The metabolic hormone adiponectin is secreted into the circulation by adipocytes and mediates key biological functions, including insulin sensitivity, adipocyte development, and fatty acid oxidation. Adiponectin is also abundant in saliva, where its functions are poorly understood. Here we report that murine taste receptor cells (TRCs) express specific adiponectin receptors and may be a target for salivary adiponectin. This is supported by the presence of all three known adiponectin receptors in transcriptomic data obtained by RNA-seq analysis of purified circumvallate (CV) taste buds. As well, immunohistochemical analysis of murine CV papillae showed that two adiponectin receptors, ADIPOR1 and T-cadherin, are localized to subsets of TRCs. Immunofluorescence for T-cadherin was primarily co-localized with the Type 2 TRC marker phospholipase C β2, suggesting that adiponectin signaling could impact sweet, bitter, or umami taste signaling. However, adiponectin null mice showed no differences in behavioral lick responsiveness compared with wild-type controls in brief-access lick testing. AAV-mediated overexpression of adiponectin in the salivary glands of adiponectin null mice did result in a small but significant increase in behavioral lick responsiveness to the fat emulsion Intralipid. Together, these results suggest that salivary adiponectin can affect TRC function, although its impact on taste responsiveness and peripheral taste coding remains unclear.

中文翻译：

---

小鼠中的味觉细胞表达激素脂联素的受体。

代谢激素脂连蛋白由脂肪细胞分泌到循环系统中，并介导关键的生物学功能，包括胰岛素敏感性，脂肪细胞发育和脂肪酸氧化。脂联素在唾液中也很丰富，其功能尚不清楚。在这里我们报告鼠味受体细胞（TRCs）表达特定的脂联素受体，可能是唾液脂联素的目标。通过转录组数据中存在的所有三个已知脂连蛋白受体的存在，这是通过纯化的环戊二酸（CV）味蕾的RNA序列分析获得的。同样，对小鼠CV乳头的免疫组织化学分析表明，两个脂联素受体ADIPOR1和T-钙粘着蛋白均位于TRC的子集。T-钙黏着蛋白的免疫荧光主要与2型TRC标记磷脂酶Cβ2共定位，提示脂联素信号传导可能会影响甜味，苦味或鲜味信号。但是，在短暂接触舔brief试验中，与野生型对照相比，无脂联素的小鼠在行为舔响应性方面没有差异。AAV介导的脂联素缺失小鼠唾液腺中脂联素的过表达确实导致行为上对脂肪乳脂内舔舔反应的小幅但显着增加。总之，这些结果表明，唾液脂联素可影响TRC功能，尽管其对味觉响应性和周围味觉编码的影响尚不清楚。AAV介导的脂联素缺失小鼠唾液腺中脂联素的过表达确实导致行为上对脂肪乳脂内舔舔反应的小幅但显着增加。总之，这些结果表明，唾液脂联素可影响TRC功能，尽管其对味觉响应性和周围味觉编码的影响尚不清楚。AAV介导的脂联素缺失小鼠唾液腺中脂联素的过表达确实导致行为上对脂肪乳脂内舔舔反应的小幅但显着增加。总之，这些结果表明，唾液脂联素可影响TRC功能，尽管其对味觉响应性和周围味觉编码的影响尚不清楚。