Journal of Literature Pharmacy Sciences

Oksisteroller: Hücresel Etkileri ve Kronik Hastalıklarla İlişkileri
Oxysterols: Cellular Effects and Relations with Chronical Diseases
Neslihan AKSUa, Suna SABUNCUOĞLUa
aFarmakoloji Toksikoloji ABD, Hacettepe Üniversitesi Eczacılık Fakültesi, Ankara, TÜRKİYE
J Lit Pharm Sci. 2019;8(3):225-34
doi: 10.5336/pharmsci.2019-65607
Article Language: TR
Full Text
ÖZET
 Oksisteroller, kolesterolün oksidasyonu sonucu oluşan 27-C'li yan ürünleridir. Farklı kimyasal yapılara sahip çok sayıda oksisterol türevi bulunmaktadır. Kolesterol molekülüne bir oksijenli fonksiyonel grubun çeşitli pozisyonlarda eklenmesi ile oluşan oksisteroller, kolesterol molekülünün yarı ömrünü büyük ölçüde azaltmaktadır. Bu moleküller, kolesterolün vücuttan atılımını artırır ya da suda çözünen safra asitlerinin oksidasyon reaksiyonlarına aracılık eder. Ayrıca, molekülün, lipofilik membranları geçmesine olanak sağlar. Oksisteroller, özellikle steroid yan zincirine oksijen eklenmesiyle kolaylıkla hücrelerden dışarı taşınabilir ve böylece ekstrahepatik kaynaklardan kolesterolün uzaklaştırılmasını kolaylaştırır. Oksisteroller, enzimatik ve enzimatik olmayan yollarla olmak üzere iki farklı yolaktan oluşabilir veya üretilir. Dolaşımda ve dokularda enzimatik yolla oluşan oksisteroller daha fazla bulunmaktadır ve bu türevler vücutta önemli biyolojik faaliyetlerin regülasyonunda görevler almaktadır. Enzimatik olmayan (oto-oksidasyon) yolla oluşan oksisterol türevleri ise patolojik olayların oluşumuna katkıda bulunurlar. Sitotoksik ve pro-apoptotik özellikleri yanı sıra inflamatuar yanıtları indükledikleri ve hücre farklılaşma sürecinde yer almaları nedeniyle ateroskleroz, yaşlanma, Alzheimer ve kanser gibi pek çok hastalığın oluşum mekanizmasında rol oynadıkları belirtilmektedir. Memeli dokularında çok düşük konsantrasyonlarda olduğu belirlenen oksisteroller, pek çok patolojik durumda dokularda yüksek düzeylere ulaşabilmektedir. Bu nedenle, kolesterolün atılım yolaklarında oluşan bu moleküllerin hastalıkların teşhisi ve izlenmesinde biyobelirteç olarak kullanılabileceği düşünülmektedir. Bu çalışmada, pek çok hastalığın patogenezi ile de ilişkilendirilen oksisterollerin biyolojik etkileri ve kronik hastalıklarla ilişkileri ortaya konulmuştur.

Anahtar Kelimeler: Oksisteroller; kolesterol; oto-oksidasyon; kronik hastalık
ABSTRACT
 Oxysterols are with 27-C by-side products formed by oxidation of cholesterol. There are numerous oxysterol derivatives with different chemical structures. Oxysterols formed by the addition of an oxygenated functional group to the cholesterol molecule greatly reduce the half-life of the cholesterol molecule. These molecules increase the excretion of cholesterol or mediate the oxidation reactions of water-soluble bile acids. It allows the molecule to pass through the lipophilic membranes. Oxysterols can be easily transported out of the cells with addition of oxygen to the steroid side chain, thus facilitating the removal of cholesterol from extrahepatic sources. Oxysterols can be formed by two different pathways, enzymatic and non-enzymatic pathways. There are more enzymatic occurring oxysterols in circulation and tissues. Enzymatic occurring oxysterols are involved in the regulation of important biological activity in the body. Oxysterol derivatives which are formed by non-enzymatic (auto-oxidation) pathways contribute to the formation of pathological events. In addition to their cytotoxic and pro-apoptotic properties, they induce inflammatory responses and are involved in the process of cell differentiation and they play a role in the formation of many diseases such as atherosclerosis, aging, Alzheimer and cancer. Oxysterols in very low concentrations in mammalian tissues can reach high levels in tissues in pathological conditions. Therefore, it is thought that these molecules formed in cholesterol's excretion pathways can be used as biomarkers in diagnosing and monitoring diseases. In this review, the biological effects of oxysterols associated with the pathogenesis of many diseases and their relationship with chronic diseases have been demonstrated.

Keywords: Oxysterols; cholesterol; auto-oxidation; chronic disease
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5.2. Within hereby "Terms of Use", "Turkiye Klinikleri" reserves the rights for "Turkiye Klinikleri" services, "Turkiye Klinikleri" information, the products associated with "Turkiye Klinikleri" copyrights, "Turkiye Klinikleri" trademarks, "Turkiye Klinikleri" trade looks or its all rights for other entity and information it has through this website unless it is explicitly authorized by "Turkiye Klinikleri".

6. CHANGES IN THE TERMS OF USE

"Turkiye Klinikleri" in its sole discretion may change the hereby "Terms of Use" anytime announcing within the "SITE". The changed terms of the hereby "Terms of Use" will become valid when they are announced. Hereby "Terms of Use" cannot be changed by unilateral declarations of users.

7. FORCE MAJEURE

"Turkiye Klinikleri" is not responsible for executing late or never of this hereby "Terms of Use", privacy policy and "USER Contract" in any situation legally taken into account as force majeure. Being late or failure of performance or non-defaulting of this and similar cases like this will not be the case from the viewpoint of "Turkiye Klinikleri", and "Turkiye Klinikleri" will not have any damage liability for these situations. "Force majeure" term will be regarded as outside of the concerned party's reasonable control and any situation that "Turkiye Klinikleri" cannot prevent even though it shows due diligence. Also, force majeure situations include but not limited to natural disasters, rebellion, war, strike, communication problems, infrastructure and internet failure, power cut and bad weather conditions.

8. LAW AND AUTHORISATION TO FOLLOW

Turkish Law will be applied in practicing, interpreting the hereby "Terms of Use" and managing the emerging legal relationships within this "Terms of Use" in case of finding element of foreignness, except for the rules of Turkish conflict of laws. Ankara Courts and Enforcement Offices are entitled in any controversy happened or may happen due to hereby contract.

9. CLOSING AND AGREEMENT

Hereby "Terms of Use" come into force when announced in the "SITE" by "Turkiye Klinikleri". The users are regarded to agree to hereby contract terms by using the "SITE". "Turkiye Klinikleri" may change the contract terms and the changes will be come into force by specifying the version number and the date of change on time it is published in the "SITE".

 

30.03.2014

Privacy Policy

We recommend you to read the terms of use below before you visit our website. In case you agree these terms, following our rules will be to your favor. Please read our Terms of Use thoroughly.

www.turkiyeklinikleri.com website belongs to Ortadoğu Advertisement Presentation Publishing Tourism Education Architecture Industry and Trade Inc. and is designed in order to inform physicians in the field of health

www.turkiyeklinikleri.com cannot reach to user’s identity, address, service providers or other information. The users may send this information to the website through forms if they would like to. However, www.turkiyeklinikleri.com may collect your hardware and software information. The information consists of your IP address, browser type, operating system, domain name, access time, and related websites. www.turkiyeklinikleri.com cannot sell the provided user information (your name, e-mail address, home and work address, phone number) to the third parties, publish it publicly, or keep it in the website. Gathered information has a directing feature to be a source for the website’s visitor profile, reporting and promotion of the services.

www.turkiyeklinikleri.com uses the taken information:

-To enhance, improve and maintain the quality of the website

-To generate visitor’s profile and statistical data

-To determine the tendency of the visitors on using our website

-To send print publications/correspondences

-To send press releases or notifications through e-mail

-To generate a list for an event or competition

By using www.turkiyeklinikleri.com you are considered to agree that;

-Ortadoğu Advertisement Presentation Publishing Tourism Education Architecture Industry and Trade Inc. cannot be hold responsible for any user’s illegal and immoral behavior,

-Terms of use may change from time to time,

-It is not responsible for other websites’ contents it cannot control or the harms they may cause although it uses the connection they provided.

Ortadoğu Advertisement Presentation Publishing Tourism Education Architecture Industry and Trade Inc. may block the website to users in the following events:

-Information with wrong, incomplete, deceiving or immoral expressions is recorded to the website,

-Proclamation, advertisement, announcement, libelous expressions are used against natural person or legal identity,

-During various attacks to the website,

-Disruption of the website because of a virus.

Written, visual and audible materials of the website, including the code and the software are under protection by legal legislation.

Without the written consent of Ortadoğu Advertisement Presentation Publishing Tourism Education Architecture Industry and Trade Inc. the information on the website cannot be downloaded, changed, reproduced, copied, republished, posted or distributed.

All rights of the software and the design of the website belong to Ortadoğu Advertisement Presentation Publishing Tourism Education Architecture Industry and Trade Inc.

Ortadoğu Advertisement Presentation Publishing Tourism Education Architecture Industry and Trade Inc. will be pleased to hear your comments about our terms of use. Please share the subjects you think may enrich our website or if there is any problem regarding our website.

info@turkiyeklinikleri.com