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Book Part Citation - WoS: 15Citation - Scopus: 15Comparison of Hematopoietic and Spermatogonial Stem Cell Niches From the Regenerative Medicine Aspect(Springer international Publishing Ag, 2018) Kose, Sevil; Yersal, Nilgun; Onen, Selin; Korkusuz, PetekRecent advances require a dual evaluation of germ and somatic stem cell niches with a regenerative medicine perspective. For a better point of view of the niche concept, it is needed to compare the microenvironments of those niches in respect to several components. The cellular environment of spermatogonial stem cells' niche consists of Sertoli cells, Leydig cells, vascular endothelial cells, epididymal fat cells, peritubular myoid cells while hematopoietic stem cells have mesenchymal stem cells, osteoblasts, osteoclasts, megacaryocytes, macrophages, vascular endothelial cells, pericytes and adipocytes in their microenvironment. Not only those cells', but also the effect of the other factors such as hormones, growth factors, chemokines, cytokines, extracellular matrix components, biomechanical forces (like shear stress, tension or compression) and physical environmental elements such as temperature, oxygen level and pH will be clarified during the chapter. Because it is known that the microenvironment has an important role in the stem cell homeostasis and disease conditions, it is crucial to understand the details of the microenvironment and to be able to compare the niche concepts of the different types of stem cells from each other, for the regenerative interventions. Indeed, the purpose of this chapter is to point out the usage of niche engineering within the further studies in the regenerative medicine field. Decellularized, synthetic or non-synthetic scaffolds may help to mimic the stem cell niche. However, the shared or different characteristics of germ and somatic stem cell microenvironments are necessary to constitute a proper niche model. When considered from this aspect, it is possible to produce some strategies on the personalized medicine by using those artificial models of stem cell microenvironment.Article Citation - WoS: 3Citation - Scopus: 3Detection of spermatogonial stem/progenitor cells in prepubertal mouse testis with deep learning(Springer/plenum Publishers, 2023) Kahveci, Burak; Onen, Selin; Akal, Fuat; Korkusuz, PetekPurposeRapid and easy detection of spermatogonial stem/progenitor cells (SSPCs) is crucial for clinicians dealing with male infertility caused by prepubertal testicular damage. Deep learning (DL) methods may offer visual tools for tracking SSPCs on testicular strips of prepubertal animal models. The purpose of this study is to detect and count the seminiferous tubules and SSPCs in newborn mouse testis sections using a DL method.MethodsTesticular sections of the C57BL/6-type newborn mice were obtained and enumerated. Odd-numbered sections were stained with hematoxylin and eosin (H&E), and even-numbered sections were immune labeled (IL) with SSPC specific marker, SALL4. Seminiferous tubule and SSPC datasets were created using odd-numbered sections. SALL4-labeled sections were used as positive control. The YOLO object detection model based on DL was used to detect seminiferous tubules and stem cells.ResultsTest scores of the DL model in seminiferous tubules were obtained as 0.98 mAP, 0.93 precision, 0.96 recall, and 0.94 f1-score. The SSPC test scores were obtained as 0.88 mAP, 0.80 precision, 0.93 recall, and 0.82 f1-score.ConclusionSeminiferous tubules and SSPCs on prepubertal testicles were detected with a high sensitivity by preventing human-induced errors. Thus, the first step was taken for a system that automates the detection and counting process of these cells in the infertility clinic.Article Citation - WoS: 3Citation - Scopus: 3Development and Validation of a Sensitive Assay for the Quantification of Arachidonoylcyclopropylamide (acpa) in Cell Culture by Lc-ms/Ms(Springer int Publ Ag, 2023) Boyacioglu, Ozge; Recber, Tuba; Kir, Sedef; Korkusuz, Petek; Nemutlu, EmirhanSynthetic and natural cannabinoid derivatives are highly investigated as drug candidates due to their antinociceptive, antiepileptic and anticancer potential. Arachidonoylcyclopropylamide (ACPA) is a synthetic cannabinoid with antiproliferative and apoptotic effects on non-small cell lung cancer and pancreatic and endometrial carcinoma. Thus, ACPA has a great potential for being used as an anticancer drug for epithelial cancers. Therefore, determining the levels of ACPA in biological fluids, cells, tissues and pharmaceutical dosage forms is crucial in monitoring the effects of various pharmacological, physiological and pathological stimuli on biological systems. However, the challenge in the quantification of ACPA is its short half-life and lack of UV signal. Therefore, we developed a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for sensitive and selective quantification of ACPA in cell culture medium and intracellular matrix. Multiple reaction monitoring in the positive ionization mode was used for detection with 344 -> 203 m/z transitions. The separation of ACPA was performed on C18 column (50 x 3.0 mm, 2.1 mu m) with the mobile phase run in the gradient mode with 0.1% formic acid (FA) in water and 0.1% FA in acetonitrile at a flow rate of 0.3 ml/min. The assay was linear in the concentration range of 1.8-1000 ng/mL (r = 0.999). The validation studies revealed that the method was linear, sensitive, accurate, precise, selective, repeatable, robust and rugged. Finally, the developed method was applied to quantify ACPA in cell culture medium and intracellular matrix.Article Citation - WoS: 1Citation - Scopus: 1Topical Intranasal Insulin Enhances Healing of Nasal Mucosa: an Experimental Animal Study(Sage Publications inc, 2023) Kulekci, Cagri; Ozer, Serdar; Onen, Selin; Korkusuz, Petek; Yilmaz, TanerObjective Aim of this study was to evaluate the effect of topical intranasal insulin on healing of nasal mucosa in a rat model. Methods Forty-eight Wistar rats, weighing between 250 and 300 g and aged 10-12 weeks were used and randomized into two equal groups. 1.9 mm curette was introduced through the left nostril and 1.9 mm mucosa from the left nasal septum was curetted. Postoperatively, animals in the control group received 1 mL of physiologic saline, 3 times a day in a nasal irrigation fashion. Animals in the experimental group received 1 mL of 5 IU/mL regular insulin in saline solution. Subjects were sacrificed after 5, 10, and 15 days and macroscopic and histomorphometric evaluations were performed. Results There were no mucosal synechiae and septal perforation macroscopically. Histological examination revealed that the defect size reduction was 21% in the saline group versus 56% in the insulin group on the fifth day (p = 0.006). There was 62% defect reduction in the saline group versus 79% in the insulin group on the 10th day (p = 0.034). On the 15th day, only 67% of saline group animals had complete defect closure, whereas 100% of animals treated with insulin had complete closure (92% vs 100% mucosal defect reduction, p = 0.036). Both edema and inflammation were less in the insulin group on 15th day (p = 0.006; p = 0.023, respectively). Conclusion The results from this study support the safety and efficacy of topical insulin on wound healing in the literature. This study could guide further experimental studies that examine human sinonasal wound healing.Book Part Citation - WoS: 13Citation - Scopus: 14Neurological Regulation of the Bone Marrow Niche(Springer international Publishing Ag, 2020) Aerts-Kaya, Fatima; Ulum, Baris; Mammadova, Aynura; Kose, Sevil; Aydin, Gozde; Korkusuz, Petek; Uckan-Cetinkaya, DuyguThe bone marrow (BM) hematopoietic niche is the microenvironment where in the adult hematopoietic stem and progenitor cells (HSPCs) are maintained and regulated. This regulation is tightly controlled through direct cell-cell interactions with mesenchymal stromal stem (MSCs) and reticular cells, adipocytes, osteoblasts and endothelial cells, through binding to extracellular matrix molecules and through signaling by cytokines and hematopoietic growth factors. These interactions provide a healthy environment and secure the maintenance of the HSPC pool, their proliferation, differentiation and migration. Recent studies have shown that innervation of the BM and interactions with the peripheral sympathetic neural system are important for maintenance of the hematopoietic niche, through direct interactions with HSCPs or via interactions with other cells of the HSPC microenvironment. Signaling through adrenergic receptors (ARs), opioid receptors (ORs), endocannabinoid receptors (CRs) on HSPCs and MSCs has been shown to play an important role in HSPC homeostasis and mobilization. In addition, a wide range of neuropeptides and neurotransmitters, such as Neuropeptide Y (NPY), Substance P (SP) and Tachykinins, as well as neurotrophins and neuropoietic growth factors have been shown to be involved in regulation of the hematopoietic niche. Here, a comprehensive overview is given of their role and interactions with important cells in the hematopoietic niche, including HSPCs and MSCs, and their effect on HSPC maintenance, regulation and mobilization.Article Citation - WoS: 14Citation - Scopus: 15Leptin Promotes Proliferation of Neonatal Mouse Stem/Progenitor Spermatogonia(Springer/plenum Publishers, 2020) Yersal, Nilgun; Kose, Sevil; Horzum, Utku; Ozkavukcu, Sinan; Orwig, Kyle E.; Korkusuz, PetekPurpose To keep and increase spermatogonial stem cell number (SSC) is the only available option for pediatric cancer survivors to maintain fertility. Leptin is secreted by the epididymal white adipose tissue and has receptors on stem/progenitor spermatogonia. The purpose of this study is to demonstrate dose- and time-dependent proliferative effect of leptin on stem/progenitor spermatogonia cultures from prepubertal mice testes. Methods CD90.2 (+) stem/progenitor spermatogonia were isolated from the C57BL/6 mouse testis on postnatal day 6 and placed in culture. The proliferative effect of leptin supplementation was assessed by colony formation (diameter and number), WST proliferation assays, and xCELLigence real-time cell analysis (RTCA) on days 3, 5, and 7 of culture. Expressions of p-ERK1/2, p-STAT3, total STAT3, and p-SHP2 levels were determined by western blot analysis. Results Leptin supplementation of 100 ng/ml increased the diameter (p= 0.001) and number (p= 0.01) of colonies in stem/progenitor spermatogonial cultures and caused higher proliferation by WST-1 (p= 0.009) compared with the control on day 7. The EC50 was calculated as 114 ng/ml for leptin by RTCA. Proliferative dose of leptin induced increased expression of p-ERK1/2 (p= 0.009) and p-STAT3 (p= 0.023) on stem/progenitor spermatogonia when compared with the untreated group. Conclusion The results indicated that leptin supplementation exhibited a dose- and time-dependent proliferative effect on stem/progenitor spermatogonia that was associated with increased expression of ERK1/2 and STAT3 pathways while maintaining their undifferentiated state. This output presents a new agent that may help to expand the stem/progenitor spermatogonia pool from the neonatal testis in order to autotransplant after cancer treatment.Book Part Citation - WoS: 18Citation - Scopus: 23Stem Cell and Advanced Nano Bioceramic Interactions(Springer-verlag Singapore Pte Ltd, 2018) Kose, Sevil; Kankilic, Berna; Gizer, Merve; Dede, Eda Ciftci; Bayramli, Erdal; Korkusuz, Petek; Korkusuz, FezaBioceramics are type of biomaterials generally used for orthopaedic applications due to their similar structure with bone. Especially regarding to their osteoinductivity and osteoconductivity, they are used as biodegradable scaffolds for bone regeneration along with mesenchymal stem cells. Since chemical properties of bioceramics are important for regeneration of tissue, physical properties are also important for cell proliferation. In this respect, several different manufacturing methods are used for manufacturing nano scale bioceramics. These nano scale bioceramics are used for regeneration of bone and cartilage both alone or with other types of biomaterials. They can also act as carrier for the delivery of drugs in musculoskeletal infections without causing any systemic toxicity.
