Endoplasmic Reticulum Stress and Homeostasis in Reproductive Physiology and Pathology

The endoplasmic reticulum (ER), comprises 60% of the total cell membrane and interacts directly or indirectly with several cell organelles i.e., Golgi bodies, mitochondria and proteasomes. The ER is usually associated with large numbers of attached ribosomes. During evolution, ER developed as the specific cellular site of synthesis, folding, modification and trafficking of secretory and cell-surface proteins. The ER is also the major intracellular calcium storage compartment that maintains cellular calcium homeostasis. During the production of functionally effective proteins, several ER-specific molecular steps sense quantity and quality of synthesized proteins as well as proper folding into their native structures. During this process, excess accumulation of unfolded/misfolded proteins in the ER lumen results in ER stress, the homeostatic coping mechanism that activates an ER-specific adaptation program, (the unfolded protein response; UPR) to increase ER-associated degradation of structurally and/or functionally defective proteins, thus sustaining ER homeostasis. Impaired ER homeostasis results in aberrant cellular responses, contributing to the pathogenesis of various diseases. Both female and male reproductive tissues undergo highly dynamic cellular, molecular and genetic changes such as oogenesis and spermatogenesis starting in prenatal life, mainly controlled by sex-steroids but also cytokines and growth factors throughout reproductive life. These reproductive changes require ER to provide extensive protein synthesis, folding, maturation and then their trafficking to appropriate cellular location as well as destroying unfolded/misfolded proteins via activating ER-associated degradation mediated proteasomes. Many studies have now shown roles for ER stress/UPR signaling cascades in the endometrial menstrual cycle, ovarian folliculogenesis and oocyte maturation, spermatogenesis, fertilization, pre-implantation embryo development and pregnancy and parturition. Conversely, the contribution of impaired ER homeostasis by severe/prolong ER stress-mediated UPR signaling pathways to several reproductive tissue pathologies including endometriosis, cancers, recurrent pregnancy loss and pregnancy complications associated with pre-term birth have been reported. This review focuses on ER stress and UPR signaling mechanisms, and their potential roles in female and male reproductive physiopathology involving in menstrual cycle changes, gametogenesis, preimplantation embryo development, implantation and placentation, labor, endometriosis, pregnancy complications and preterm birth as well as reproductive system tumorigenesis

Okullarda Düzenli Aralıklarla Gerçekleştirilen Kontroller Saç Biti (Pediculus capitis) İnsidansını Düşürmekte Yeterli Olabilir mi?

In the present study, school children of similar age-groups from two villages of Manisa province, namely Osmancalı and Maldan, were examined in regular time periods to monitorize the changes in the incidence of head lice (Pediculus capitis). A total of 2091 children (1565 in Osmancalı and 526 in Maldan) were combed with a newly-designed lice comb (PDC;reg;, KSL Consulting, Helsinge, Denmark) four times in May and November in 2008 and 2009. The assessment of the results was conducted with SPSS;reg; v.15 program using CHAID and logistic regression analysis. The results of the periodic examinations of the children showed that the infestation rate of girls were found to be higher significantly compared to boys (P;lt;0.001), and the incidence of head lice infestation in boys from Osmancalı was found three times higher than the incidence in boys in Maldan (P=0.002). In addition, regular dry combing and treatment lowered the infestation rates among girls significantly (P=0.001). According to the results of the study, regular dry combing of school children with specially-designed lice combs may be essential for the control of this common infestation, especially in rural areasÇalışmamızda Manisa'nın Osmancalı ve Maldan köylerindeki ilköğretim okullarında aynı yaş grubundaki çocuklarda belirli aralıklarla saç biti (Pediculus capitis) taramaları yapılmış ve çocuklardaki bit varlığındaki değişimler izlenerek kaydedilmiştir. Bu bağlamda, 2008 ve 2009 yıllarının Mayıs ve Kasım aylarında o zaman için yeni geliştirilmiş bir bit tarağı (PDC®, KSL Consulting, Helsinge, Danimarka) kullanılarak yapılan düzenli taramalarda, (1565'i Osmancalı, 526'sı Maldan'dan) toplam 2091 çocuk çalışmaya dâhil edilmiştir. Sonuçların değerlendirilmesi SPSS® v.15 programının CHAID ve lojistik regresyon analizi kullanılarak yapılmıştır. Düzenli aralıklarla toplam 4 kez gerçekleştirilen taramalar sonucunda, kızlarda saç biti infestasyonunun erkeklerden çok daha yüksek düzeylerde olduğu (P0.001), Osmancalı'daki erkek öğrencilerdeki insidansın Maldan'daki erkeklerin yaklaşık 3 katı olduğu (P=0.002) gözlenmiştir. Ayrıca, düzenli tarama ve tedaviler sonucunda kızlardaki saç biti infestasyonunun anlamlı düzeyde azaldığı belirlenmiştir (P=0.001). Bu çalışmanın sonuçları, saç biti infestasyonunun kontrol altına alınmasında düzenli aralıklarla yapılan muayene ve tedavilerin özellikle kırsal kesimde başarılı olabileceğini göstermişti