Sibel Akyol

Pregnancy-Associated Exosomes and Their Modulation of T Cell Signaling

Exosome release by viable cells is a feature of activated cell types, including tumors, fetal cells, and cells of the immune system. Exosomes critically regulate immune activation, by mediating activation-induced cell death. Fetal cells may mimic these events to selectively delete reactive lymphocytes. In this study the presence and composition of placenta-derived exosomes are demonstrated in the maternal circulation along with their consequences on T cell activation markers. For all pregnant patients, exosomes were isolated from sera obtained between 28 and 30 wk gestation. For pregnant women, subsequently delivering at term, circulating levels of placental exosomes were 1.8 times greater than those delivering preterm (p < 0.0001). Exosomes isolated from pregnancies subsequently delivering at term expressed significantly higher levels of biologically active components, including Fas ligand (FasL) and HLA-DR, than those from pregnancies delivering preterm. Standardizing for protein concentrations, exosomes from term-delivering pregnancies exhibited greater suppression of CD3-ζ and JAK3 than those delivering preterm. The suppression of CD3-ζ and JAK3 correlated with exosome expression levels of FasL (r2 = 0.92 and r2 = 0.938, respectively). Fractionation of exosomes from term-delivering pregnancies by continuously eluting electrophoresis indicated that intact 42kD FasL and an unidentified 24-kDa protein were associated with CD3-ζ suppression. Our results demonstrated that exosomes from pregnancies ultimately delivering at term are present at significantly greater concentrations than those from pregnancies delivering preterm; however, exosomes from term-delivering pregnancies also exhibit significantly greater suppression of CD3-ζ and JAK3.

Catabolic cytokine expressions in patients with degenerative disc disease.

AIM Lumbar degenerative disc disease (DDD) is a common disease of advanced age characterized by progressive changes in the intervertebral disc and associated structures. There have been great efforts for years to explain its pathophysiological mechanism(s). This study aims to provide cytokine profile and in addition to the lymphocytes in a population of patients with lumbar DDD. MATERIAL AND METHODS Twenty-six patients whose clinical and radiological features were suggestive of lumbar DDD that underwent surgery and 14 autopsy cases as control were included. Patient disc samples were obtained during surgery whilst disc materials were collected during autopsy procedures from the controls. Major cytokines and lymphocytes were studied by using the flow cytometry method. RESULTS Significantly higher levels in disc samples in relation to IL-1β, IL-2, IL-4, IL-10, IL-12, TNF-α, CD8, CD56, CD19, and CD40 were found in the patients compared to the controls. Positive correlations were shown between CD3/CD4, CD25/CD3, CD25/CD4, CD19/CD4 but negative correlations were shown between CD19/CD3 and CD25/CD19 in both groups. CONCLUSION The findings suggest that both local inflammatory responses occur in lumbar DDD. Using specific cytokines either by local or systemic application may reverse the degenerative process.

Comparative Analysis of Tear Film Levels of Inflammatory Mediators in Contact Lens Users

ABSTRACT Purpose: To compare tear films levels of various inflammatory cytokines in asymptomatic contact lens (CL) users. CL users of rigid gas-permeable CLs (RGPCL) (group 1) or silicone hydrogel CLs (SiHCL) (group 2) were compared with non-CL-using healthy subjects (group 3). Materials and Methods: Tear samples were collected from subjects in each group after ensuring that there were no complications secondary to CL wear in the CL-wearing participants. Tear-film levels of interleukins (ILs)-1β, -6, and -8; granulocyte-macrophage colony-stimulating factor (GM-CSF) (using the Luminex method); and leukotriene B4 (LTB4) (using the ELISA method) were determined. Cytokine levels were compared among the three groups using analysis-of-variance (ANOVA) and Kruskall–Wallis tests. Results: There were significant differences in concentrations of IL-1β, GM-CSF and LTB4 among the three groups (p = 0.002, p = 0.021 and p = 0.009, respectively), as shown by the Kruskall–Wallis test comparing all three groups for the three cytokines. There were no significant differences for IL-6 and IL-8 (p = 0.079 and 0.094, respectively) when all three groups were compared. Conclusions: There were substantial statistically significant differences between RGPCL users, SiHCL users and control subjects in levels of tear film cytokines. Although CL users were asymptomatic, changes in tear-film levels of several important inflammatory mediators revealed that a chronic inflammatory process occurs during CL wear.

Relationship between lymphocytes, IL2 and the hormones E2, LH, PRG and FSH in menopausal and postmenopausal women.

Citation Akyol S, Cınar SA, Purisa S, Aydinli K. Relationship between lymphocytes, IL2 and the hormones E2, LH, PRG and FSH in menopausal and postmenopausal women. Am J Reprod Immunol 2011; 66: 304–309

TH1 and TH2 Cytokines Production and NK Cell Level Assessment in Peripheral Blood of Patients with DDH

In this study, our aim is; if the studies will quide us in peripheral blood, for the changes in inflammatory cytokine levels we defined before DDH tissue. Twenty-six patients were suggestive of lumbar DDH were included in this study. Control subjects included 14 autopsy cases. From each patient, disc tissues and peripheral blood samples for plasma were collected during the surgery. For the controls, disc samples and blood for plasma by intracardiac puncture were obtained during autopsy. The Flow Cytometry was used to obtain the lymphocyte CD56 (NK). The Luminex was used to obtain IL-2, IL-4, IL-10, IL-12, IFN-gamma, in both plasma and disc tissues. The results were compared between the two groups. Comparing the two groups regarding plasma demonstrated that IL–2, IL–4, IL–12, IFN-gamma were significantly higher than in patients than those of the controls. Likewise, tissue levels of IL–2, IL–4, IL–10, IL–12, TNF-alpha, CD56 were found to be significantly higher in the patients. With respect to the comparison between the plasma disc samples in the patients, plasma showed significant higher levels of IL-2, IL-12 on the other hand IL-4 was found to be significantly higher in the disc samples. Findings suggest that only tissue samples responses in occurring but not blood samples. We don’t think our results in peripheral blood will guide us specifically in DDH.

The effects of analgesia-sedation on the immune system before and after cerebral digital subtraction angiography.

AIM Cerebral digital subtraction angiography (DSA) is an invasive procedure and may cause inflammatory responses in the body. This study aims to provide cytokine and lymphocyte profile in a population of patients underwent cerebral DSA. MATERIAL AND METHODS Forty-one male patients who admitted for cerebral DSA were included in this study. Patients were divided into two groups: Group I (n = 7) included patients who did not receive analgesia-sedation and group II (n = 34) received analgesia-sedation before procedure. For the molecules, a venous blood samples from every patient was collected before and after cerebral DSA. RESULTS Cytokine levels in group I showed a trend to increase in the majority of the molecules after the procedure except IL-1β. In group II, cytokines showed variable trend. When comparing the two groups regarding cytokine levels after cerebral DSA, IL-1β, IL-10, IL-12, and IFN-γ levels increased significantly in group II. Comparing the two groups with respect to lymphocytes after cerebral DSA showed that CD56 levels were significantly higher in group II and other parameters did not show significant differences. CONCLUSION It can be possible that delimitation of the action(s) of the cytokines affecting the secretion or activation of CD56 (natural killer) may avoid complications of inflammation after invasive procedures.

Nanobioceramic thin films: Surface modifications and cellular responses on titanium implants

Abstract The relationship between biological responses and surface properties of materials is one of the main issues in biomedical materials research. A major disadvantage of current synthetic implants is their failure to adapt to the local tissue environment. In the dental and orthopedic fields, improvements in biocompatibility and the reliability of titanium and its alloys can be achieved through surface modifications. The purpose of altering the surfaces of metallic materials using biomedical thin films and nanocoatings is to promote bioactivity, reliability, and biocompatibility while at the same time eliminating or reducing corrosion and metal ion release. Important factors in determining the capability and performance of coated implants under physiological environments are the mechanical and adhesion properties. The design and success of an implant depends on a number of factors that includes materials, tissue implant interactions, biomechanical factors, and a patients health, which should be properly assessed. Furthermore, theoretical modeling approaches such as finite element analysis (FEA) are vital in the progress of understanding thin film-substrate interfacial behavior, which may result in better design and selection of thin film and substrate materials.

Electrohydrodynamic (EHD) Bioprinting of Polycaprolactone Scaffolds

This study is combined a 3D printing and Electrohydrodynamic (EHD) methods to fabricate a 3D PCL scaffolds for tissue engineering. Various kV values were applied to the different PCL solutions to investigate the effect of the voltage on scaffolds. The morphology of 3D-EHD printed PCL scaffolds were characterized by an Optical Microscope. 10 wt.% PCL up to 3 kV was obtained best sample to use for tissue engineering scaffolds.

The natural nano-bioceramic powder production from organ pipe red coral (Tubipora musica) by a simple chemical conversion method

The marine species are especially suited for the production of bioceramic nano-powders with natural methods for their use in the biomedical field. However, there are only very limited studies regarding the production and synthesis of hydroxyapatite (HAp) and tricalcium phosphate (TCP) nanomaterials from the marine structures. The structure of coral is very unique due to its similarity to bone because their structure consists of calcium carbonate that is the precursor for the synthesis of HAp. In this research, nano-bioceramic powders were produced from the organ pipe red coral (Tubipora musica) by two different simple chemical conversion methods under two different synthesis methods rather than the common hydrothermal method. The main advantages of these two methods are that they are simple and more economical in comparison to other methods used. All samples were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The size and shape of converted particles and structures were controlled by adjusting the calcination temperature and most importantly the agitation-mixing rate. According to XRD and SEM results, it can be concluded that the nano-scale monetite and other calcium phosphate powders were successfully obtained by these simple methods although retained calcium carbonate also observed due to the partial conversion.

Production of the novel fibrous structure of poly(ε-caprolactone)/tri-calcium phosphate/hexagonal boron nitride composites for bone tissue engineering

Nanofibrous composites of the poly(ε-caprolactone) (PCL), tricalcium phosphate (TCP), and hexagonal boron nitride (h-BN) with different compositions were manufactured by using an economical and non-complicated method called electrospinning. Produced fibrous structures showed no bead formation and had a clean surface. Characterization of the composites showed that particles were successfully mixed with polymer phase. High cell activity of SaOS-2 cells on the composites was observed with SEM images. In addition, fibrous scaffolds are biocompatible with human bone tissue and are highly degradable.