Thaindian News

Washington, June 3 (IANS) Researchers are one step closer to unravelling why salivary glands stop working because of disease or damage from treatment of diseases.

Salivary glands are essential for lubrication, defence and beginning digestion in the mouth. The largest of the salivary glands, the parotid, secretes important proteins into the saliva.

Douglas Darling, professor in oral health and rehabilitation at the University of Louisville School of Dentistry, and his team have identified a protein sorting mechanism used by the salivary gland.

The discovery could open the way to advanced therapies for patients with damaged or dysfunctional salivary glands because of radiation therapy, prescription drugs or Sjogren’s Syndrome, defined by two most common symptoms - dry eyes and a dry mouth.

As with all salivary glands, the parotid has multiple secretion pathways. Therefore, it must sort proteins destined for saliva into the correct pathway for secretion. This can be tricky as there are seven possible pathways, reports the Journal of Dental Research.

One pathway takes proteins to the salivary duct, other pathways carry different proteins to the ‘back’ side of the cell to be secreted into the blood or to form a supportive matrix for the cells.

Transport along these pathways occurs by sorting the proteins into vesicles (hollow membrane sacs) that carry their “cargo” to the correct destination, according to a Louisville statement.

Conventional thought was that cargo proteins are moved into the forming vesicles by attaching to sorting receptor proteins.

Darling and his team suggest the reason no salivary sorting receptor protein has been found is that it may not exist.