Browsing by Author "Helvacioglu, Fatma"

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Adipose-Derived Stem Cells Enhance Axonal Regeneration through Cross-Facial Nerve Grafting in a Rat Model of Facial Paralysis
(2016) Abbas, Ozan L.; Borman, Huseyin; Uysal, Cagri A.; Gonen, Zeynep B.; Aydin, Leyla; Helvacioglu, Fatma; Ilhan, Sebnem; Yazici, Ayse C.; https://orcid.org/0000-0001-6236-0050; https://orcid.org/0000-0002-6026-0045; https://orcid.org/0000-0002-3132-242X; 27465163; AAJ-2949-2021; AAH-8887-2021; AAS-6810-2021
Background: Cross-face nerve grafting combined with functional muscle transplantation has become the standard in reconstructing an emotionally controlled smile in complete irreversible facial palsy. However, the efficacy of this procedure depends on the ability of regenerating axons to breach two nerve coaptations and reinnervate endplates in denervated muscle. The current study tested the hypothesis that adipose-derived stem cells would enhance axonal regeneration through a cross-facial nerve graft and thereby enhance recovery of the facial nerve function. Methods: Twelve rats underwent transection of the right facial nerve, and cross-facial nerve grafting using the sciatic nerve as an interpositional graft, with coaptations to the ipsilateral and contralateral buccal branches, was carried out. Rats were divided equally into two groups: a grafted but nontreated control group and a grafted and adipose-derived stem cell-treated group. Three months after surgery, biometric and electrophysiologic assessments of vibrissae movements were performed. Histologically, the spectra of fiber density, myelin sheath thickness, fiber diameter, and g ratio of the nerve were analyzed. Immunohistochemical staining was performed for the evaluation of acetylcholine in the neuromuscular junctions. Results: The data from the biometric and electrophysiologic analysis of vibrissae movements, immunohistochemical analysis, and histologic assessment of the nerve showed that adipose-derived stem cells significantly enhanced axonal regeneration through the graft. Conclusion: These observations suggest that adipose-derived stem cells could be a clinically translatable route toward new methods to enhance recovery after cross-facial nerve grafting.
Antiproliferative and Mitochondrial Protective Effects of Apigenin in an Oxygen-Induced Retinopathy In Vivo Mouse Model
(2021) Sezenoz, Almila Sarigul; Akkoyun, Imren; Helvacioglu, Fatma; Haberal, Nihan; Dagdeviren, Attila; Bacanli, Didem; Yilmaz, Gursel; Oto, Sibel; 0000-0002-2860-7424; 34665015; AAK-7713-2021
Purpose: To investigate the effects of a common dietary flavonoid apigenin on retinal endothelial cell proliferation, retinal morphological structure, and apoptotic cell death in an oxygen-induced retinopathy (OIR) mouse model to evaluate the possibility of the use of apigenin in the treatment of ocular neovascular diseases (ONDs). Methods: Ninety-six newborn C57BL/6J mice were included. Eight groups were randomized, each including 12 mice. Two negative control groups were kept in room air: the first without any injection and the second received intravitreal (IV) dimethyl sulfoxide (DMSO), which is the solvent we used. The OIR groups were exposed to 75% +/- 2% oxygen from postnatal days (PD) 7 to 12. On PD 12, the mice were randomly assigned to 6 groups: 2 OIR control groups (1 received no injection, 1 received IV-DMSO), 2 IV-apigenin groups (10 and 20 mu g/mL), and 2 intraperitoneal (IP)-apigenin groups (10 and 20 mg/kg). We quantified retinal endothelial cell proliferation by counting neovascular tufts in cross-sections and examined histological and ultrastructural changes through light and electron microscopy. We evaluated apoptosis by terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL). Results: We detected a significant increase in endothelial cell proliferation in the OIR groups. Groups receiving apigenin, both IP and IV, had significant decreases in endothelial cells, atypical mitochondrion count, and apoptotic cells compared with the groups receiving no injections. None of the apigenin-injected groups revealed cystic degeneration or cell loss. Conclusions: Apigenin suppresses neovascularization, has antiapoptotic and antioxidative effects in an OIR mouse model, and can be considered a promising agent for treating OND. Clinical trial (Project number: DA15/19).
Comparative effects of photobiomodulation therapy at wavelengths of 660 and 808 nm on regeneration of inferior alveolar nerve in rats following crush injury
(2020) Diker, Nurettin; Aytac, Duygu; Helvacioglu, Fatma; Oguz, Yener; 0000-0002-6026-0045; 31273571; AAH-8887-2021
The aim of the present study was to investigate the therapeutic effects of 660-nm and 880-nm photobiomodulation therapy (PBMT) following inferior alveolar nerve (IAN) crush injury. Following the nerve crush injuries of IAN, 36 Wistar rats were randomly divided into three groups as follows: (1) control, (2) 660-nm PBMT, and (3) 808-nm PBMT (GaAlAs laser, 100 J/cm(2), 70 mW, 0.028-cm(2) beam). PBMT was started immediately after surgery and performed once every 3 days during the postoperative period. At the end of the 30-day treatment period, histopathological and histomorphometric evaluations of tissue sections were made under a light and electron microscope. The ratio of the inner axonal diameter to the total outer axonal diameter (g-ratio) and the number of axons per square micrometer were evaluated. In the 808-nm PBMT group, the number of nerve fibers with suboptimal g-ratio ranges of 0-0.49 (p < 0.001) is significantly lower than expected, which indicates better rate of myelinization in the 808-nm PBMT group. The number of axons per square micrometer was significantly higher in the 808-nm PBMT group when compared with the control (p < 0.001) and 660-nm PBMT group (p = 0.010). The data and the histopathological investigations suggest that the PBMT with the 808-nm wavelength along with its settings was able to enhance IAN regeneration after nerve crush injury.
Comparative Evaluation of the Electrophysiological, Functional and Ultrastructural Effects of Alpha Lipoic Acid and Cyanocobalamin Administration in A Rat Model of Sciatic Nerve Injury
(2017) Horasanli, Bahriye; Hasturk, Askin Esen; Arikan, Murat; Togral, Guray; Helvacioglu, Fatma; Dagdeviren, Atilla; Mut, Senem; Harman, Ferhat; Argun, Guldeniz; https://orcid.org/0000-0003-3142-1011; https://orcid.org/0000-0002-6026-0045; 28968230; AAH-8887-2021; AES-7155-2022
BACKGROUND: Vitamin B12 and alpha lipoic acid (ALA) are known to promote functional and morphological recovery after peripheral nerve injury. OBJECTIVE: To compare the regenerative and neuroprotective effects of vitamin B12 and ALA treatment after sciatic nerve injury. METHODS: A total of 40 rats were randomly assigned to control (sciatic nerve exposure without injury or anastomosis), sham (sciatic nerve injury and epineural anastomosis were performed but no treatment was administered), PS (isotonic saline was administered for 12 weeks after surgery), ALA (2 mg/kg ALA was administered for 12 weeks after surgery), and vitamin B12 groups (2 mg/kg cyanocobalamin was administered for 12 weeks after surgery). Functional recovery was determined by footprint analysis, in vivo neurophysiology, and ex vivo histopathological examination. RESULTS: ALA treatment produced significant improvements in sciatic functional index values and non-significant improvements on electroneuromyography compared to vitamin B12 treatment. Upon histopathological examination, the regenerative effects of ALA were relevant to axonal structural recovery whereas vitamin B12 produced greater improvements in edema and myelination. CONCLUSIONS: While both vitamin B12 and ALA produced improvements after sciatic nerve injury, ALA was more functionally effective. The unique ultrastructural effects of vitamin B12 and ALA treatment should be considered in future studies.
Comparison of the Efficacy of Cabergoline and Bromocriptine in a Rat Model of Ovarian Hyperstimulation Syndrome
(2018) Coban, Pinar Gulsen; Oruc, Ayla Sargin; Ozaksit, M. Gulnur; Demirtas, Aysegul; Helvacioglu, Fatma; Fidan, Pinar Ayran; Sirvan, Levent; Eroglu, Semra; https://orcid.org/0000-0002-6026-0045; AAH-8887-2021; AAD-8353-2020
OBJECTIVE: To compare cabergoline and bromocriptine for their effectiveness in ovarian hyperstimulation syndrome (OHSS) and their impact on endometrial receptivity in a rat model. STUDY DESIGN: A total of 25 immature Wistar female rats were randomly assigned to 5 groups: group 1 (control), group 2 (hyperstimulated), group 3 (cabergoline), group 4 (2 mg/kg bromocriptine), and group 5 (4 mg/kg bromocriptine). Body-ovarian weights, the number of corpora lutea, and endometrial receptivity were investigated. RESULTS: Cabergoline appeared to be less effective in reduction in body weight (p = 0.042). Ovarian weight was significantly reduced by a higher dose of bromocriptine (p<0.000). The number of corpora lutea were similar. In the cabergoline group, endometrial pinopode expression was reduced. In the bromocriptine groups the presence of pinopode formation was not affected, whereas some of those displayed different structural features like dome or racket shaped of yet undetermined significance. CONCLUSION: According to our findings, bromocriptine, particularly in higher doses, might be preferred with regard to ovarian mass suppression, weight gain, and pinopode expression. Further studies assessing the efficacy and safety of different doses of bromocriptine administration in OHSS followed by clinical trials about implantation and pregnancy rates are required.
Does Ginkgo biloba Protect Developing Testes from Chronic Hypobaric Hypoxia?
(2017) Gul, Elif Ensari; Kaplanoglu, Gulnur Take; Helvacioglu, Fatma; Kaplanoglu, Iskender; Seymen, Cemile Merve; 0000-0002-6026-0045; 0000-0002-8945-3801; AAH-8887-2021; AAS-5415-2021
OBJECTIVE: To evaluate the potential protective effects of Ginkgo biloba on developing testes exposed to chronic hypobaric hypoxia during their prenatal life. STUDY DESIGN: Twelve pregnant Wistar albino rats on the fifth gestational day were placed in hypoxic chambers for the upcoming 15 days. Six pregnant female rats were kept under normal atmospheric conditions during the pregnancy as a control group. The study groups were as follows: Control, Hypoxia, and Hypoxia + Ginkgo biloba. Ginkgo biloba was administered for each designated postnatal sacrifice day. For the Hypoxia + Ginkgo biloba group, after birth, 100 mg/kg of Ginkgo biloba extract was administrated orally to the newborn male rats. Testes tissues were sampled on postnatal days 7, 14, and 21 from each group, and PCNA, TUNEL, and TEM examinations were performed. RESULTS: PCNA immunoreactivity was decreased and TUNEL positive cell number was increased in the hypoxic group. TEM examination revealed degenerative changes in hypoxic group testes tissue. Hypoxia changed the cell cycle in spermatogenic series by reducing proliferation and increasing apoptosis. Spermatogenic cell degeneration and high Leydig cell activity were determined in the hypoxia group by TEM examinations. CONCLUSION: We believe that Ginkgo biloba has protective effects on testes tissue, especially in long-term use.
Effect of Acrylamide Treatment on Arginase Activities and Nitric Oxide Levels in Rat Liver and Kidney
(2014) Ozturan-Ozer, Eda; Ucar, Gulberk; Helvacioglu, Fatma; Akaydin-Aldemir, Derya; Turkoglu, Suna; https://orcid.org/0000-0001-6543-4043; https://orcid.org/0000-0002-6026-0045; https://orcid.org/0000-0003-4805-1918; AAK-3000-2021; AAH-8887-2021; AAJ-2243-2021
Aim: To evaluate the effects of acrylamide treatment on the activities of rat liver, kidney arginase activities and nitric oxide levels considering the possible induction of oxidative stress. Materials and methods: Serum aminotransferase activities, blood-urea nitrogen (BUN) and creatinine concentrations and tissue malondialdehyde (MDA), reduced glutathione (GSH), total nitrite concentrations and arginase activities were evaluated in groups. Histopathological analysis was performed. Results: Acrylamide treatment did not modulate liver and kidney serum markers. Hepatic MDA, GSH concentrations did not change whereas they were elevated in kidney tissues of high dose treated group (p<0.05). Arginase activity in grain liver tissue decreased (p<0.0001), but specific activity did not alter. Total nitrite concentrations increased in high dose treated group (p<0.05). In kidney, high dose of acrylamide treatment elevated activity and specific activity of arginase (p<0.05). No alteration was detected in total nitrite levels. Ultrastructural alterations were detected in epithelial cells of proximal tubules in kidney sections of the rats treated with high dose of aculamide. Conclusion: Liver seems to protect itself against acrylamide toxicity whereas, kidney can be considered as a probable target tissue for acrylamide-induced oxidative stress.
Effect of Creatine on Rat Sciatic Nerve Injury: A Comparative Ultrastructural Study
(2018) Helvacioglu, Fatma; Kandemir, Ersin; Karabacak, Busra; Karatas, Idil; Pecen, Ahmet; Ercan, Ipek; Sencelikel, Tugce; Dagdeviren, Attila; 0000-0002-6048-3951; 0000-0002-6026-0045; 0000-0001-8990-8282; 27858383; AAI-6791-2021; AAH-8887-2021; P-2877-2014
AIM: Creatine is an endogenous molecule synthesized in the liver, kidney and pancreas from glycine and arginine and is important for mitochondrial metabolism. It is widely used as a supplement for improving muscle mass and function for many years. As it is expected to prevent apoptosis and diminish oxidative stress, it is also studied in a number of neurodegenerative diseases for its beneficial effect in recent years. We studied the effect of creatine on the peripheral nerve injury in an experimental rat crush injury model to obtain ultrastructural evidence. MATERIAL and METHODS: Animals were randomly divided into 3 groups having 5 animals in each group. Group 1 was the control group, Group 2 the trauma group and Group 3 the trauma+ creatine group. The first group served as sham control. In group 2 and group 3, sciatic nerves of the rats received crush injury using aneurysm clips. In group 3, daily 2 g/kg creatine monohydrate was administered via gavage after the trauma. Nerve samples were obtained at the 28th day after trauma for light and electron microscopic evaluation. RESULTS: Our comparative analysis results suggest a possible positive effect of creatine supplement on peripheral nerve regeneration as statistical analysis revealed significant differences between group 2 and group 3. Though our finding does not represent a miracle of regenerative support, beneficial usage of creatine is documented in the present study. CONCLUSION: Creatine supplement helps to diminish the harmful effects of peripheral nerve crush injury which is also supported by electron microscopy findings.
Effect of intravitreal and intraperitoneal cyanidin-3-glucoside injection in oxygen-induced retinopathy mouse model
(2019) Ercan, Zeynep E.; Haberal, Nihan; Helvacioglu, Fatma; Dagdeviren, Atilla; Yİlmaz, Gursel; 0000-0002-9915-3781; 31124490; AAQ-3136-2020
Purpose: To evaluate the effect of cyanidin-3-glucoside (C3G) in oxygen-induced retinopathy (OIR) mouse model. Methods: In this experimental study, 10 C57BL / 6J type mice exposed to room air comprised two control groups (n = 5 each; a negative control and a group receiving intravitreal sterile dimethyl sulfoxide [IVS DMSO]). Thirty C57BL / 6J type mice exposed to 75% +/- 2% oxygen from postnatal day 7 to postnatal day 12 comprised the OIR groups. On postnatal day 12, these mice were randomized into six groups (n = 5 each): two OIR control groups (negative control and IVS DMSO), two intravitreal C3G groups (300 and 600 ng/mu L), and two intraperitoneal C3G groups (0.05 and 0.1 mg/kg). We quantified neovascularization by counting endothelial cell proliferation on the vitreal side of the inner limiting membrane of the retina and examined histological and ultrastructural changes via light and electron microscopy and apoptosis by terminal deoxynucleotidyl transferase deoxy-UTP-nick end labeling. Results: The intravitreal C3G groups yielded lower endothelial cell counts compared with the intravitreal DMSO group. The intraperitoneal high-dose group had lower cell counts compared with the OIR control groups. Electron microscopy revealed significantly less mitochondrial dysmorphology in intravitreal groups and the high-dose intraperitoneal mice. We noted no difference in apoptotic cell count between the controls, low-dose intravitreal, and both intraperitoneal groups. However, apoptotic cell count was significantly higher in the high-dose intravitreal group. Conclusion: C3G suppresses endothelial cell proliferation in an OIR mouse model, leads to a reduced hyperoxia-induced mitochondrial dysmorphology, but increases apoptotic cell death in high concentrations.
The effect of systemic rifampicin treatment on inferior alveolar nerve regeneration in rats following crush injury
(2020) Diker, Nurettin; Caglayan, Berrak; Helvacioglu, Fatma; Kilic, Ertugrul; 0000-0002-6026-0045; 32236990; AAH-8887-2021
Axonal regeneration of the inferior alveolar nerve (IAN) is a therapeutic target for functional recovery after peripheral nerve injury. Rifampicin exerts anti-apoptotic, anti-inflammatory, and anti-oxidant effects on nerve tissues that may enhance functional recovery after peripheral nerve injury. The aim of the present study was to evaluate the therapeutic effects of systemic rifampicin following IAN crush injury. Following the nerve crush injuries of the IAN, 24 Sprague-Dawley rats were randomly divided into three groups to receive daily intraperitoneal injections of either vehicle, 5 mg kg(-1) rifampicin, or 20 mg kg(-1) rifampicin. Twenty-four days after induction of nerve injuries, Fluorogold (FG) was injected over the mental foramen for the evaluation of neuronal survival. At the end of the four-week period, histologic and histomorphometric examination of IAN samples were performed and FG positive cells were counted in the trigeminal ganglion sections. FG positive cells were significantly more frequent in the 20 and 5 mg kg(-1) rifampicin groups than in the vehicle-treated group. Electron microscopic analyses revealed that the percentage of axons with optimum g-ratio was significantly lower in the vehicle group than in both treatment groups. In conclusion, systemic rifampicin treatment can enhance peripheral nerve regeneration.
Effects of Platelet-Rich Fibrin Membrane on Sciatic Nerve Regeneration
(2018) Bayram, Burak; Akdeniz, Sidika Sinem; Diker, Nurettin; Helvacioglu, Fatma; Erdem, Saban Remzi; 0000-0002-7825-1083; 0000-0002-6026-0045; 0000-0002-7537-2170; 29381631; AAS-4519-2020; AAH-8887-2021; AAJ-2370-2021
Alternative treatment approaches to improve the regeneration capacity of damaged peripheral nerves are currently under investigation. The objective of the present study was to evaluate the effects of platelet-rich fibrin (PRF) membrane after sciatic nerve crush injury in rabbits by histomorphometric and electromyographic analysis. The left sciatic nerves of 20 male Vienna rabbits were clamped for 30seconds to induce crush injuries. Animals were randomly divided into 2 groups: PRF and control. For each animal in the PRF group, a PRF membrane was wrapped around the injured part of the sciatic nerve to form a tube. No additional treatment was performed in the control group. After a 12-week healing period, tissue samples from the injured nerve region were harvested and the g-ratio of axons, axon density, and impulse transmission changes were evaluated. Analysis revealed that axon density differences were not statistically significant between groups (P=0.139). The rate of nerve fibers with optimum g-ratio was significantly lower in the PRF group than in the control group (P=0.02). Conduction velocity differences between groups were not statistically significant. Although PRF application has previously shown positive regeneration effects on maxillofacial tissues, local PRF membrane application in tube form did not show any histomorphometric or functional improvement in peripheral nerve crush injury recovery.
Effects of topical Coenzyme Q10, Xanthan Gum and Sodium Hyaluronate on corneal epithelial wound healing
(2021) Asena, Leyla; Gokgoz, Gulsah; Helvacioglu, Fatma; Ozgun, Gonca; Deniz, Emine Ebru; Altinors, Dilek Dursun; 0000-0002-6848-203X; 0000-0002-4837-7937; 0000-0002-6026-0045; 34134604; E-5914-2016; AAY-7932-2021; AAH-8887-2021
Background: The aim was to compare the effects of three different eye drops on corneal epithelial wound healing in an experimental model. Methods: Twenty-four eyes of 24 female BALB/c mice were included. A 2 mm central corneal epithelial defect was created. Topical Coenzyme Q10 + Vitamin E D-alpha-TPGS 4 x 1 was applied to Group A (n = 6), topical Sodium hyaluronate + Xanthan Gum + 0.3% Nethylmicine 4 x 1 to Group B (n = 6) and topical Sodium hyaluronate 4 x 1 to Group C (n = 6). Group D (n = 6) was the control group without treatment. Clinical scoring according to corneal fluorescein staining and histopathological evaluations was performed. Results: Clinical scores according to corneal fluorescein staining were similar in all groups on days 1 (p = 0.05), 2 (p = 0.15) and 3 (p = 0.62). Electron microscopy revealed disruption of intercellular junctions between corneal epithelial cells and intracellular vacuole formation in all groups except Group A. Corneal epithelial thickness and superficial epithelial microvillus arrangement were close to normal in Group A. Conclusion: Although there was no difference in clinical scores between groups, electron microscopy revealed a better organised epithelium with normal configuration of microvilli and less vacuolisation in Group A
Evaluation of the Effects of Low-Level Laser Therapy on Diabetic Bone Healing
(2019) Diker, Nurettin; Aytac, Duygu; Helvacioglu, Fatma; Dagdelen, Cansu; Oguz, Yener; 31232987
The aim of the present study was to evaluate the effects of low-level laser therapy (LLLT) and biphasic alloplastic bone graft material on diabetic bone healing. Induction of diabetes was performed in 14 male Sprague-Dawley rats by intraperitoneal injection of a 50 mg/kg dose of streptozotocin. Two bilaterally symmetrical non-critical-sized bone defects were created in the parietal bones in each rat. Right defects were filled with biphasic alloplastic bone graft. Rats were randomly divided into 2 groups, with 1 group receiving 10 sessions of LLLT (GaAlAs, 78.5 J/cm(2), 100mW, 0.028 cm(2) beam). The LLLT was started immediately after surgery and once every 3 days during postoperative period. At the end of treatment period, new bone formation and osteoblast density were determined using histomorphometry. Empty (control), graftfilled, LLLT-treated and both graft-filled and LLLT-treated bone defects were compared. New bone formation was higher in the graft treatment samples compared with the control (P = 0.009) and laser samples (P = 0.029). In addition, graft-laser combination treatment samples revealed higher bone formation than control (P = 0.008) and laser (P = 0.026) samples. Osteoblast density was significantly higher in the laser treatment (P < 0.001), graft treatment (P = 0.001) and graft-laser combination treatment (P < 0.001) samples than control samples. In addition, significantly higher osteoblast density was observed in the graft-laser combination treatment samples compared to the graft treatment samples (P = 0.005). The LLLT was effective to stimulate osteoblastogenesis but failed to increase bone formation. Graft augmentation for treatment of bone defects seems essential for proper bone healing in diabetes, regeneration may be supported by the LLLT to enhance osteoblastogenesis.
Histomorphometric and Ultrastructural Evaluation of Long-Term Alpha Lipoic Acid and Vitamin B12 Use After Experimental Sciatic Nerve Injury in Rats
(2016) Arikan, Murat; Togral, Guray; Hasturk, Askin Esen; Horasanli, Bahriye; Helvacioglu, Fatma; Dagdeviren, Atilla; Tekindal, Mustafa Agah; Parpucu, Murat; 0000-0002-6026-0045; 0000-0002-4060-7048; 0000-0003-0376-5589; 0000-0003-3142-1011; 27476916; AAH-8887-2021; AAE-5065-2019; U-9270-2018; S-4175-2018
AIM: To analyze the therapeutic effects of long-term alpha lipoic acid (A-LA) and vitamin B12 use via histomorphometric methods and electron microscopy in the transected sciatic nerves of rats. MATERIAL and METHODS: Forty rats were randomized into five groups (n=8/group). In group I, 1 cm segment of sciatic nerve was resected without any other intervention. In group II (sham), following right sciatic nerve transection, primary epineurial anastomosis was performed by placing the edges of the nerve end-to-end. In group III (saline), after right sciatic nerve transection, the ends of the nerves were brought together and closed after application of intraperitoneal physiologic saline. In group IV, 2 mg/kg of alpha lipoic acid and in group V, 2 mg/kg of vitamin B12 was administered intraperitoneally before surgical intervention. RESULTS: Histomorphometric and electron microscopic analyses revealed that vitamin 312 did not prevent structural changes, abnormal myelination and g-ratio deviations regarding the functional aspects of the sciatic nerve. Alpha lipoic acid was more effective in restructuring the histomorphometric and structural aspects of the nerve with more myelinated fibers with optimal values (0.55-0.68) than vitamin B12 groups, in which the number of myelinated nerve fibers significantly decreased at optimal intervals (0.55-0.68). CONCLUSION: A-LA administration following peripheral nerve transection injury is more effective in promoting nerve healing regarding the structural aspects of the sciatic nerve compared to vitamin B12 and also myelination of nerve fibers by increasing g-values.
Intussusceptive Growth of Vascular Bed in Human Placenta
(2019) Fidan, Pinar Ayran; Helvacioglu, Fatma; Dagdeviren, Atilla; 0000-0003-3047-0305; ABG-5365-2020
Objective: Normal embryonic and fetal development is strictly bound to maternal health and functioning placenta. Besides the invasion and differentiation of trophoblastic cell lineage; development of effective vasculature is crucial for the function of placenta. Placental vessels first arise by vasculogenesis in early development of villi and then succeeded by angiogenesis during fetal life. In the recent decades a new form of angiogenesis, "intussusceptive angiogenesis", besides classical sprouting angiogenesis is well documented. The presence of intussusception was shown at multiple organs but in placenta, in recent literature. We aimed to determine whether intussusceptive angiogenesis is present in human placenta to obtain further evidence on the development of vascular bed. Methods: The term placenta samples were obtained from 10 healthy pregnancies following caesarean sections. Tissues were processed using routine plastic embedding technique; thin sections were contrasted with uranyl acetate & lead citrate; observed and photographed by transmission electron microscope. Results: Our examinations revealed that both sprouting and intussusceptive angiogenesis is present in floating villi of term placenta. Phases of intussusception were documented in various samples. Conclusion: The presence of intussusceptive angiogenesis will help our understanding of microvascular bed remodeling during pregnancy. We believe that this new finding will help us to determine the relation of microvascular bed development in normal and abnormal placentas.
Prostaglandin F receptor expression in intrauterine tissues of pregnant rats
(2014) Anadol, Elvan; Kanca, Halit; Yar, Atiye Seda; Helvacioglu, Fatma; Menevse, Sevda; Calguner, Engin; Erdogan, Deniz
In this investigation, we studied the expression and localization of rat prostaglandin F (FP) receptor in uterine tissues of rats on gestational Days 10, 15, 18, 20, 21, 21.5 and postpartal Days 1 and 3 using Western blotting analysis, real-time PCR, and immunohistochemistry. A high level of immunoreactivity was observed on gestational Days 20, 21, and 21.5 with the most significant signals found on Day 20. FP receptor protein was expressed starting on gestational Day 15, and a fluctuating unsteady increase was observed until delivery. Uterine FP receptor mRNA levels were low between Days 10 and 18 of gestation (p < 0.05). The transcript level increased significantly on Day 20 and peaked on Day 21.5 just before labor (p < 0.05). There was a positive correlation between FP receptor mRNA expression and serum estradiol levels (rs = 0.78; p < 0.01) along with serum estradiol/progesterone ratios (rs = 0.79; p < 0.01). In summary, we observed an increase FP receptor expression in rat uterus with advancing gestation, a marked elevation of expression at term, and a concominant decrease during the postpartum period. These findings indicate a role for uterine FP receptors in the mediation of uterine contractility at term.
Role of autophagy and evaluation the effects of microRNAs 214, 132, 34c and prorenin receptor in a rat model of focal segmental glomerulosclerosis
(2021) Yildirim, Derya; Bender, Onur; Karagoz, Zehra Firat; Helvacioglu, Fatma; Bilgic, Mukadder Ayse; Akcay, Ali; Ruzgaresen, Nuket Bavbek; 0000-0002-6026-0045; 34087284
Aims: Focal segmental glomerulosclerosis (FSGS) is the common cause of chronic renal disease worldwide. Although there are many etiologic factors which have common theme of podocyte injury conclusive etiology is not clearly understood. In this study, we aimed to explore the role of autophagy in the pathogenesis of podocyte injury, which is the key point in disease progression, and the roles of intrarenal microRNAs and the prorenin receptor (PRR) in the 5/6 nephrectomy and adriamycin nephropathy models of FSGS. Main methods: For experimental FSGS model, 5/6 nephrectomy and adriamycin nephropathy models were created and characterized in adult Sprague Dawley rats. Microarray analysis was performed on FSGS and control groups that was confirmed by q-RT-PCR. Beclin1, LC3B, PRR, ATG7 and ATG5 expression were evaluated by western blotting and immunohistochemistry. Also, Beclin1 and PRR expression were measured by ELISA. Glomerular podocyte isolation was performed and autophagic activity was evaluated in podocytes before and after transfection with miRNA mimic and antagonists. Key findings: Glomerular expression of Beclin1, LC3B, PRR, ATG7 and ATG5 were significantly lower in the 5/6 nephrectomy than adriamycin nephropathy group and in both groups lower when compared to control groups. Western blot results were consistent with immunohistochemical data. Electron microscopy revealed signs of impaired autophagy in FSGS. Autophagic activity decreased significantly after miR-214, miR-132 and miR-34c mimics and increased after transfection with antagonists. Significance: These results showed that the role of autophagic activity and decreased expression of PRR in FSGS pathogenesis and miR-34c, miR-132 and miR-214 could be a potential treatment strategy by regulating autophagy.