Browsing by Subject "Cloning"

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Open Access
Cloning and expression profile of FLT3 gene during progenitor cell-dependent liver regeneration
(Blackwell Publishing, 2007) Aydin, I. T.; Tokcaer, Z.; Dalgic, A.; Konu, O.; Akcali, K. C.
Background and Aim: The liver has a unique capacity to regenerate upon exposure to viral infections, toxic reactions and cancer formation. Liver regeneration is a complex phenomenon in which several factors participate during its onset. Cellular proliferation is an important component of this process and the factors that regulate this proliferation have a vital role. FLT3, a well-known hematopoietic stem cell and hepatic lineage surface marker, is involved in proliferative events of hematopoietic stem cells. However, its contribution to liver regeneration is not known. Therefore, the aim of this study was to clone and examine the role of FLT3 during liver regeneration in rats. Methods: Partial cDNA of rat homolog of FLT3 gene was cloned from thymus and the tissue specific expression of this gene at mRNA and protein levels was examined by RT-PCR and Western blot. After treating with 2-AAF and performing hepatectomy in rats to induce progenitor-dependent liver regeneration, the mRNA and protein expression profile of FLT3 was investigated by real-time PCR and Western blot during liver regeneration. In addition, cellular localization of FLT3 protein was determined by immunohistochemistry. Results: The results indicated that rat FLT3 cDNA has high homology with mouse and human FLT3 cDNA. It was also found that FLT3 is expressed in most of the rat tissues and during liver regeneration. In addition, its intracellular localization is altered during the late stages of liver regeneration. Conclusion: The FLT3 receptor is activated at the late stages of liver regeneration and participates in the proliferation response that is observed during progenitor-dependent liver regeneration. © 2006 The Authors.
Open Access
Expression and purification of the hepatitis C virus core protein in Ecoli and testing of human sera with this core antigen
(1998) Eroğlu, Çağla
The hepatitis C virus (HCV) infection is an important cause of morbidity and mortality world wide. Infection with HCV becomes chronic in more than 80% of the cases and it accounts for 20%of all cases of acute hepatitis. Hepatitis C virus was first identified by the molecular cloning of the virus genome in 1989. It is an enveloped, positive strand RNA virus with a genome size of around 9.5 Idlobases. The single stranded RNA genome of the virus contains a large open reading frame codes for a large poly-protein of 3,010 to 3,033 amino acids which is shown to be processed by a combination of host and viral proteinases to produce at least ten proteins post-translationally. The proteins that are closer to the amino terminal of the poly-protein are termed as structural and the rest closer to the carboxy terminal are called non-structural (NS) proteins. The core protein is the putative nucleocapsid component of the virion, and it is highly basic in nature. Core protein is the most highly conserved region of the hepatitis C virus open reading frame and it is shown to be highly immunogenic. Also, as the core protein is the putative capsid protein of the hepatitis C virus, antibodies against core antigen most probably arise much earlier than the antibodies against nonstructural proteins. In this study, the core protein of the hepatitis C virus was cloned, expressed and purified in order to establish an ELISA system to test the human sera with this viral antigen. It was shown that in 86% of the patients, diagnosed previously with the third generation enzyme immunoassays to be infected with hepatitis C, have antibodies against this core antigen. The core antigen gave no false positive results when tested with the negative control samples which were found to be Anti-HCV negative previously.
Open Access
A highly sensitive and specific enzyme-linked immunosorbent assay of antibodies to hepatitis C virus
(2000) Eroğlu, C.; Yıldız, E.; Öztürk, M.; Pınarbaşı, E.
In this study, a 178 amino acids long portion of the hepatitis C virus (HCV) core gene was cloned, sequenced, expressed in Escherichia coli, and purified. The resulting antigen (C178) was tested with human sera enzyme-linked immunosorbent assay (ELISA) in order to assess its ability to diagnose HCV. It was shown by ELISA that 92% of the patients sera, diagnosed previously by a 3(rd) generation enzyme immunoassay (EIA) as HCV-positive, had antibodies against the C178 antigen. This antigen gave no false positive results when tested with anti-HCV-negative sera.