Ozlem Bingol Ozakpinar

The Novel Function of Nesfatin-1 as an Anti-inflammatory and Antiapoptotic Peptide in Subarachnoid Hemorrhage–Induced Oxidative Brain Damage in Rats

BACKGROUND:There is substantial evidence to suggest that oxidative stress plays a significant role in the development of acute brain injury after subarachnoid hemorrhage (SAH). OBJECTIVE:To investigate the putative neuroprotective effect of nesfatin-1, a novel peptide with anorexigenic properties, in a rat model of SAH. METHODS:Male Wistar albino rats were randomly divided into control, saline-treated SAH, and nesfatin-1 (10 μg/kg IP)-treated SAH groups. To induce SAH, rats were injected with 0.3 mL blood into their cisterna magna. Forty-eight hours after SAH induction, neurological examination scores were recorded and the rats were decapitated. Brain tissue samples were taken for the determination of blood-brain barrier (BBB) permeability, brain water content, and oxidative stress markers and for histological analysis. RESULTS:The neurological examination scores were increased on the second day of SAH induction. SAH resulted in impaired blood-brain barrier and edema, along with increased levels of brain tumor necrosis factor-α, interleukin-1β, interleukin-6, lipid peroxidation, protein carbonylation, and myeloperoxidase activity with concomitant decreases in antioxidant enzymes. Conversely, in the nesfatin-1-treated SAH group, SAH-induced neurological impairment and oxidative brain injury were ameliorated by nesfatin treatment. Furthermore, SAH-induced morphological changes in the basilar arteries were improved by nesfatin-1 treatment, whereas caspase-3 activity and SAH-induced elevations in the plasma levels of proinflammatory cytokines were also depressed by nesfatin-1 treatment. CONCLUSION:These findings suggest that nesfatin-1, which appears to have antiapoptotic and anti-inflammatory properties, exerts neuroprotection in SAH-induced injury in rats by inhibiting neutrophil infiltration and subsequent release of inflammatory mediators.

Blood Serum and Seminal Plasma Selenium, Total Antioxidant Capacity and Coenzyme Q10 Levels in Relation to Semen Parameters in Men with Idiopathic Infertility

In this case–control study, we aimed to evaluate the serum and seminal plasma levels of Selenium (Se), total antioxidant capacity (TAC), and Coenzyme Q10 (CoQ-10) and determine their relationship with sperm concentration, motility, and morphology in men with idiopathic infertility. A total of 59 subjects were enrolled in the study. Forty four patients were diagnosed with idiopathic male infertility and had abnormal sperm parameters, and 15 subjects had normal sperm parameters with proven fertility. Serum Se, semen Se, and semen TAC levels were significantly different in the fertile and infertile groups (p < 0.01, p < 0.001, and p < 0.001, respectively). However, serum TAC, serum, and seminal plasma CoQ-10 levels did not differ between fertile and infertile groups. When the levels of the measured parameters were compared in serum and seminal plasma, serum levels of Se were found to be correlated positively with the semen levels in all subjects included into the study (N = 59) (r = 0.46, p < 0.01). A relationship was found between neither serum and semen levels of TAC nor between serum and semen levels of CoQ-10. Correlations among measured serum and semen parameters with sperm parameters demonstrated that both the serum and semen levels of Se were correlated positively with spermatozoa concentration, motility, and morphology. Additionally, seminal plasma levels of TAC correlated positively with all these sperm parameters. On the other hand, seminal plasma levels of CoQ-10 correlated only with sperm morphology but not with concentration or motility. No relationship was observed between serum levels of TAC or serum levels of CoQ-10 and sperm parameters. In conclusion, serum and seminal plasma Se deficiency may be a prominent determinant of abnormal sperm parameters and idiopathic male infertility. Measurement of serum Se levels may help determine nutritional status and antioxidant capacity in infertile patients, which may help distinguish those patients who will benefit from supplementation therapy.

Obestatin alleviates subarachnoid haemorrhage-induced oxidative injury in rats via its anti-apoptotic and antioxidant effects

Abstract Objective: The aim was to investigate the putative anti-inflammatory and anti-apoptotic effect of obestatin in a rat model of subarachnoidal haemorrhage (SAH). Methods: To induce SAH, rats were injected with 0.3 mL blood into their cisterna magna. At 48 hours rats were decapitated after neurological examination. Blood–brain barrier (BBB) permeability, brain water content, oxidative stress markers and histological analysis were done in brain tissue. Results: The results showed that neurological examination scores were increased in the SAH group and, moreover, BBB permeability was impaired and oedema formed. SAH resulted in increased levels of plasma tumour necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 levels and caspase-3 activity. Lipid peroxidation and protein oxidation levels and myeloperoxidase activity were all increased in the brain tissue, with concomitant decreases in antioxidant enzymes. On the other hand, SAH-induced neurological impairment and oxidative brain injury were ameliorated in the obestatin-treated group. Conclusion: The present study provides the first evidence that peripheral administration of obestatin exerts potent anti-inflammatory and neuroprotective effects in SAH-induced oxidative damage by maintaining a balance in oxidant-antioxidant status through the augmentation of endogenous antioxidants and the inhibition of pro-inflammatory mediators.

The impact of platelet functions and inflammatory status on the severity of preeclampsia

Abstract Objective: To find out whether there is a correlation between the extent of platelet activation and inflammation and the severity of preeclampsia (PE) in the third trimester of pregnancy. Methods: Forty-one women with PE (n = 23 severe, n = 18 mild) and 80 normotensive pregnant (NP) women were included in the study. Their blood samples were obtained and interleukin (IL)-8 and IL-10 levels measured by an enzyme-linked immunosorbent assay. Basal CD61 and CD62P expressions on CD41-positive platelets were analyzed with the use of flow-cytometry. Platelet aggregation was induced by adenosine diphosphate and determined by aggregometry. Results: CD62P expression was increased in severely preeclamptic women, and the platelet aggregation was decreased in both mildly and severely preeclamptic women in comparison with NP women. However, CD61 expression was similar among the groups. An enhanced inflammatory response was seen in severely preeclamptic women demonstrated by increased levels of IL-8 and decreased levels of IL-10. However, the intensity of platelet activation did not correlate directly with the change in plasma levels of IL-8 and IL-10 in preeclamptic women. Conclusions: Platelets may have a role in the inflammatory response in PE. However, the severity of inflammation is found to be independent from the intensity of platelet activation in preeclamptic women. This seems to be related to mechanisms causing alterations of cytokine levels such as IL-8 and IL-10, rather than platelet activation.

Protective effect of ferulic acid on cisplatin induced nephrotoxicity in rats

This study aims to determine the potential protective effects of ferulic acid against cisplatin-induced nephrotoxicity and to compare its effect with curcumin, a well-known protective agent against cisplatin- induced toxicity in rats. Administration of cisplatin resulted in high BUN (Blood Urea Nitrogen), creatinine, MDA (Malondialdehyde), MPO (Myeloperoxidase), TOS (Total Oxidative Status), PtNT (Protein Nitrotyrosine) levels (p<0.05). Histological observations showed abnormal morphology of kidney; in addition with appearance of TUNEL positive cells indicating apoptosis in cisplatin administered group. HO-1 (Heme Oxygenase-1) levels measured by RT-PCR (Real Time Polymerase Chain Reaction), and TAS (Total Antioxidative Status) revealed antioxidant depletion due to cisplatin toxicity in animals (p<0.05). All parameters showed improvement in groups treated with ferulic acid (p<0.05). Ferulic acid treatment was found significant in preventing oxidative stress, increasing antioxidative status and regaining histological parameters to normal, indicating nephroprotective and antioxidant effects of this phenolic compound.

Ovarian stem cells: From basic to clinical applications

The field of reproductive biology has undergone significant developments in the last decade. The notion that there is a fixed reserve pool of oocytes before birth was established by Zuckerman in 1951. However, in 2004, an article published in nature challenged this central dogma of mammalian reproductive biology. Tillys group reported the existence of ovarian germline stem cells (GSCs) in postnatal ovaries of mice and suggested that the bone marrow could be an extragonadal source of ovarian GSCs. These findings were strongly criticized; however, several independent groups have since successfully isolated and characterized ovarian GSCs in postnatal mice. The ovarian GSCs are located in the ovarian surface epithelium and express markers of undifferentiated GSCs. When transplanted into mouse ovaries, mouse ovarian GSCs could differentiate and produce embryos and offspring. Similarly, in a recent study, ovarian GSCs were found to be present in the ovaries of women of reproductive age. Conversely, there is increasing evidence that stem cells responsible for maintaining a healthy state in normal tissue may be a source of some cancers, including ovarian cancer. Cancer stem cells (CSCs) have been found in many tissues, including ovaries. Some researchers have suggested that ovarian cancer may be a result of the transformation and dysfunction of ovarian GSCs with self-renewal properties. Drug resistant and metastasis-generating CSCs are responsible for many important problems affecting ovarian cancer patients. Therefore, the identification of CSCs will provide opportunities for the development of new therapeutic strategies for treatments for infertility and ovarian cancer. In this article, we summarize the current understanding of ovarian GSCs in adult mammals, and we also discuss whether there is a relationship between GSCs and CSCs.

The protective effects of tacrolimus on rat uteri exposed to ischemia-reperfusion injury: a biochemical and histopathologic evaluation

OBJECTIVE To evaluate the effects of the immunosuppressant tacrolimus as an antioxidant and analyze the histopathologic changes in rat uteri exposed to experimental ischemia-reperfusion (I/R) injury. DESIGN Experimental study. SETTING Experimental surgery laboratory in a university. ANIMAL(S) Twenty-eight female rats exposed to experimentally induced uterine I/R injury. INTERVENTION(S) Group I: control group; group II: uterine I/R injury-induced group; group III: pre-ischemia tacrolimus group; group IV: post-ischemia tacrolimus group. MAIN OUTCOME MEASURE(S) Uterine tissue malondialdehyde (MDA) level as a marker of lipid peroxidation and glutathione (GSH) level and superoxide dismutase (SOD) and catalase (CAT) activities as markers of tissue antioxidant capacity; histopathologic examination of all uterine rat tissue. RESULT(S) Following aortic I/R injury, MDA levels were significantly increased whereas GSH levels and CAT and SOD activities were found to be decreased compared with control animals. MDA levels were found to recover prominently after the administration of tacrolimus in both groups III and IV. Administration of tacrolimus improved uterine GSH levels and CAT activity in the tacrolimus-treated groups. CONCLUSION(S) Our results indicate that tacrolimus reduces oxidative damage in rat uteri exposed to I/R injury induced by distal abdominal aortic occlusion. Histologic evaluation reveals that tacrolimus attenuates the inflammatory response and protects the tissue damage induced by I/R injury.

Association between the growth arrest-specific 6 (Gas6) gene polymorphism c.834 + 7G>A and preeclampsia

Abstract Objective: Preeclampsia (PE) is a hypertensive disease of pregnancy complicating 2–8% of all pregnancies. The exact pathophysiology still remains unknown. Growth arrest-specific 6 (Gas6) is a member of the vitamin K-dependent protein family and it has been suggested as a novel atherothrombotic risk factor with anti-angiogenic and pro-atherogenic properties. The goal of the our study was to investigate the relationships between the c.834 + 7G > A polymorphism of GAS6, plasma Gas6 levels and PE. Methods: A total of 150 women, including 82 preeclamptic pregnant women and 68 normotensive pregnant (NP) women, were recruited in the current study. Blood samples were taken from all participitants. Plasma Gas6 levels measured by an enzyme-linked immunosorbent assay. GAS6 polymorphism was determined using a PCR-RFLP method. Results: The plasma Gas6 levels of preeclamptic patients were significantly lower than those of NP women (8.65 ± 3.70 ng/ml and 10.89 ± 4.23 ng/ml respectively, p < 0.001). The GG genotype was the most prevalent, and the risk of PE was 3.5-fold higher in pregnant women with GG genotype compared to woman with AA genotype (p < 0.01). The A allele was less frequent in preeclamptic patients than in control subjects (OR = 2.118, 95% CI = 1.330–3.371, p < 0.001). Conclusions: Our results suggest that GAS6 c.834 + 7G > A polymorphism may have a pivotal role in the pathogenesis of PE suggesting that the A allele has a protective role for PE.

Growth Arrest-Specific 6 (Gas6) and TAM Receptors in Mouse Platelets.

Objective: Growth arrest-specific 6 (Gas6) is a newly discovered vitamin K-dependent protein, which is a ligand for TAM receptors [Tyro3 (Sky), Axl, and Mer] from the tyrosine kinase family. Gas6 knockout mice were resistant to venous and arterial thrombosis. There are contradictory reports on the presence of Gas6 and its receptors in mouse platelets. The objective of this study was to investigate whether Gas6 and its receptors were present in mouse platelets or not. Materials and Methods: Specific pathogen-free BALB/c male and female mice of 8-10 weeks old and 25-30 g in weight were anesthetized under light ether anesthesia and blood samples were taken from their hearts. RNAs were isolated from isolated platelets, and then mRNAs encoding Gas6 and TAM receptors were detected by reverse transcription-polymerase chain reaction (RT-PCR). Protein concentrations of Gas6 and TAM receptors in platelets were measured by ELISA, but not those of Mer, because of the absence of any commercial ELISA kit for mouse specimens. Results: RT-PCR results indicated the presence of mRNAs encoding Gas6 and Mer in mouse platelets. However, although RT-PCR reactions were performed at various temperatures and cycles, we could not detect the presence of mRNAs encoding Axl and Tyro3 (Sky). Receptor protein levels of Axl and Tyro3 were below the detection limits of the ELISA method. Conclusion: We found the presence of mRNAs encoding Gas6 and the receptor Mer in mouse platelets, but not Axl and Tyro3. Gas6, Axl, and Tyro3 protein levels were below the detection limits of the ELISA. The presence of mRNA is not obvious evidence of protein expression in platelets that have no nucleus or DNA. Further studies are required to clarify the presence of Gas6/TAM receptors in platelets using real-time PCR and more sensitive immunological methods, and future studies on mechanisms will indicate whether the Gas6/TAM pathway is a strategy for treatment of disorders.

Platelets in Preeclampsia: Function and Role in the Inflammation

Preeklampsi tüm gebeliklerin %5-8’ ini komplike eden gebeliğin hipertansif hastalığıdır. Preeklampsi patogenezinde kılcal damar yatağındaki inflamasyon önemli rol oynar. Preeklampside olduğu gibi dolaşımda serbest halde bulunan mikropartiküllerle trombositlerin karşılaşması sonucunda trombositler aktive olurlar. Aktive olan trombositler dolaşıma serbest moleküller salarlar ve hücre yüzeylerindeki adhezyon moleküllerinin artmasına neden olurlar. Serbest moleküller trombosit, lökosit ve endotel hücreleri arasındaki etkileşimleri düzenlerler. Adhezyon molekülleri de trombosit, lökosit ve endotel hücrelerinin birbirlerine bağlanmasına aracılık ederler. Oluşan trombosit-lökosit agregatları nötrofillerin inflamasyonun olduğu damarsal yapılara göçünün artmasına neden olur. Ayrıca, endotel hücrelerine bağlanan trombositler sitokinlerin yapımına ve inflamatuvar yanıtın artmasına neden olur. Bu derlemede, preeklamptik gebelerde trombosit fonksiyon bozuklukları ve trombositlerin preeklampsi patogenezindeki inflamatuvar rolünden bahsedeceğiz. Anahtar sözcükler: Preeklampsi, trombosit aggregasyonu, trombosit aktivasyonu, inflamasyon ABS TRACT Platelets in preeclampsia: function and role in the inflammation