Kemal Ergin

Protective Effects of Caffeic Acid Phenethyl Ester on Intestinal Ischemia-Reperfusion Injury

Aim Intestinal ischemia reperfusion (IR) causes tissue injury in two ways, starting a pro-inflammatory cascade and oxidative stress. The aim of this study was to investigate the possible protective effects of caffeic acid phenethyl ester (CAPE), which has antioxidant and anti-inflammatory properties, against intestinal IR injury in rats. Materials and Methods Forty male Wistar-Albino rats were divided into five groups: Sham, IR, IR plus ethanol (vehicle), IR plus 10 mg/kg (IR + 10CAPE), and 30 mg/kg CAPE (IR + 30CAPE) at the 30-min ischemic period. Intestines were exteriorized and the superior mesenteric artery was occluded for 45-min ischemia and then the clamp was removed for 120-min reperfusion. After the experiment, the intestines were removed for biochemical and light microscopic examinations. Additionally, blood samples were taken for plasma TNF-α measurement. Results The TBARS levels of the IR and IR + Ethanol groups were higher than the Sham group (P < 0.05). Both CAPE treatments decreased TBARS levels in comparison with the IR group (P < 0.05). In both CAPE-treated groups, while the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were increased compared to all other groups, which was similarly the case for the CAT activity compared to the Sham and IR + Ethanol groups (P < 0.05). There were no significant differences between GSH levels of all study groups. The TNF-α levels of the IR and IR + Ethanol groups were non-significantly increased compared to the Sham group (P > 0.05). The TNF-α levels of 10 and 30 mg/kg CAPE groups were non-significantly decreased compared to the IR group (P > 0.05). The tissue MPO activities of the IR and IR + Ethanol groups were higher than the Sham group (P < 0.05). The MPO activities of the IR + 10CAPE and IR + 30CAPE groups were not significantly different from the Sham group (P > 0.05). There was necrosis of mucosa in the IR and IR + Ethanol groups in light microscopic evaluations. Those changes were significantly reversed by 30 mg/kg CAPE treatment. Conclusion The intestinal IR injury may be reversed by anti-inflammatory and antioxidant actions of the CAPE. However, 30 mg/kg CAPE treatment may be more efficient in preventing intestinal IR injury in rats.

Melatonin ameliorates blood-brain barrier permeability, glutathione, and nitric oxide levels in the choroid plexus of the infantile rats with kaolin-induced hydrocephalus.

Hydrocephalus is a disabling disease for children, but current data concerning the effects of melatonin on ventricular enlargement are still limited. We have investigated the changes in the choroid plexuses (CPs) of ventricles and blood-brain barrier (BBB) of hydrocephalic rats. Forty-five Swiss Albino rats at age 2 weeks were divided into three equal groups: control, hydrocephalus, and melatonin-treated hydrocephalus groups. Hydrocephalus was induced by kaolin injection into the cisterna magna of all pups except control group and melatonin was given at a daily dose of 0.5 mg/100 g body weight for 4 weeks. At the end of the study, one animal from each group was examined using a gamma camera to study the disruption of BBB due to hydrocephalus. All animals were then killed for assay of glutathione (GSH) and nitric oxide (NO), as well as histological study of the CPs during the hydrocephalus. We observed an increased BBB activity was found in hydrocephalus group, while melatonin reversed these changes. It was found that NO concentration was elevated in hydrocephalus group and melatonin partly abolished the increased levels of NO. In contrast, GSH levels were significantly decreased in hydrocephalus group, while melatonin increased the tissue GSH level (p<0.01). Histologically, there was a significant alteration in the CPs of the ventricles of hydrocephalic animals, but it was regressed after melatonin treatment in consistent with the gross morphological changes related to hydrocephalus. In conclusion, our results clearly demonstrated for the first time the neuroprotective effects of melatonin upon hydrocephalus-induced CP changes in infantile rats, but further studies are needed to suggest melatonin as a candidate protective drug in children.

Effects of sunitinib and bevacizumab on VEGF and miRNA levels on corneal neovascularization

Abstract Aim: To evaluate the effects of sunitinib (0.5 mg/ml) and bevacizumab (5 mg/ml) on VEGF-A, VEGFR-2 and microRNA (miRNA) levels on corneal neovascularization (CNV). Methods: In this study, CNV was induced by silver nitrate application to the cornea, and 40 Albino male rats were equally divided into four subgroups: Group 1 (sunitinib): After silver nitrate application to the cornea, 0.5 mg/ml sunitinib eyedrop was administered twice daily for two weeks (n = 10). Group 2 (bevacizumab): After silver nitrate application to the cornea, 5 mg/ml bevacizumab eyedrop was administered twice daily for two weeks (n = 10). Group 3 (control): After silver nitrate application to the cornea, normal saline eyedrop was administered twice daily for two weeks (n = 10). Group 4 (vehicle): After silver nitrate application to the cornea, 1% DMSO eyedrop was administered twice daily for two weeks (n = 10). After two weeks from the silver nitrate application, corneas were evaluated by hand-held biomicroscope for their vascularization status. Then, corneas were excised and the expression levels of VEGFR-2, VEGF-A and the common miRNA markers for neovascularization (miR-15 b, miR-16, miR-23a, miR-126, miR-188, miR-210, miR-221, miR-222, miR-410 and miR-423) were evaluated by real-time PCR. Results: It was seen that the CNV was decreased in sunitinib- and bevacizumab-administered groups compared to the control and DMSO groups. Also, in comparison with the control group; VEGF-A expression was downregulated by nearly 0.75 times in sunitinib group and nearly 0.52 times in bevacizumab group. VEGFR-2 expression was downregulated by 0.89 times in sunitinib group and 0.68 times in bevacizumab group, compared to the control group. miR-15 b, miR-16 and miR-126 levels were statistically lower in sunitinib and bevacizumab groups, but miR-188 and miR-410 levels were two-fold higher compared to the control group. The miR-210 level was found higher only in sunitinib group compared to the control group. There were no statistically significant changes in miR-23a, miR-221, miR-222 and miR-423 levels among the groups. Conclusion: Topical application of bevacizumab (5 mg/ml) and sunitinib (0.5 mg/ml) decreases the levels of VEGFR-2 and VEGF-A in CNV. Further studies are needed for detailed analysis of genes which are targeted by up- or downregulated miRNAs in this study.

The effects of topical everolimus and sunitinib on corneal neovascularization

Abstract Purpose: To evaluate the effects of topical everolimus and sunitinib on corneal neovascularization (CNV). Methods: CNV was induced by application of silver nitrate to the cornea for all groups. Rats were divided into four groups of 10 rats each, and two corneas were obtained from each rat. Group I received 1 mg/ml everolimus, Group II received 0.5 mg/ml sunitinib, Group IV received no treatment (control group) and Group IV received 1% Dimethylsulfoxide (DMSO). All treatments were administrated twice daily for 2 weeks. The right corneas were used for extracellular signal-regulated kinase 1/2 (ERK 1/2) protein analysis by western blot analysis and the left corneas were used for ERK 1/2 and vascular endothelial growth factor-receptor (VEGFR-2) gene expression analysis by quantitative real-time PCR. Results: VEGFR-2 mRNA expression levels (ΔCt, median, min-max) were reduced in the everolimus 1.0 (0.25–1.81) and sunitinib 1.06 (0.24–2.68) treated groups compared with the control 4.74 (1.02–14.74) and DMSO groups 7.41 (0.72–13.10). The expression of ERK 1/2 protein and mRNA levels were reduced in everolimus group compared with the control group (p < 0.05). These differences were not seen between the sunitinib and control groups. Conclusıon: Topical administration of both everolimus and sunitinib reduced VEGFR-2 levels and inhibited CNV. In additon, everolimus reduced ERK 1/2 levels and seems to be more effective than sunitinib on CNV.

The effect of methimazole-induced postnatal hypothyroidism on the retinal maturation and on the Sirtuin 2 level

Abstract Purpose: To investigate the effect of methimazole-induced postnatal hypothyroidism on the retinal maturation and to study Sirtuin 2 (SIRT2) level in the hypothyroidic rat retina. Methods: Twenty newborn Wistar albino rat pups were used in this prospective, randomized study. Wistar albino rats, weight 250–300 g, were impregnated (without addition of any drug) and were fed normally. Rat pups were randomly divided into two groups and were fed with breast milk. After weaning till they were 90 days of age, rat pups received the same water as their lactating mothers drank. Group 1 (methimazole (MMI)-induced hypothyroidy group), rats were given MMI-water, whereas, in Group 2, normal tap water. When the pups were 90 days of age, 20 rat pups were decapitated and the eyes were isolated. Eyes were investigated using histological, histomorphometric and immunohistochemistrical techniques. Results: No histological difference was seen between the groups stained with hematoxylin and eosin. In both groups the retinal layer structures and cells were observed as normal. The examples in the groups had a normal distribution for retinal thickness (pixel) measure. The mean value (mean ± std. deviation) was 554.7 ± 228.4 in the control group and 494.7 ± 129.4 in the hypothyroidy group. There was no significance between the groups in terms of retinal thickness (p = 0.231). However, immunohistochemistry revealed that SIRT2 was weaker stained in the ganglion cell layer and visual cell layer in the hypothyroidy group compared to the control group. Conclusion: Postnatal hypothyroidism altered the retinal cytoarchitecture and layering which are regulated by thyroid hormones (THs) during retinal maturation in the postnatal period. THs may act by the induction of the SIRT family proteins or through their receptors. Postnatal screenings for THs levels are very important to provide normal retinal development.

Effect of experimentally induced hypothyroidism during gestation period on activity dependent neurotrophic factor (ADNF) in newborn rat brain tissue

Abstract Purpose The aim of the study was to evaluate the effects of prenatal hypothyroidism on neonatal rats by the way of activity-dependent neuroprotective factor (ADNF) expression. Methods Twenty-one Wistar albino neonatal rats were divided into two subgroups; a control group and neonatal rats with experimental maternal hypothyroidism. Hypothyroidism was induced by using propylthiouracil (PTU). Neonatal rats obtained PTU from breast milk continuously for 1 week after birth. The rats from the control group were fed only normal feed and water. After birth, body weight and blood thyroid hormone levels were tested. Glial fibrillary acidic protein (GFAP), Slug, Numb, Notch-1 and ADNF antibodies were used for immunohistochemical analysis. Real-time polymerase chain reaction (RT-PCR) and Western blotting analyses were used to evaluate ADNF gene expression levels from 1-week-old rat’s brain. Results There was no difference between the two groups for birth weights. The thyroxine (T4) level from the experimental group was <0.4 ng/mL, and it was 0.8 ng/mL for the control group. It was shown that, the results from the experimental group samples had significantly lower ADNF mRNA levels than control group (p < 0.05). The increase from GFAP and Numb expression and decrease from Slug expression were shown in the experimental group. Local differences were identified for ADNF and a decrease was shown in both sides of brain. There was no difference for Notch-1 expression for both groups. Conclusion In this study, decreasing ADNF expression might contribute to developing neurological problems in congenital hypothyroidism.

MicroRNA profiles in neuroblastoma: Differences in risk and histology groups†

To determine the miRNA expression profiles of neuroblastomas with different clinical and histological characteristics.

DNA Methyltransferase Expression and Proliferation Status of Metastatic Breast Cancer Cell Line After Prolonged and Repeated Rapamycin and Melatonin Application

Objective: The aim of this study was to investigate the effects of Rapamycin and Melatonin and their combination on deoxyribonucleic acid (DNA) methylation and cell proliferation in a estrogen receptor (ER)-negative breast cancer cell line (4T1 cell line). Materials and Methods: Four groups were designed with 4T1 cell line depending on drug combination (control, Rapamycin, Melatonin, Rapamycin + Melatonin) and their administration on different time periods (24, 48 and 72 hours). The drugs were administrated for 1, 2 and 3 times, respectively for these time periods. All samples were counted; immunostained (Ki67, DNA methyltransferase-1 (DNMT-1), DNA methyltransferase-3a (DNMT-3a) and p53) and real-time polymerase chain reaction (PCR) (DNMT-1 and DNMT-3a) was performed. Results: The live/dead cell ratios were decreased in the Rapamycin and Rapamycin + Melatonin applied groups. Ki67 immunostaining showed that there was a decreased proliferation in the drug applied groups at 48th hours compared to the 24th hours. Also DNMT-1 expressions were decreased at 72th hour compared to that at 24th hour in all groups, especially in the Rapamycin administrated group. Adversely, DNMT-3a expression was increased at 72th hour compared to that at 24th hour in the groups, especially in the Rapamycin administrated group. Furthermore, an increased expression of p53 was seen in the drug given groups (highest in the Rapamycin applied group) when the time prolonged. Real-time RT-PCR analysis of DNMT-1 gene expression showed a decreased expression level in the Melatonin given group compared to the control group and an increased expression level was seen in the Rapamycin and Rapamycin + Melatonin administrated groups compared to the control group. Conclusion: As a result, it was found that Rapamycin is more effective in metastatic breast cancer cells than Melatonin, both in the manner of cell viability and expressional changes of Ki67, DNMT-1, DNMT-3a and p53.

Corrigendum to “Melatonin ameliorates blood–brain barrier permeability, glutathione, and nitric oxide levels in the choroid plexus of the infantile rats with kaolin-induced hydrocephalus” [Brain Res. 1175 (2007) 117–125]

Mehmet Turgut⁎, Serpil Erdogan, Kemal Ergin, Mukadder Serter Department of Neurosurgery, Adnan Menderes University School of Medicine, TR-09100 Aydin, Turkey Department of Nuclear Medicine, Adnan Menderes University School of Medicine, TR-09100 Aydin, Turkey Department of Histology and Embryology, Adnan Menderes University School of Medicine, TR-09100 Aydin, Turkey Department of Biochemistry, Adnan Menderes University School of Medicine, TR-09100 Aydin, Turkey