OZET: Osteoartrit (OA) yaygin olarak gorulen onemli bir eklem hastaligidir ve klinik olarak tedavisi tam olarak mumkun degildir. Eklem kikirdagindaki doku homeostazinin bozulmasi sonucu ortaya cikan OA’nin molekuler patofizyolojisinde biyokimyasal, metabolik ve genetik faktorlerin rol oynadigi dusunulmekte ancak etki mekanzimasi halen tam olarak bilinmemektedir. Kikirdak homeostazini kontrol eden ekstraselluler duzenleyicilerin ve intraselluler sinyal mekanizmalarin anlasilmasi OA icin yeni terapotik hedeflerin tanimlanmasina katki saglayacaktir. Son zamanlarda, kucuk kodlamayan RNA’larin bir sinifi olan mikroRNA (miRNA)’larin gelisim, homeostaz ve bagisiklik fonksiyonlarinda onemli rol oynadigi ve miRNA’larin kanserden inflamasyona kadar cogu hastalikla iliskili oldugu gosterilmistir. mRNA yikilmasi veya translasyon baskilanmasi ile gen ekspresyonunu duzenleyen miRNA’larin, cesitli hastaliklardaki rollerinin ogrenilmesi onlarin yeni bir biyobelirtec olarak degerlendirilmesine yol acmaktadir. miRNA’larin ekpresyonlarinin hucre kaderinin belirlenmesindeki onemli rolu disinda, ozel immun cevabi ve inflamatuar uyariyi da duzenledikleri belirlenmistir. Eklem kikirdaginda miRNA ekspresyonlarinin arastirilmasi OA gibi hastaliklarda hedeflerin tanimlanmasina imkan saglayabilecektir. Eklem hasari veya tamiri sirasinda cesitli biyobelirtecler meniskus ve ligamentler, eklem kikirdagi, kemik doku, osteofitler ve sinoviyal zardan salinarak sinoviyal sivi havuzuna ve buradan da lenfatik dolasima ve sistemik dolasima katilmaktadir. Bu biyobelirteclerin serum, idrar veya kanda belirlenmesi, OA’nin erken donemde saptanmasi, hastaligin seyrinin ve tedaviye cevabinin izlenmesi icin onemlidir. Bu nedenlerle yapilan calismalarda, OA mekanizmasinin anlasilmasina katki saglamak icin yeni bir terapotik hedef olan miRNA’larin OA patofizyolojisindeki rollerinin belirlenmesi amaclanmaktadir. Bu derlemede post-transkripsiyonal duzenlemede gorevli miRNA’larin, OA’nin molekuler mekanizmasindaki rolleri incelenmektedir. Ozet olarak, miRNA’larin tani ve tedavide onemli potansiyele sahip olabilecegi ve OA’nin tedavi edilmesi icin yeni bir yol saglayabilecegi onerilmektedir. ANAHTAR KELIMELER: Osteoartrit, mikroRNA MicroRNAs AND OSTEOARTHRITIS ABSTRACT: Osteoarthritis (OA) is most common musculoskeletal disorder and its full treatment is not possible clinically. The pathogenesis of OA involves the degradation of tissue homeostasis in articular cartilage, but many of the underlying biochemical, metabolic and genetic factors remain largely unknown. Understanding the extracellular regulators and the intracellular signaling mechanisms controlling the cartilage homeostasis will contribute to the identification of new therapeutic targets for OA. Recently, it is shown that microRNAs (miRNAs), which are a sub-group of small non-coding RNAs, play an important role in terms of development, homeostasis and immunity functions; and that miRNAs are connected to several diseases from cancer to inflammation. miRNAs regulating gene expression with mRNA degradation or suppression of translation have roles in various diseases causes them to be evaluated as a new biomarker. It was found out that miRNAs regulate specific immune response and inflammatory stimuli, in addition to their important role in determination of a cell’s fate. Investigation of miRNA expression in the articular cartilage can make the identification of targets in diseases such as OA possible. During joint’s damage and repair, various biomarkers from meniscus and ligaments, articular cartilage, bone tissue, osteophytes and synovial membrane are secreted into the synovial fluid pool and are passed from there to lymphatic and systemic circulations. Identification of these biomarkers in serum, urine or blood is important for early detection of OA and for monitoring the course of the disease and its response to treatment. For these reasons, it was aimed to determine miRNAs’ role, in the pathophysiology of OA as a new therapeutic target in order to contribute to the understanding of OA’s mechanism of action in the studies carried out. In this review, the current evidence of the role of miRNAs in charge of post-transcriptional regulation, which is playing in molecular mechanisms underlying development and progression of OA, has been summarized. In summary, it is proposed that miRNAs have an important potential in terms of diagnosis and treatment of OA and that they can provide a new way for treatment of OA. KEYWORDS: Osteoarthritis, microRNA