Tuğba Kotil

Effects of systemic Thalidomide and intracerebroventricular Etanercept and Infliximab administration in a Streptozotocin induced dementia model in rats

Tumor necrosis factor-alpha (TNF-α) upregulation enhances amyloid β (Aβ) induced neurotoxicity in Alzheimers disease (AD). Intracerebroventricular streptozotocin (STZ) administration causes pathological changes and cognitive deficits similar to those seen in AD by causing impairment of brain glucose and energy metabolism. Recent reports indicate a protective role of Thalidomide, Etanercept, and Infliximab, all of which have anti-TNF-α activity, against cognitive and neuropathological changes in experimental and clinical studies. We aimed to investigate the protective effects of Thalidomide, Etanercept, and Infliximab in a rat model of intracerebroventricular STZ-induced dementia. Sprague-Dawley rats (250-300g) were separated to sham (n=6) and STZ (n=24) groups. The STZ group was divided into four groups (STZ, STZ-thalidomide, STZ-etanercept, and STZ-infliximab). Morriss water maze (MWM) and passive avoidance (PA) tests were performed. At the end of the third week, brain tissues were obtained. Histopathological analysis, immunohistochemistry, and electron microscopic examinations were done. The improvement performance of the STZ group was significantly reduced in the MWM test (p<0.001). Compared with the STZ, STZ-thalidomide, STZ-etanercept, and STZ-infliximab groups had significantly better performance (p<0.001, <0.05 and <0.05, respectively) in the MWM test. STZ administration caused a significant decrease in the mean escape latency in PA reflex (p<0.001). Thalidomide, Etanercept, and Infliximab were associated with better PA reflexes compared to the STZ group (p<0.001 for all). Morphological and immunohistochemical results showed increased neurodegenerative changes compared to sham group. Our findings are in line with the findings reported in the literature and encourage further studies with TNF-α antagonists, in particular Thalidomide.

The effects of permethrin on rat ovarian tissue morphology

All organisms are exposed to chemical agents during their lifetime. One of these agents is a pesticide that is used as fly killer. In this study we investigated the effects of permethrin on rat ovaries using light and electron microscopy. We used 24 Wistar albino female rats and divided them into 3 groups. Dosages 20 and 40 mg/kg/day permethrin were administered by gavage for 14 days. Normal saline was given to control rats. After treatment, ovarian tissues were collected and prepared for light and electron microscopy evaluation. Negative effects of permethrin were detected on follicular and corpus luteum cell morphology in a dose dependent manner when compared with the control group. Picnotic cellular appearance and condensed chromatin were detected as evidence of apoptotic cell death. Furthermore, degenerative changes were seen in the ultrastructure of mitochondria and endoplasmic reticulum. Thus, these findings suggested that permethrin caused degenerative effects on ovarian morphology in a dose dependent manner.

Severe neurodegenerative disease in brothers with homozygous mutation in POLR1A

In two brothers born to consanguineous parents, we identified an unusual neurological disease that manifested with ataxia, psychomotor retardation, cerebellar and cerebral atrophy, and leukodystrophy. Via linkage analysis and exome sequencing, we identified homozygous c.2801C>T (p.(Ser934Leu)) in POLR1A (encoding RPA194, largest subunit of RNA polymerase I) and c.511C>T (p.(Arg171Trp)) in OSBPL11 (encoding oxysterol-binding protein-like protein 11). Although in silico analysis, histopathologic evidence and functional verification indicated that both variants were deleterious, segregation with the patient phenotype established that the POLR1A defect underlies the disease, as a clinically unaffected sister also was homozygous for the OSBPL11 variant. Decreased nucleolar RPA194 was observed in the skin fibroblasts of only the affected brothers, whereas intracellular cholesterol accumulation was observed in the skin biopsies of the patients and the sister homozygous for the OSBPL11 variant. Our findings provide the first report showing a complex leukodystrophy associated with POLR1A. Variants in three other RNA polymerase subunits, POLR1C, POLR3A and POLR3B, are known to cause recessive leukodystrophy similar to the disease afflicting the present family but with a later onset. Of those, POLR1C is also implicated in a mandibulofacial dysostosis syndrome without leukodystrophy as POLR1A is. This syndrome is absent in the family we present.

Determination of DNA damage and telomerase activity in stanozolol-treated rats

Anabolic androgenic steroids (AAS) are performance-enhancing drugs commonly abused by atheletes. Stanozolol is a synthetic testosterone-derived anabolic steroid. Although it is well known that AAS have several side-effects, there are only few toxicological studies available on the toxic effects and mechanisms of action of stanozolol. The aim of this study was to investigate the genotoxic effects of stanozolol and to determine its effects on telomerase activity in Sprague-Dawley male rats. For this purpose, 34 male rats were divided into 5 groups as follows: i) the control group (n=5); ii) the propylene glycol (PG)-treated group (n=5); iii) the stanozolol-treated group (n=8); iv) the PG-treated group subjected to exercise (n=8); and v) the stanozolol-treated group subjected to exercise (n=8). PG is used as a solvent control in our study. Stanozolol (5 mg/kg) and PG (1 ml/kg) were injected subcutaneously 5 days/week for 28 days. After 28 days, the animals were sacrificed, and DNA damage evaluation (comet assay) and telomerase activity assays were then performed using peripheral blood mononuclear cells (PBMCs). Telomerase activity was measured by using the TeloTAGGG Telomerase PCR ELISA PLUS kit. The results of this study revealed that stanozolol treatment induced DNA damage, while exercise exerted a protective effect. Stanozolol treatment without exercise stimulation was associated with a significant increase in telomerase activity in the PBMCs.

The effects of titanium dioxide nanoparticles on ultrastructure of zebrafish testis (Danio rerio)

INTRODUCTION Nanotechnology investigates materials at nanoscale level (0.1-100nm in diameter). There are many commercially nanoproducts such as silver, silicon, titanium, zinc, and gold. They are used in a variety of applications and released to the environment. Titanium dioxide (TiO2) is one of the most commonly used nanoparticles (NP). In this study, the ultrastructural effects of TiO2-NP on zebrafish testis tissue were evaluated. MATERIAL AND METHOD Zebrafish were divided into four groups (N=60) as one control and 3 experimental groups (1mg/L, 2mg/L and 4mg/L TiO2). Testis tissues were dissected after 5days of the exposure. Tissues were fixed with 2.5% glutaraldehyde at 4°C. After routine electron microscopy tissue processing, the testis were embedded in epon resin. Ultrathin sections were counterstained with 1% uranyl acetate and lead citrate and examined using a transmission electron microscope. RESULTS Mitochodrial degeneration with swelling and cristae loss were detected in Sertoli cells and spermatogonial cells of TiO2-NP treated groups in a dose-dependent manner. Moreover, autophagic vacuole accumulation were seen in Sertoli cell cytoplasms of the experimental groups. Necrosis was also detected in the 4mg TiO2-NP-treated group. CONCLUSION TiO2-NP has been used in crop production, food additives, medicine, toothpastes, sunscreens, cosmetics, and in waste water treatment, which contaminated the environment. Our findings showed TiO2-NP-induced autophagy and necrosis at higher doses in Sertoli cells, which consequently negatively affected spermatogenic cells and testicular morphology of Zebrafish. It is important to give much more attention to the use of this NP to minimise the possible effects on nature and organisms.

Effects of stanozolol on apoptosis mechanisms and oxidative stress in rat cardiac tissue

HighlightsStanozolol increased PC and CAT levels, which is indirectly related with apoptosis.Stanozolol treatment was not associated with GSH, MDA and SOD parameters.Stanozolol induced mitochondrial apoptotic pathway.Exercise conditions have a preventive effect on cardiac apoptosis and oxidative stress. &NA; Stanozolol is a widely used 17&agr;‐alkylated anabolic androgenic steroid (AAS) derivative. Despite stanozolols adverse effects, its effect on oxidative stress parameters and mitochondrial apoptosis pathway is not clearly defined. In our study, thirty four male Sprague‐Dawley rats were divided into 5 groups as control (C), vehicle control (VC), steroid (ST), vehicle control‐exercise (VCE), and steroid‐exercise (STE). Animals were subcutaneously administered stanozolol 5 mg/kg in steroid groups and propylene glycol 1 ml/kg in the vehicle‐control groups. On the 28th day‐after sacrification, oxidative stress (MDA, GSH, PC, SOD, CAT) and apoptosis parameters (TUNEL, Cytochrome‐c) in cardiac tissue were evaluated. Also, blood vessel morphology of cardiac tissue was evaluated with Verhoeff‐van Giesen staining. It has been demonstrated that stanozolol administration triggers apoptosis by using TUNEL assay and cytochrome‐c immunohistochemical staining intensity, while this effect is significantly reduced in the presence of exercise. In conclusion, the present study demonstrated that stanozolol administration induces apoptosis with increasing PC and CAT levels, while GSH, MDA and SOD parameters do not reveal any significant change. Exercise has a protective role in stanozolol induced oxidative stress and apoptosis. According to Verhoeff–van Giesen staining results for blood vessel morphology assessment, it has been seen that exercise has a protective role on cardiac blood vessels. This mechanism needs further investigations with long term exposure studies for clarifying possible pathways.

Stanozolol administration combined with exercise leads to decreased telomerase activity possibly associated with liver aging

Anabolic agents are doping substances which are commonly used in sports. Stanozolol, a 17α-alkylated derivative of testosterone, has a widespread use among athletes and bodybuilders. Several medical and behavioral adverse effects are associated with anabolic androgenic steroids (AAS) abuse, while the liver remains the most well recognized target organ. In the present study, the hepatic effects of stanozolol administration in rats at high doses resembling those used for doping purposes were investigated, in the presence or absence of exercise. Stanozolol and its metabolites, 16-β-hydroxystanozolol and 3′-hydroxystanozolol, were detected in rat livers using liquid chromatography-mass spectrometry (LC-MS). Telomerase activity, which is involved in cellular aging and tumorigenesis, was detected by examining telomerase reverse transcriptase (TERT) and phosphatase and tensin homolog (PTEN) expression levels in the livers of stanozolol-treated rats. Stanozolol induced telomerase activity at the molecular level in the liver tissue of rats and exercise reversed this induction, reflecting possible premature liver tissue aging. PTEN gene expression in the rat livers was practically unaffected either by exercise or by stanozolol administration.

The effects of retinoic acid on mmp-2 production, proliferation and ultrastructural morphology in rat uterus

AIMS Retinoic acid (RA) has a vital importance in order to ensure continuity and morphology in many tissues. Matrix metalloproteinases (MMPs) have significant roles in proliferation, the formation of cancers, and metastasis. In this study the effects of RA on MMP-2 production in cells of rat uterus were investigated. METHODS Twenty-four adult Spraque Dawley rats were divided into two groups, the experimental group was treated with 40mg/kg/day 13-cis RA for 5days by gavage. Uterine tissue sections were treated with BrdU and MMP-2 antibodies, evaluated using light microscopy. Tissues were fixed with 2.5% glutaraldehyde and evaluated using transmission electron miroscopy. RESULTS MMP-2 immunoreactivity decreased in the stromal cells compared with the control group and no staining of MMP-2 was observed in glandular epithelium in the experimental group. BrDU labeling of cells showed significant decrease in RA-treated group versus control group cells. Based on the electron microscopy evaluation, the surface epithelial cells of the experimental group showed vacuolization, and an accumulation of lipofuscin bodies was also observed in the gland epithelium. Cells involving autophagic vacuoles contained excess lipid granules in the entire uterus layers especially localized at the border of the endometrium and myometrium. CONCLUSION RA had negative effects on cell proliferation and cell morphology and inhibited MMP-2 expression.