Sevil Cayli

Aquaporin-1 and Aquaporin-3 Expressions in the Intervertebral Disc of Rats with Aging

OBJECTIVE The intervertebral disc (IVD) undergoes biochemical and morphologic degenerative changes during the process of aging. Aquaporins (AQPs) are a family of water channel proteins that facilitate water and small solute movement in tissues and may have a potential role in the aging degeneration of IVDs. One of the important problems in understanding disc degeneration is to find cellular molecules which contribute to the pathogenesis of IVDs. XThe aim of this study was to demonstrate the expression of aquaporin 1 and 3 in nucleus pulposus (NP), annulus fibrosus (AF) cells of rat lumbar intervertebral discs from both young and aged animals using immunohistochemistry. MATERIAL AND METHODS Twenty Wistar-albino rats were included in the study. The rats were separated into two groups: 2-month-old rats (n=10) as the young group, 18-month-old rats (n=10) as the old group. The intervertebral disc tissues obtained from the lumbar spine (L1-L4, 4 discs) were used for immunohistochemical staining of AQP-1 and 3. RESULTS This study demonstrated that AQP-1 and AQP-3 immunoreactivity significantly decreased in NP and AF of aged rats compared to the young rats. CONCLUSION We suggest that AQP-1 and 3 may contribute to the age related degeneration of the intervertebral disc.

Age-related changes of aquaporin expression patterns in the postnatal rat retina

Previous studies revealed that the rat retina contains numerous membrane-located water channels, the aquaporins (AQPs). Protein expression patterns of AQP1-4, 6 and 9 were examined by immunohistochemistry. In the present study, we investigated the immunolocalization of AQP1-4, 6 and 9 during postnatal development in the rat retina and examined the effect of age on the tissue distribution of these channels. AQP1, 3, 4, 6 and 9 showed gradually increased expression in rat retinas from postnatal week 1 to week 12, and decreased in the 40-week-old rat retinas. AQP2 expression was barely seen in the first week in rat retinas and displayed a significant increase from week 1 to week 4, however no significant alteration of AQP2 was observed after 4weeks of development. AQP1 and 4 immunoreactivities were present in the inner limiting membrane (ILM), the ganglion cell layer (GCL), inner nuclear layer (INL) and retinal pigment epithelium (RPE) in the 4-, 12- and 40-week-old rat retinas. The RPE, OLM and ILM showed a remarkable expression of AQP1-4, 6 and 9 in the 4, 12 and 40-week-old rat retinas. The reduced expression of AQPs in aged rat retinas may indicate the involvement of AQPs in the pathogenesis of age-related retinal diseases.

The Pattern of Tyrosine Phosphorylation in Human Sperm in Response to Binding to Zona Pellucida or Hyaluronic Acid

In mammalian species, acquisition of sperm fertilization competence is dependent on the phenomenon of sperm capacitation. One of the key elements of capacitation is protein tyrosine phosphorylation (TP) in various sperm membrane regions. In previous studies performed, the pattern of TP was examined in human sperm bound to zona pellucida of oocytes. In the present comparative study, TP patterns upon sperm binding to the zona pellucida or hyaluronic acid (HA) were investigated in spermatozoa arising from the same semen samples. Tyrosine phosphorylation, visualized by immunofluorescence, was localized within the acrosomal cap, equatorial head region, neck, and the principal piece. Tyrosine phosphorylation has increased in a time-related manner as capacitation progressed, and the phosphorylation pattern was identical within the principal piece and neck, regardless of the sperm bound to the zona pellucida or HA. Thus, the data demonstrated that the patterns of sperm activation-related TP were similar regardless of the spermatozoa bound to zona pellucida or HA. Further, sperm with incomplete development, as detected by excess cytoplasmic retention, failed to exhibit TP.

The apoptotic effect of a high dose of toluene on liver tissue during the acute phase: an experimental study

The aim of this study is to investigate the acute toxic effects of high-dose toluene and its mechanisms on the liver tissue of toluene-treated rats. In this study, 16 adult male Wistar albino rats (200–220 g) were divided into two equal groups. Group I was used as a control group, while group II was exposed to high dose of toluene, 5200 mg/kg (6 ml/kg per gavage). After the 3-hour experimental period, blood samples and liver tissues were taken from the euthanized animals. Serum aspartate and alanine aminotransferase levels were assayed. Liver tissues were fixed in 10% neutral formalin, then embedded in paraffin and sectioned (5 μm thickness). Sections were stained with hematoxylin and eosin for histopathological examination. A terminal transferase dUTP nick end labeling assay was also done for the determination of apoptosis in liver tissues. For the determination of Bax and caspase-3 immunoreactivity, the sections were stained using avidin–biotin–peroxidase immunohistochemical method. The level of plasma transaminase was found to be increased in toluene administered rats. Additionally, slight degeneration of hepatocyte and mononuclear cell infiltration was observed in the liver tissue sections and a high (+++) immunoreactivity for Bax and caspase-3 protein was observed in the toluene group. This study showed that the high dose of toluene triggers apoptosis in the liver of rats via the mitochondrial pathway in acute period.

Central nervous system toxicity after acute oral formaldehyde exposure in rabbits: An experimental study

Formaldehyde (FA) is one of the most widely used chemical compounds in industrial field. It is described as toxic, particularly to the nervous system, the urogenital system, and the respiratory tracts. In this study, we determined the effects of acute oral exposure to FA in rabbit brain tissue. A total of 16 rabbits were selected and divided into 2 groups: formaldehyde group (group F) and control group (group C). FA was administered to group F at a rate of 40 mg/kg/day via a nasogastric tube for 5 days. Saline was similarly administered to the eight controls. All the animals were euthanized after 5 days of exposure, and brain tissue samples were collected in 10% neutral formalin and embedded in paraffin. To investigate the effects of FA on the apoptotic process, we examined active caspase-3, Bax, and Bcl-2 immunohistochemical expression and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate –biotin nick-end labeling (TUNEL) reactivity in the rabbit brains. In addition, glial fibrillary acidic protein (GFAP) was biochemically assessed in brain tissue samples for neurotoxicity. We found that FA treatment caused a significant decrease in Bcl-2 expression and an increase in active caspase-3 and Bax expressions as well as an increase in the number of TUNEL-positive apoptotic cells. The GFAP level was found to be significantly higher in group F. In conclusion, acute oral exposure to FA caused DNA damage, apoptosis, and neuronal injury in the rabbit brains.

Jab1 expression is associated with TGF-β1 signaling in chronic rhinosinusitis and nasal polyposis

Jab1, which is a fifth component of COP9 signalosome, plays an essential role in cell growth and proliferation. Jab1 is also shown to regulate transforming growth factor-beta (TGF-β) signaling in carcinoma cells. The aim of the present study was to investigate the expression and the correlation of Jab1 and TGF-β1 in chronic rhinosinusitis and nasal polyposis. Here, we show the elevated expression of Jab1 and TGF-β1 in diseased mucosa without nasal polyps and a correlation between Jab1 and TGF-β1 expression. Forty-six samples (26 patients with nasal polyps, 10 patients with chronic rhinosinusitis and 10 control subjects) were included to this study. Immunohistochemistry and Western blotting were performed for the assessment of Jab1 and TGF-β1 localization and the expression of proteins. Double staining of both proteins showed that Jab1 and TGF-β1 were colocalized in the epithelium, inflammatory cells and the vascular endothelium of nasal mucosa. There was a significant increase in the expression of TGF-β1 and Jab1 in patients without nasal polyps and a significant decrease in patients with nasal polyps compared to controls. Moreover, correlation was detected between the expression of Jab1 and TGF-β1 in chronic rhinosinusitis and nasal polyposis. Our results demonstrate that chronic rhinosinusitis is characterized by elevated expression of Jab1 and TGF-β1 compared to nasal polyposis and Jab1 may play a vital role in the pathogenesis of both chronic rhinosinusitis and nasal polyposis.

Increased Expression of Aquaporin-1 and Aquaporin-3 in Pterygium.

Purpose: Recent studies have shown that aquaporins (AQPs) play an important role in proliferating tumor microvessels and angiogenesis. In this study, the authors investigated the expression of aquaporin-1 (AQP1) and aquaporin-3 (AQP3) in pterygial and normal conjunctival tissues. Methods: Fifteen patients with pterygium were enrolled in the study. Pterygium was excised, and a conjunctival rotational flap or autograft was inserted. Normal conjunctival tissue was obtained from the flap or graft. Western blot analysis was performed to assess the expression of AQP1 and AQP3 in pterygial and normal conjunctival tissues. Tissue localization of AQP1 and AQP3 was determined by immunohistochemical analysis. Results: AQP1 and AQP3 are localized in the epithelial and subepithelial regions in pterygial and normal conjunctival tissues. Protein expression of both AQP1 and AQP3 was elevated in pterygia when compared with conjunctival tissues. The significant increase in protein expression of AQP1 was 3-fold in pterygium over normal conjunctiva (P = 0.004) and 2-fold increase in AQP3 expression of pterygium was detected (P = 0.02) according to densitometric analysis. Conclusions: Elevated protein expression of AQP1 and AQP3 was observed in pterygial tissues when compared with normal conjunctiva. The data suggest that the increased expression of AQP1 and AQP3 in pterygial tissues may be involved in the pathogenesis of pterygia, and therefore, AQP1 and AQP3 are potential therapeutic targets for preventing or delaying the progression of the disease.

Interaction Between Smad1 and p97/VCP in Rat Testis and Epididymis During the Postnatal Development

Members of the bone morphogenetic proteins (BMPs) superfamily are expressed in the testis and epididymis and are believed to have different biological functions during testicular and epididymal development. Smad1 is one of the signal transducers of BMP signaling and binds to several proteins involved in ubiquitin–proteasome system (UPS). Valosin-containing protein (p97/VCP) is required for the degradation of some UPS substrates. Although p97/VCP has been indicated in different cellular pathways, its association with BMP signaling in male reproductive system has not been elucidated. The aim of the present study was to investigate the cellular localization of Smad1, phospho-Smad1, and p97/VCP and the interaction of proteins in the postnatal rat testis and epididymis. Testicular and epididymal tissues from 5-, 15- and 60-day-old rats were examined by immunohistochemistry, immunofluorescence, Western blotting, and immunoprecipitation techniques. In 5-day-old rat testis, Smad1, phospho-Smad1, and p97/VCP were mainly expressed in gonocytes. In 15- and 60-day-old rat testis, proteins were overlapped in spermatogonia, Sertoli cells, and spermatocytes. Expression of proteins in the epithelial cells of epididymis was gradually increased from 5 to 15 days of age. Smad1 and phospho-Smad1 expressions showed uniformity in the different regions of epididymis, however p97/VCP immunoreactivity was higher only in caput epididymis compared to corpus and cauda epididymis in 15- and 60-day-old rat epididymis. Co-immunoprecipitation experiments further confirmed the Smad1-p97/VCP and p-Smad1-p97/VCP interactions. The overlap between Smad1 and p97/VCP expressions in the postnatal rat testis and epididymis suggests that p97/VCP may play important roles in mediating BMP signaling during spermatogenesis.

Developmental expression of p97/VCP (Valosin-containing protein) and Jab1/CSN5 in the rat testis and epididymis

BackgroundThe ubiquitin proteasome system (UPS) is a key player in regulating many cellular processes via proteasomal degradation of ubiquitinated proteins. Recently published data show that Jab1/CSN5 interacts with p97/VCP and controls the ubiquitination status of proteins bound to p97/VCP in mouse and human cells. However, coexpression of p97/VCP and Jab1/CSN5 in the developing rat testis and epididymis has not previously been studied.MethodsTesticular and epididymal tissues from 5-, 15-, 30-, and 60-day-old rats were examined by immunohistochemistry and Western blotting. Colocalisation of proteins was determined by immunofluorescence microscopy.ResultsIn the 5-day-old rat testis, p97/VCP and Jab1/CSN5 were specifically expressed in gonocytes. The expression of p97/VCP and Jab1/CSN5 significantly increased at day 15 and was found in spermatogonia, Sertoli cells and spermatocytes. In 30- and 60-day-old rat testes, p97/VCP indicated moderate to strong expression in Sertoli cells, spermatogonia, round and elongating spermatids. However, moderate to weak expression was observed in spermatocytes. Jab1/CSN5 showed strong expression in spermatogonia and spermatocytes, while relatively moderate expression was observed in round and elongating spermatids in 30- and 60-day-old rat testes. In contrast, in the epididymis, the expression of both proteins gradually increased from 5 to 60 days of age. After rats reached 2 weeks of age, the expression of both proteins was mostly restricted to the basal and principal cells of the caput epididymis.ConclusionsOur study suggests that p97/VCP and Jab1/CSN5 could be an important part of the UPS in the developing rat testis and epididymis and that both proteins may be involved in the regulation of spermatogenesis and epididymal epithelial functions.

Evaluation of effects of repeated sevoflurane exposure on rat testicular tissue and reproductive hormones

Abstract Context: Evaluation of inhalation anesthetics on sperm and reproductive hormones are extremely important. Objective: Investigation of the effects of sevoflurane used as an inhalation anesthetic on sperm morphology and reproductive hormones in rat testes. Materials and methods: Forty Wistar-Albino male rats were divided into five groups of eight rats each. The control group received 2 L/min oxygen for seven days, 2 h/day while sevoflurane treatment S1 received 1 minimal alveolar concentration (MAC) sevoflurane + 2 L/min oxygen for seven days, 2 h/day, and sevoflurane S2 received 1 MAC sevoflurane + 2 L/min oxygen for seven days, 2 h/day followed by seven days of no treatment. Sevoflurane treatment S3 received 1 MAC sevoflurane + 2 L/min oxygen for 14 days, 2 h/day and sevoflurane treatment S4 received 1 MAC sevoflurane + 2 L/min oxygen for 14 days, 2 h/day, with no treatment for the following seven days. All rats were examined histologically after experimental procedures. Rat luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), and inhibin levels were measured. Results: Histological injury scores were significantly higher in S2, S3, and S4 receiving sevoflurane in comparison to the control group (p = 0.001, <0.001, and 0.001, respectively). Sperm motility and concentration decreased in S3 and S4 compared to the control group (p = 0.03 and 0.02, respectively). Significant differences were detected among all groups for serum LH, FSH, T, and inhibin serum concentrations (p < 0.05). Conclusion: Testicular and sperm morphology, and reproductive hormones were affected by chronic exposure to sevoflurane. However, more randomized, controlled, and well-designed clinical studies with larger population are needed to confirm of these results.