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• We aimed to demonstrate its functionality by inserting it into pTRE-Luc vector.
• We expect that HRE, as an enhancer, would activate the promoter existing on the downstream region of it, depending on the level of HIF1alfa in the media which is increased in hypoxic conditions.

Expected To understand which colony our gene is inserted among the colonies that we transformated pHRE-luciferase vector, we expected the picture above when we perform PCR when we use pTRE-Luc forward and MCS reverse primers.

Experimented From the samples we perform colony PCR by using pTRE-Luc forward and MCS reverse primers, we obtained a band in 428 bp line. This image proves that our HRE sequnce is inserted into the vector, successfully.

Luciferase Assay

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NF-kappaB (NF-kB) proteins comprise a family of structurally-related eukaryotic transcription factors that are involved in the control of a large number of normal cellular and organismal processes, such as immune and inflammatory responses, developmental processes, cellular growth, and apoptosis. In some circumstances, NF-kB/IkB complex can be separated by external effects such as radiation, cellular stress, pathogens, inflammation etc. In this case, NF-kB can enter into nucleus and integrate with compatible kB-RE sites in order to initiate transcription.

We cloned kB-RE and inserted it into the upstream region of CMV mini promoter as it’s shown above.

NF-kappaB (NF-kB) was synthesized to GenScript™ company and it came in pUC57 plasmid. We digested it with BamHI & PstI and exposed it to Antarctic phosphatase.

Afterwards, we purified our part via phenol chloroform method. We performed the same procedures onto the pTRE-luciferase vector. Eventually, we ligated them.

We inserted our plasmid (pTRE-luciferase kB-RE) into DH5α strain and performed colony PCR by using CMV forward and kB reverse primers. At the end of this experiment, we expected a band seen in the 20-30 bp line.

And we observed correct bands in the expected region.

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As the amount of IAA needed for enhancing plant growth depends on whether our bacteria are producing the compound outside or inside the plants, we attempted to replicate these findings.

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Tissue plasminogen activator (abbreviated tPA or PLAT) is a protein involved in the breakdown of blood clots. It is a serine protease (EC 3.4.21.68) found on endothelial cells and (hücreden plazmaya salgılanır), the cells that line the blood vessels. As an enzyme, it catalyzes the conversion of plasminogen to plasmin, the major enzyme responsible for clot breakdown. Because it works on the clotting system, tPA is used in clinical medicine to treat embolic or thrombotic stroke. Use is contraindicated in hemorrhagic stroke and head trauma.

The question is, how can tPA enzyme activity be measure? We sought the answer to the question in the examination of the yield of a tPA catalyzed reaction. We searched the sector, in which we found the the Human tPA Activity Kit of the company ASSAYPRO that we then ordered and used. In the reaction which tPA catalyzed, we aimed to show that tPA was active through the transformation of plasminogen to plasmine.

To acquire the tPA gene, the tPA forward and tPA revers primers were synthesized from the cDNA’s we were in possession of. Then, by also using these primers, we acquired the tPA genes through the PCR of the cDNA. The head and neck cancer cell line was used as the source for cDNA.

GENE SYNTHESIS FROM cDNA OF 64A CELL LINE

Expected The base length of tPA is 1762 bp’dir. The electrophoresis of the PCR was expected to show a base length of around 1700 bp. The image below shows the expected result of the electrophoresis.

Experimented Through the primers that we ordered and the cDNA, we acquired tPA inserts. The insert was, as expected, portraying that the base length was around 1700 bp.

Elde ettiğimiz insertleri ve pTRE vektörünü EcoRI ve BamHI enzimleri ile kestik. Ardından sahip olduğumuz ligation Protocolüne göre insert ve vektörü birleştirmeye çalıştık. Ligation neticesinde elde ettiğimiz plasmitleri E. coli’nin DH5-α suşuna transforme ettik. Transformasyon sonrasında ligationın doğruluğunu kontrol etmek amacıyla colony PCR yaptık.

CLONING CONTROL-1

Expected The acquired inserts were ligated to the pTRE vector and the ligate was transformated to the E.coli strands DH5-α. To confirm the results of the transformation, colony PCR was conducted using CMV forward and tPA revers primers. The picture above shows the expected base length of the insert, which was 1894 bp.

Experimented The specified primers were put into colony PCR. As it can be seen in the results above, a right insert was not achieved. This process was repeated several times but no result was achieved. Seeing that ligation did not provide a solution to the problem, synthetically produced inserts were ordered.

Expected The base length of tPA is 1762 bp’dir. The electrophoresis of the PCR was expected to show a base length of around 1700 bp. The image below shows the expected result of the electrophoresis.

Experimented Through the primers that we ordered and the cDNA, we acquired tPA inserts. The insert was, as expected, portraying that the base length was around 1700 bp.

Sentetik olarak sentezlenen ve pUC57 vektörü içerisinde gönderilen tPA genini EcorI ve BamHI enzimleri ile kesip pTRE vektörüne ligation yaptık ve tekrar DH5-α suşuna transforme ettik. Ligation doğruluğunu kontrol etmek amacıyla colony PCR yaptık.

CLONING CONTROL-2

Expected The received genes were ligated with the pTRE vector, and then transformated to E.coli strands DH5-α. To test the validity of the transformation, we again applied colony PCR through CMV forward and SV40 reverse primers. The expected base length was 1984 bp.

Experimented Colony PCR was applied to the inserts acquired from transformation and ligation. As it can be seen in the figure above, the second colony contains the appropriate base length in respect to the ladder.

WESTERN BLOTTİNG

Expected The confirmed genes were transfected into HEK293 cells. The lysates acquired from the cells were run through Western Blot. tPA, that is known to have 63 kD, was expected to have the image on the left. http://www.emdmillipore.com/TR/en/product/Anti-tPA-%28Tissue-Plasminogen-Activator%29-Antibody%2C-clone-GMA-043,MM_NF-05-883

Experimented The bands in the Western Blot were accurate. The transfection of the inserts were verified and assays of tPA were prepared from the lysates.

After having proven the presence of tPA expression in the cells transfected with Western Blotting, the concentration of the amount of tPA in the cell and the amount of secreted tPA were measured using the ‘Human tPA Activity Kit’ to show that the expressed proteins are functionally active.

The real parameter of the measurement in the Assay was the product of the reaction of the plasmin enzyme. Since tPA shifts the inactive plasminogen to active plasmine, the measured value also presents tPA activity. The yield gives absorbance at 405 nm.

tPA ASSAY

Experimented

tPA assay sonucuna göre tPA enziminin hücremizde üretildiğini ve hücre dışına salgılandığını kanıtlayarak tPA’nın fonksiyonel olarak aktif olduğunu ve hücre içinde üretilerek hücre dışına salgılandığını kanıtladık.

Through the result of the tPA Assay, we proved that the tPA is functionally active through showing that tPA was produced in the cell and was secreted out of the membrane.

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GENE SYNTHESIS FROM HEPG2 CELL LINE cDNA

SOD is a powerful and essential antioxidant enzyme which converts and scavenges free radicals and reactive oxygen species (ROS) into hydrogen peroxide (H2O2), a compound slightly less harmful,in order to convey it to the second step reaction which detoxifies H2O2 into water. Once cloning our SOD gene and placing into the pTRE luciferase vector, we expect to see the expression of this clone in the eukaryotic HEK(Human Embryonic Kidney) 293 T cell line using the western blotting technique. SOD assay procedure will be used to measure the expression of our SOD gene hence proving that our SOD enzyme is functioning as expected. Below are the results of each strep taken until the functional assay:

Expected The gel electrophoresis above shows the expected result of the amplified SOD1 gene using the CMW forward and SV40 reverse primers we obtained from the HEP2G cell line. According to the results , we aim to see a band at 526bp.

Experimented We amplified the SOD1 genes using CMV forward and SV40 reverse primers and achieved results by viewing band at 526bp.

cDNA obtained from HEP 2G cells have been used to perform PCR to synthesize our desired inserts. EcoRI and BamHI were the choice of enzymes to digest our inserts once their purification was accomplished using phenol chloroform method. Transformation using the DH5α strain was the next step after ligating our inserts with the pTRE vectors. Colony PCR procedure was conducted using the CMV forward and SV40 reverse primers to ensure that our inserts were cloned correctly. Below are the results of our Colony pcr procedure:

COLONY PCR

Expected Upon transforming, in order to ensure that our insert is placed correctly ,we expect to see the above results using the colony pcr technique. We decided to use CMV forward and SV40 reverse primers for pcr.

Experimented According to the forth colony, our results show that sod1-ptre vector has been inserted correctly.

In order to prove that our cloning has been carried out correctly we used the restriction-digest process and achieved the expected results. We cotransfected our vector with HEK 293 T cell line. After incubating our cells we performed western blotting and controlled the cell expression of our SOD1 genes. Below is our western blotting results:

WESTERN BLOTTING

Expected (Link for picture)

Experimented Our western Blotting results show a band at 18kDa meaning that our HEK 293 T cell line has been successful.

Functional assay of SOD was performed to test whether our enzyme was functioning as expected.

Characterisation

Dosage levels were adjusted whilst SOD- Ptre vector was transfected to HEK293 cell. 1. 125ng/24-well gene transfected to 105 cells present in well. 2. 250ng/24-well gene transfected to 105 cells present in well. 3. 500ng/24-well gene transfected to 105 cells present in well. The results show that the SOD1 gene is effected by the adjustement of dosage levels which in return proves that as the amount of transfected genes increase the gene expression also increases

SOD ASSAY

Superoxide Dismutase 1 changes the oxygen radicals into 02 and H2O2. Using this feature of SOD we placed the oxygen radicals into the same solution as tetrazolium dye which uses the radicals as substrates and enabled them to compete. Hence this allowed us to measure the functional activity of SOD produced by our transfected cells using the spectrophotometer at 560 nm.

Transfected Tet off - pTRE and Tet off - pTRE-SOD1 vectors were subjected to SOD assay and measured using the spectrophotometer at 560 nm. Cells which have the Tet off – pTRE SOD1 gene present can degrade the oxygen radicals 21 times faster. SOD assay was performed for the proteins obtained from the transfected SOD1 visible colour change could be seen.

His tagged Aprotinin (BPTI), SOD1, GPX1 and PLAT (tPA) was overexpressed in HEK 293T cells. 36 hours post transfection cells were collected and subjected to western blotting. Aprotinin, SOD1 and tPA were expressed. However, expression of GPX1 could not be observed. Previously, we realized that GPx-1 is a member of seleno-cystein proteins. To code seleno-cystein GPx has a internal stop codon. Expression in the absense of seleno-cystein GPX-1 expression stops at the internal stop codon thus, the his-tag at the and of GPx-1 can not be expressed. Therefore,we couldn’t see any band in westernblotting. Next , we planned to add sodiumselenite to induce production of seleno-cystein.

This is comassive blue flourorange view of blotted membrane.

The expression level of beta actin is the same among samples.

This is comassive blue flourorange view of blotted membrane.

We over expressed SOD-1 and tPA with different doses of SOD-1 and tPA expression vector. SOD-1 well responded to the increasing doses. tPA gave the same response to all different doses. To induce expression of GPx-1 the cells treated with different doses of sodiumselenite and GPx-1 proportionally response to the increasing doses of sodiumselenite with single dose of expression vector.

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Geri İleri

Retrieved from "http://2014.igem.org/Team:ATOMS-Turkiye/Results"

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