nano-hydroxyapatite; The in-vitro evaluation

Turkoz, Mustafa Burak/0000-0002-4127-7650; dogan, mustafa/0000-0002-3782-8640; Dogan, Mustafa/0000-0002-4437-566X; Erdem, Umit/0000-0002-0480-8176WOS: 000448889100005PubMed: 29707852In this in-vitro study, the effectiveness of experimental pure nano-hydroxyapatite (nHAP) and 1%, 2%, and 3% F doped nano-HAp on dentine tubule occlusion was investigated. And also, the cytotoxicity of materials used in the experiment was evaluated. Nano-HAp types were synthesized by the precipitation method. Forty dentin specimens were randomly divided into five groups of; 1no treatment (control), 2specimens treated with 10% pure nano-HAp and 3, 4, 5 specimens treated with 1%, 2%, and 3% F(-)doped 10% nano-HAp, respectively. To evaluate the effectiveness of the materials used; pH, FTIR, and scanning electron microscopy evaluations were performed before and after degredation in simulated body fluid. To determine cytotoxicity of the materials, MTT assay was performed. Statistical evaluations were performed with F and t tests. All of the nano-HAp materials used in this study built up an effective covering layer on the dentin surfaces even with plugs in tubules. It was found that this layer had also a resistance to degradation. None of the evaluated nano-HAp types were have toxicity. Fluoride doping showed a positive effect on physical and chemical stability until a critical value of 1% F-. The all evaluated nano-HAp types may be effectively used in dentin hypersensitivity treatment. The formed nano-HAp layers were seem to resistant to hydrolic deletion. The pure and 1% F(-)doped nano-HAp showed the highest biocompatibility thus it was assessed that pure and 1% F(-)doped materials may be used as an active ingredient in dentin hypersensitivity agents

Silver and fluoride doped hydroxyapatites: Investigation by microstructure, mechanical and antibacterial properties

Turkoz, Mustafa Burak/0000-0002-4127-7650; Evis, Zafer/0000-0002-7518-8162WOS: 000325835100048Hydroxyapatite co-doped with Ag+ and F- ions was synthesized by the precipitation method and sintered at 1100 degrees C for 1 h. Samples were characterized by density, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and scanning electron microscopy to investigate their microstructure, phase formation and bonding characteristics. Moreover, samples were also characterized by microhardness and antibacterial tests. Small amount of dopings resulted in high densities and fine grain microstructures. In most of the samples, hydroxyapatite was the main phase with a minor amount of beta-TCP. Presence of fluoride and small amount of TCP was verified with all characteristic FTIR bands of hydroxyapatite for most of the samples. Compared to the pure hydroxyapatites, much higher microhardness values were measured in samples co-doped with Ag+ and F- ions. Antibacterial activity of the materials related to Escherichia coli was also observed in hydroxyapatite samples with high amount of Ag+ ions. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved

Hydroxyapatite-based nanoparticles as a coating material for the dentine surface: An antibacterial and toxicological effect

Turkoz, Mustafa Burak/0000-0002-4127-7650; Dogan, Mustafa/0000-0002-4437-566XWOS: 000498748300032In this study, nano sized hydroxyapatite (nHAp) and Ag(I) doped hydroxyapatite (Ag-nHAp) particles were synthesized by the precipitation method and used as a coating material for remineralization on caries-affected dentine samples. Characterization studies of both the synthesized hydroxyapatite-based particles and the coated dentine samples were performed using instrumental techniques such as SEM and FFIR, and then toxicity and antibacterial properties were also evaluated. It was observed that dentine samples were effectively coated by both nHAp and Ag center dot nHAp particles which have no toxic effects. Furthermore, the costing of nano-hydroxyapatite on dentine samples positively contributed to the viability of L929 fibroblast cells and also provided an antibacterial effect against to bacteria such as S. mutants, C. albicans and E. coli bacteria that are most frequently caused caries in the teeth. While all type of bacteria was eliminated by the nHAp coated dentine samples at 24th, Ag-nHAp coated dentine samples removed to all bacteria type at 1st.Kirikkale University Research FundKirikkale University [2019/038]The authors would like to express their gratitude to Kirikkale University Research Fund for its financial support. Project Number: 2019/038

Class I Major Histocompatibility Complex Presentation of Antigens That Escape from the Parasitophorous Vacuole of Toxoplasma gondii

The intracellular parasite Toxoplasma gondii, the causative agent of toxoplasmosis, induces a protective CD8 T-cell response in its host; however, the mechanisms by which T. gondii proteins are presented by the class I major histocompatibility complex remain largely unexplored. T. gondii resides within a specialized compartment, the parasitophorous vacuole, that sequesters the parasite and its secreted proteins from the host cell cytoplasm, suggesting that an alternative cross-priming pathway might be necessary for class I presentation of T. gondii antigens. Here we used a strain of T. gondii expressing yellow fluorescent protein and a secreted version of the model antigen ovalbumin to investigate this question. We found that presentation of ovalbumin secreted by the parasite requires the peptide transporter TAP (transporter associated with antigen processing) and occurs primarily in actively infected cells rather than bystander cells. We also found that dendritic cells are a major target of T. gondii infection in vivo and account for much of the antigen-presenting activity in the spleen. Finally, we obtained evidence that Cre protein secreted by T. gondii can mediate recombination in the nucleus of the host cell. Together, these results indicate that Toxoplasma proteins can escape from the parasitophorous vacuole into the host cytoplasm and be presented by the endogenous class I pathway, leading to direct recognition of infected cells by CD8 T cells

Loss of RBPj in postnatal excitatory neurons does not cause neurodegeneration or memory impairments in aged mice.

Previous studies suggest that loss of γ-secretase activity in postnatal mouse brains causes age-dependent memory impairment and neurodegeneration. Due to the diverse array of γ-secretase substrates, it remains to be demonstrated whether loss of cleavage of any specific substrate(s) is responsible for these defects. The bulk of the phenotypes observed in mammals deficient for γ-secretase or exposed to γ-secretase inhibitors are caused by the loss of Notch receptor proteolysis. Accordingly, inhibition of Notch signaling is the main cause for untoward effects for γ-secretase inhibitors as therapeutics for Alzheimer's disease. Therefore, we wished to determine if loss of canonical Notch signaling is responsible for the age-dependent neurodegeneration observed upon γ-secrectase deficiency in the mouse brain. We generated postnatal forebrain-specific RBPj conditional knockout (cKO) mice using the CamKII-Cre driver and examined behavior and brain pathology in 12-18 month old animals. Since all four mammalian Notch receptor homologues signal via this DNA binding protein, these mice lack canonical Notch signaling. We found that loss of RBPj in mature excitatory neurons was well tolerated, with no evidence for neurodegeneration or of learning and memory impairment in mice aged up to 18 months. The only phenotypic deficit we observed in the RBPj-deficient mice was a subtle abnormality in olfactory preferences, particularly in females. We conclude that the loss of canonical Notch signaling through the four receptors is not responsible for age-dependent neurodegeneration or learning and memory deficits seen in γ-secretase deficient mice

Influence of Radiation Exposure During Radiotherapy Evidence for the Increase of Versican and Heparin-Binding EGF-like Growth Factor Concentrations

WOS: 000381062200009PubMed: 27386634OBJECTIVE: To investigate the reaction of versican and heparin-binding EGF-like growth factor (HB-EGF) molecule concentrations to acute radiation exposure in normal bladder and rectal tissue samples in order to gain more insight into the effects of cancer radiotherapy. STUDY DESIGN: Four groups with 6 male adult Swiss Albino mice per group were investigated. The mice bladder and rectum tissue samples were subjected to a 10-Gy single-dose radiation exposure in the pelvic region with a Co-60 teletherapy device and investigated 1, 2, and 7 days after radiation exposure, with 1 reference group which was not exposed to radiation. RESULTS: In the immunohistochemical examination of the tissue samples with anti-versican and anti-HB-EGF primary antibodies was observed a statistically significant increase 7 days after radiation exposure. CONCLUSION: The observed increase of versican and HB-EGF concentrations in the normal tissue matrix after radiation exposure may play a role in the side effects of radiotherapy