| 1456 Differential Expression of Mucins in Human Salivary Glands | ||
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L. BRUNO, J. TOLOSA, B. REBOUCAS, J. ZHANG, X. LI, F.G. OPPENHEIM, and G.D. OFFNER, Boston University Medical Center, MA, USA The high molecular weight salivary mucin, MG1, found in human submandibular/ sublingual gland secretion (HSMSL), has been thought to be comprised primarily of the MUC5B gene product. However, several recent reports have suggested that another gel-forming mucin, muc19, is the major gel-forming mucin secreted by mouse sublingual gland. Objective: The objective of this study was to determine whether MUC19 transcripts could be detected in human salivary gland tissues and to determine the relative expression levels of MUC5B and MUC19 in submandibular and sublingual glands. Methods: Human submandibular and sublingual gland cDNAs were amplified by PCR using mucin specific primers and the products examined on agarose gels. Quantitative expression levels of the two mucins were then determined by real-time PCR and the results normalized to levels of beta actin in the same samples. Results: By RT-PCR, MUC5B transcripts were more abundant in the sublingual gland than in the submandibular gland while MUC19 transcripts were more abundant in the submandibular gland. Real-time PCR confirmed these results and showed that the sublingual gland contained MUC5B transcripts at a level approximately 30 times greater than the level of MUC19 transcripts while the submandibular gland contained MUC19 transcripts at a level approximately 4 times greater than the level of MUC5B transcripts. Conclusion: While it has yet to be determined if the MUC19 gene product is a component of MG1, it appears that transcripts for the two gel forming mucins MUC5B and MUC19 are differentially expressed in human salivary glands. In addition, MUC19 transcripts were found to be more abundant in the human submandibular gland, while in the mouse, muc19 is expressed exclusively in the sublingual gland. This suggests that MUC5B and MUC19 may have evolved to perform distinct functions in the oral cavity. Supported by NIH NIDCR grants DE11691, DE14080 and DE07652. | ||
| Seq #177 - Keynote Address and Salivary Mucins 10:45 AM-12:15 PM, Friday, March 23, 2007 Ernest N. Morial Convention Center 290 | ||
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