Research

The sense of taste is perceived by lingual sensory organ, tongue. The tongue comes in contact with a myriad of consumables and orchestrate decisions to reject or ingest. Mammalian tongue comprises several taste organs called papillae and have resident taste buds (TB). In addition, large area of tongue is covered by non-taste organ that have roles in eating and manipulating the food bolus. The anterior tongue includes a patterned array of taste fungiform papillae (FP) surrounded by non-taste filiform papillae (FILIF). The posterior tongue includes a single circumvallate (CV) papilla in rodent and unlike FP, includes 100s of TB. The taste bud is further heterogeneous and include different cell types to recognize the 5 taste stimulus, salt, sour, sweet, bitter and umami. The tongue and taste organs are innervated from three cranial ganglia: the trigeminal, geniculate, and petrosal. The trigeminal ganglion (Vth) innervates the anterior tongue, FP, and FILIF via the lingual nerve. The geniculate ganglion (VIIth) via chorda tympani provides innervation only to TB in the anterior tongue. The petrosal ganglion (IXth) neurons innervate TB on the posterior tongue, via the glossopharyngeal nerve.

Maintenance of the specialized taste papillae/TB structures is controlled by signaling networks within the tongue epithelium, and between the epithelium and nerves or underlying connective tissue core. We know that Hedgehog (HH) signaling is involved in development and maintenance of taste papillae (FP and CV) and TB (reviewed in Mistretta and Kumari, 2017). HH signaling has several components including cell surface receptors to cytosolic and nuclear activators. However, much of the published work has emphasized roles of the GLI transcription factors. My current research is focused on determining expression of different HH pathway components and their function in tongue.

In addition, the regulatory pathways associated with tongue homeostasis and genes responsible for FP/TB alteration after HH pathway inhibiting drugs are not clearly understood and remain challenging to understand tongue and taste physiology in response to therapeutic interventions such as HH signaling blockade. Therefore, utilizing advance transcriptome and proteomics tools I plan to focus my research on identification of genes and associated signaling pathways involved in regulation of tongue epithelium. I see my research as a part of a broad effort in the cell and molecular sciences to understand the taste system in the context of human disease and treatments.