Mechanism of Upregulated Phagocytosis by miR-146a in Sjögren's Syndrome

Type of Submission


Campus Venue

Dixon Ministry Center, Alumni Hall


Cedarville, OH

Start Date

4-10-2013 1:00 PM

End Date

4-10-2013 5:00 PM



Sjögren's Syndrome (SJS) is an autoimmune disease characterized by autoimmune attack and damage of exocrine glands, especially salivary and lacrimal glands. The resulting apoptotlc cell death In these glands leads to severe dryness in the mouth and eyes. Previous research has shown that a microRNA, miR-146a, is upregulated in SjS patients compared to healthy individuals. Further investigation into the function of upregulated miR-146a suggested a role in upregulating phagocytosis. The goal of this study was to further elucidate the relationship between miR-146a ll1d phagocytosis. Our hypothesis states that miR-146a inhibits the effects of C1Q binding protein (C1 QBP) thus allowing C1Q to mark apoptotic cells thereby enhancing their phagocytosis. We first set out to develop a phagocytic assay that could be used to test this hypothesis. Apoptosis was induced in Jurkat cells by UV irradiation or etoposide treatment, and THP-1 monocytes were differentiated Into phagocytic macrophages. Apoptotic cells were labeled with propidium iodide, and phagocytic activity was measured using a fluorescent plate reader. C1QBP gene expression was analyzed in THP-1 cells by qRT-PCR. Using varied irradiation times, we determined the UV light was not strong enough to induce apoptosis in a reasonable amount of time. To resolve this, etoposide was used to effectively induce apoptosis in Jurkat cells. Significant phagocytosis of apoptotic Jurkats was observable. Next, qRT-PCR was used to analyze C1QBP gene expression in THP-1 cells. Our results indicate that either C1QBP was not expressed by THP-1 cells or the primers were not working properly. Further experiments are needed to resolve this issue. Optimization of a phagocytic assay to study the relationship between miR-146a and phagocytosis was successful and it will be utilized in future studies. C1QBP expression must first be established in THP-1 cells to test our hypothesis that C1QBP is the link between miR-146a and phagocytosis.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.


Apr 10th, 1:00 PM Apr 10th, 5:00 PM

Mechanism of Upregulated Phagocytosis by miR-146a in Sjögren's Syndrome

Cedarville, OH