• 한국수산과학회지
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• 제38권3호
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• pp.158-163
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• 2005

This paper deals with the histology of the barbels of striped sea catfish, Plotosus lineatus (Thunberg). This fish have eight noticeable barbels of two pairs on their maxillary and mandibular. Each barbel is composed of an epidermis, dermis and a central rod of cartilage. The epidermis in the middle part of the maxillary barbel is thicker than those on other parts, and formed of stratified epithelium which contains many cutaneous taste buds and a few small club cells. Number of taste buds increase on the middle and posterior part of each barbel. The dermis consists of loose connective tissue fibers which encloses blood vessels and bundles of nerve fibers. The barbels of this fish can be categorized into stiff and flexible types and are accessory, feeding and sensory structures. Thus we substantiate that they are gustatory receptor organs for this fish.

• 한국수산과학회지
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• 제39권4호
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• pp.338-343
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• 2006

Histological observations of the barbels of torrent catfish (Amblycipitidae) in Korea are reported. The bullhead torrent catfish (Liobagrus andersoni) and Korean torrent catfish (L. obesus) have eight obvious barbels in two pairs each on the maxilla and mandible. Each barbel is composed of an epidermis, dermis, and central cartilagerod. The epidermis of the maxillary and mandibular barbels of the bullhead torrent catfish is thicker than that of the Korean torrent catfish (P<0.05) and is formed of stratified epithelium that contains many cutaneous taste buds and a few small club cells. There are many taste buds on the upper part of each barbel. The dermis consists of loose connective tissue fibers that enclose blood vessels and bundles of nerve fibers. The barbels of these fish can be categorized into stiff and flexible types and are accessory, feeding, and sensory structures. Our results validate the barbels as gustatory receptor organs for these fishes.

• International Journal of Oral Biology
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• 제43권1호
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• pp.5-11
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• 2018

Recent findings indicate that Type 2 taste receptors (T2Rs) are expressed outside the gustatory system, including in the gastrointestinal tracts and the exocrine glands, such as the submandibular (SM), parotid (P), lacrimal (L) glands and pancreas (PC). Specifically, T2Rs are found in some of the gastrointestinal endocrine cells, and these cells secreted peptide hormones in response to stimulation by bitter-tasting compounds. The results show that T2Rs may have significant physiological roles besides bitter taste reception. The functions of the T2Rs in the exocrine glands remain poorly understood. An expression levels analysis of T2Rs will help to determine those functions in the exocrine glands. The expression levels of the T2Rs in the exocrine glands were discovered via the qPCR. C57BL/6J mice of 42~60-day-old were used. Messenger RNAs were extracted from S, P, L and PC. Cloned DNAs were synthesized by reverse transcription. Quantitative PCRs were performed using the SYBR Green method. The expression levels of the T2Rs were calculated as relative expression levels to that of the GAPDH. The statistical significance among the observed exocrine glands was tested using the variance analysis (ANOVA test). Tas2r108, out of murine 35 T2Rs, was the most highly expressed in every observed exocrine gland. This finding was similar to previous results from tongue papillae, but the expression levels were lower than those of the tongue papillae. Tas2r137 of SM, P, L and PC were expressed a little lower than that of tongue papillae. The T2Rs in the exocrine glands may play slightly different roles from those in the tongue. We suggest that physiological studies such as a patch clamp and functional $Ca^{2+}$ imaging of acinar cells are necessary for understanding the Tas2r108 functions.

• Molecules and Cells
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• 제38권10호
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• pp.911-917
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• 2015

Citronellal, a well-known plant-derived mosquito repellent, was previously reported to repel Drosophila melanogaster via olfactory pathways involving but not directly activating Transient Receptor Potential Ankyrin 1 (TRPA1). Here, we show that citronellal is a direct agonist for Drosophila and human TRPA1s (dTRPA1 and hTRPA1) as well as Anopheles gambiae TRPA1 (agTRPA1). Citronellal-induced activity is isoform-dependent for Drosophila and Anopheles gambiae TRPA1s. The recently identified dTRPA1(A) and ag-TRPA1(A) isoforms showed citronellal-provoked currents with EC50s of $1.0{\pm}0.2$ and $0.1{\pm}0.03mM$, respectively, in Xenopus oocytes, while the sensitivities of TRPA1(B)s were much inferior to those of TRPA1(A)s. Citronellal dramatically enhanced the feeding-inhibitory effect of the TRPA1 agonist N-methylmaleimide (NMM) in Drosophila at an NMM concentration that barely repels flies. Thus, citronellal can promote feeding deterrence of fruit flies through direct action on gustatory dTRPA1, revealing the first isoform-specific function for TRPA1(A).

• Nutrition Research and Practice
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• 제16권1호
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• pp.1-13
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• 2022

BACKGROUND/OBJECTIVES: Bitter taste receptors are taste signaling pathway mediators, and are also expressed and function in extra-gustatory organs. Skin aging affects the quality of life and may lead to medical issues. The purpose of this study was to better understand the anti-skin aging effects of bitter taste receptors in D-galactose (D-gal)-induced aged human keratinocytes, HaCaT cells. MATERIALS/METHODS: Expressions of bitter taste receptors in HaCaT cells and mouse skin tissues were examined by polymerase chain reaction assay. Bitter taste receptor was overexpressed in HaCaT cells, and D-gal was treated to induce aging. We examined the effects of bitter taste receptors on aging by using β-galactosidase assay, wound healing assay, and Western blot assay. RESULTS: TAS2R16 and TAS2R10 were expressed in HaCaT cells and were upregulated by D-gal treatment. TAS2R16 exerted protective effects against skin aging by regulating p53 and p21, antioxidant enzymes, the SIRT1/mechanistic target of rapamycin pathway, cell migration, and epithelial-mesenchymal transition markers. TAS2R10 was further examined to confirm a role of TAS2R16 in cellular senescence and wound healing in D-gal-induced aged HaCaT cells. CONCLUSIONS: Our results suggest a novel potential preventive role of these receptors on skin aging by regulating cellular senescence and wound healing in human keratinocyte, HaCaT.