The Expression Of GPR30in The Vocal Fold

[Objective]The sex hormone levels fluctuate with the menstrual cycle, which may have some implications to the change of the women voice. It was reported that nearly1/3of women of childbearing age would experience the premenstrual voice syndrome, which is characterized by vocal fatigue, decreased range, a loss of power and loss of certain harmonics, and edema, vascular congestion and inflammation of the vocal mucosa could be detected under the laryngoscope. Animal studies revealed the same results, which indicated that the deficiency of E2could cause congestion, edema and inflammation of the rat larynx mucosa. It is unclear yet how E2affects the vocal fold during the menstrual cycle. Some studies revealed a relatively low positive rat of ER expression in vocal fold. However, most studies suggested that no estrogen receptors (ERs) could be measured in the vocal fold. The G-protein coupled estrogen receptor (GPER, GPR30), which could combine with E2specifically and mediate some rapid and nongenomic effects, has been revealed as a new estrogen receptor recently. Many tissues of human were suggested to express GPR30, which could protect the body from injury by inhibiting the inflammatory response in some pathological process. Thus we presumed that GPR30could exist and may also be involved in the E2-mediated inflammatory process in the VF, causing the transient mucosa edema, congestion as well as inflammatory in the VF of women during the menstrual cycle with the physiological fluctuation of hormones. So this study aimed at understanding the expression of GPR30in human and rat vocal fold tissue and its possible significance,[Methods]The vocal fold tissues of rat and human vocal benign diseases and sections without infiltration of tumor cells from laryngectomy were collected. Reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) were used to detect the distribution of GPR30in the VF tissues. Associations between GPR30expression and pathological categories, ages as well as genders were evaluated using the x2test or the Fisher’s exact test if needed. The probable role of GPR30in the inflammation process of the vocal fold due the E2fluctuation was analyzed according to the recent literature.[Results]:1. GPR30mRNA could be detected in all rat vocal fold specimens (n=12), while19out of29VF samples presented GPR30mRNA positive.2. The immunohistochemistry results showed that the GPR30protein expression could be determined in the epithelium in34out of63VF samples. The subcellular location could be in the membrane, cytoplasm and nucleus.3. The distribution of GPR30in different VF pathological types:(1)5out of9peri-tumoral VF sections (55.6%) from laryngectomy and14out of20(70%) benign VF lesion tissues were GPR30mRNA positive.(2) The IHC results showed that14out of23cases (60.9%) including both leukoplakia and peri-tumoral VF samples, and20out of40(50%) benign VF diseases were revealed to express GPR30protein.4. The subcellular location of GPR30:(1) GPR30was mainly located to the membrane of the epithelium of benign VF lesions, and the nuclear staining could also be detected in some cases. The immune-staining of GPR30in VF tissues without tumor cells infringed presented a dominant nuclear staining in the epithelial. No positive staining could be measured in the lamina propria or the muscle layer of the VF tested.5. No statistical significant differences were detected that were associated to gender as well as age in GPR30distribution in benign VF tissues, although they could be measured.[Conclusion]:1. We firstly found that GPR30located both in human and rat VF tissues by Rt-PCR and immunohistochemistry.2. GPR30was located in the epithelial layer of the vocal fold, but not in the lamina propria or the muscle layer. Moreover, the subcellular location of GPR30differed among VF pathologies. The BVFDs mainly showed a membrane staining, while the PTVFs and the VF leukoplakia showed a dominant nuclear staining.3. GPR30could be involved in the vocal fold inflammation mediated by the E2fluctuation in women during the menstrual cycle.