Human umbilical cord stromal mesenchymal stem cells (hUCS-MSCs) have the potential to differentiate into numerous cell types including epithelial cells, neurons and hepatocytes in vitro, in addition to mesenchyme-derived cells such as osteocytes, chondrocytes and adipocytes. One important property of these cells is the lack of type II major histocompatibility complex class molecules, thus allowing them to be considered as an excellent candidate for transplantations. Besides the use of 5-azacytidine as a supraphysiological inducer of myogenic transformation, no study has been published to date addressing the myogenic transformation efficiency of hUCS-MSCs by using a gene transfection strategy and/or co-culture with muscle cell lines. Here, we demonstrate the reprogramming efficiency of these cells, which differentiate into myocytes in vitro by MyoD transcription factor, the master regulator of skeletal muscle differentiation. Once induced via MyoD expression, hUCS-MSCs exhibited many cellular signs of myogenic conversion within 5 days and became capable of forming multinucleated myofibers, which exhibited all functional markers of fusion machinery such as β-catenin, neural cell adhesion molecule and M-cadherin as well as muscle cell-specific structural proteins including desmin, α-actinin, dystrophin, myosin heavy chain, and myoglobin together with muscle-specific enzyme, creatinine phosphokinase. Furthermore, programmed hUCS-MSCs were also capable of fusing with rat primary myoblasts to form heterokaryonic myotubes. Taken together, this study demonstrates the success of a novel cell reprogramming approach to be further evaluated at the in vivo level for use in restoring the defective dystrophin function as intrinsically found in the skeletal muscle fibers of Duchenne muscular dystrophy patients.

Aim To show the importance of prenatal diagnosis of Duchenne Muscular Dystrophy (DMD) and to demonstrate the effect of DMD gene mutations on gestational outcomes. Materials and Methods We retrospectively evaluated 89 pregnancies in 81 individuals who were referred to Hacettepe University for prenatal diagnosis of DMD between January 2000 and December 2015. Prenatal diagnostic methods (chorionic villus sampling (CVS): 66, amniocentesis (AC): 23) were compared for test results, demographic features, and obstetric outcomes of pregnancies. The female fetuses were divided into two groups according to the DMD status (healthy or carrier) to understand the effect of DMD gene mutations on obstetric outcomes. Results Eight prenatally diagnosed disease-positive fetuses were terminated. There was no statistically significant difference between the CVS and AC groups in terms of study variables. There were 46 male fetuses (51.6%) and 43 female fetuses (48.4%). Fifteen of the female fetuses were carriers (34.8%). Median birthweight values were statistically insignificantly lower in the carrier group. Conclusion Pregnancies at risk for DMD should be prenatally tested to prevent the effect of disease on families and DMD carrier fetuses had obstetric outcomes similar to DMD negative female fetuses.

Objective: ST6 beta-galactosamide α-2,6-sialyltranferase 1 (ST6GAL1), the major α2,6-sialyltransferase responsible for the broad synthesis of glycoproteins and glycolipids, is another physiological substrate of Beta site APP-cleaving enzyme 1 (BACE1) other than amyloidbeta precursor protein (AbetaPP). We have previously shown that AbetaPP overexpression in C2C12 mouse myoblast cell line increased the expression and secretion of ST6GAL1 enzyme under in vitro conditions. Since the secretion of ST6GAL1 is known to be enhanced during inflammation, we investigated whether AbetaPP induced ST6GAL1 secretion from C2C12 cells affected proinflammatory cytokine production by J774 mouse macrophage cell line. Methods: J774 macrophage cells were cultured with conditioned medium derived from either AbetaPP or ST6GAL1 overexpressing C2C12 cells and analyzed for proinflammatory cytokine (tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6) expression by quantitative realtime PCR (qRT-PCR). Also, culture supernatants were analyzed for IL-1β release by ELISA. Results:The results of our study demonstrated that secretion of ST6GAL1 enzyme from either AbetaPP or ST6GAL1 overexpressing C2C12 cells induces the expression of TNF-α, IL-1β, IL-6 and the secretion of IL-1β by J774 macrophages. Conclusion: In our study, results were obtained pointing that secreted ST6GAL1 might have a potential role in the inflammation process observed in the muscle tissue. Our results should be confirmed under in vivo system. Key Words: Skeletal muscle, AbetaPP, Abeta, ST6GAL1, inflammation, proinflammatory cytokine Conflict of Interest: Authors have no conflict of interest. ÖZETAmaç: ST6 Beta galaktozamid alfa-2,6-siyaliltransferaz (ST6GAL1), glikolipitlerin ve glikoproteinlerin sentezinde görev alan temel α-2,6 siyaliltransferaz olmasının yanısıra, Beta site APP-cleaving enzyme 1 (BACE1) enziminin amiloid-beta öncül proteini (AbetaPP) dışındaki fizyolojik substratlarından biridir. Daha önce yapmış olduğumuz in vitro çalışmada; AbetaPP'nin yüksek düzeyde ifadesinin sağlandığı C2C12 hücrelerinde, ST6GAL1'in ifade düzeyinin ve salgılanma seviyesinin arttığı saptanmıştır. ST6GAL1 salgılanma seviyesinin inflamasyon sürecine bağlı olarak arttığı bilinmektedir. Bu nedenle, C2C12 hücrelerinde AbetaPP'nin yüksek düzeyde ifadesine bağlı olarak artan ST6GAL1 salgılanmasının, J774 fare makrofaj hücrelerinde proinflamatuar sitokinlerin ifade ve salgılanması üzerindeki etkileri araştırılmıştır. Metod: AbetaPP veya ST6GAL1 enziminin yüksek düzeyde ifadesinin sağlandığı C2C12 hücrelerinin süpernatanı ile kültüre edilen J774 makrofaj hücrelerinde, kantitatif gerçek zamanlı PCR (qRT-PCR) ile proinflamatuar sitokinlerin (tümör nekroz faktör (TNF)-α, interlökin (IL)-1β ve IL-6) ifadesi analiz edilmiştir. Ayrıca, kültür süpernatanlarında ELISA yöntemi ile IL-1β salgılanma analizi gerçekleştirilmiştir. Bulgular: AbetaPP veya ST6GAL1 enziminin yüksek düzeyde ifadesinin sağlandığı C2C12 hücrelerinden salgılanan ST6GAL1'in, J774 hücrelerinde TNF-α, IL-1β, IL-6 if...

Mitokondri, oksidatif fosforilasyon ile ATP üretiminin yanı sıra üstlendiği görevler ile hücre canlılığının sürdürülebilmesinde merkezi öneme sahip çok işlevli bir organeldir. Organelin hücre canlılığına katkıda bulunmasında rol oynayan en temel özelliklerinden biri de kendine özgül genetik sistemidir. Mitokondriyal DNA (mtDNA)'nın normal fizyolojik koşullarda organelin matriks kısmında bulunduğu, fakat gerek organel gerekse hücre hasarı olduğu durumda hücre dışı matrise salınarak serbest dolaşıma katıldığı belirtilmiştir. Özellikle son yıllarda mtDNA'ya ilişkin yapılan çalışmalar, organel genomunun dolaşımda üstlendiği roller ve hastalıklarla ilişkisi üzerine yoğunlaşmıştır. Sistemik dolaşımda serbest halde bulunan mtDNA'lar [circulating cell free mtDNA (ccf-mtDNA)] bağışıklık sisteminde görevli Kalıp Tanıma Reseptörleri [Pattern Recognition Receptors (PRRs)] tarafından Hasarla İlişkili Moleküler Yapılar [Damage Associated Molecular Patterns (DAMPs)] olarak algılanarak pro-inflamatuar yanıt oluşumunda temel bir rol üstlenmektedir. Bu derlemede, ccf-mtDNA'nın sistemik dolaşıma katılma mekanizmaları ve etkileşimde bulunduğu yolakların detayına inilerek, bağışıklık sisteminin bir uyaranı olarak görev almasına ve hastalıklarla ilişkisine dair bilgiler özetlenmiştir.

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