Salt is crucial for survival, yet excessive intake of sodium chloride can have adverse effects. In the fruit fly, Drosophila melanogaster, internal taste organs located in the pharynx play a pivotal role in determining whether to accept or reject food. However, our understanding of how pharyngeal gustatory receptor neurons (GRNs) perceive high salt levels is still limited. In this study, we discovered that a specific member of the ionotropic receptor family, Ir60b, is selectively expressed in a pair of GRNs that respond to high salt concentrations. Through a two-way choice assay (DrosoX) to measure ingestion volume, we established that IR60b, along with two coreceptors, IR25a and IR76b, is necessary to deter excessive salt consumption. Interestingly, mutants lacking external taste organs but retaining internal taste organs in the pharynx showed significantly higher salt avoidance compared to flies missing all three IRs while still possessing all taste organs. These findings underscore the crucial role of IRs in pharyngeal GRNs in regulating the intake of high salt levels.

Mutations in the luteinizing hormone/chorionic gonadotropin receptors (LH/CGRs), representatives of the G protein-coupled receptor family, have been rapidly identified over the last 20 years. This review aims to compare and analyze the data reported the activating and inactivating mutations of the LH/CGRs between human, rat, equine and fish, specifically (Japanese eel Anguilla japonica). Insights obtained through detailed study of these naturally-occurring mutations provide a further update of structure-function relationship of these receptors. Specifically, we present a variety of data on eel LH/CGR. These results provide important information about LH/CGR function in fish and the regulation of mutations of the highly conserved amino acids in glycoprotein hormone receptors.

담즙산은 지방의 소화를 돕고 담즙의 배출을 용이하게 하는 역할을 하는 것으로 알려져 있었다. 하지만 여러 연구를 통해 담즙산에 대한 수용체가 존재하며 그 종류도 다양함을 알게 되었다. 담즙산 수용체는 담즙산 생리에 관여하는 것 외에도 에너지 대사, 염증 조절 등의 반응에 있어 인체 내에서 광범위하게 작용한다. GPBAR1과 S1PR2는 담즙산 수용체 중에서도 대표적인 G 단백질 결합수용체로서 담관세포에 많이 존재하며 세포의 증식 및 담즙 분비 등에 관여한다. 아울러 담관암의 진행과도 관련되어 있다는 연구가 발표되고 있어 향후 담관암 치료에 중요한 표적이 될 것으로 예상된다.

This study aimed to investigate whether neurotransmitter receptors in the nervous system were also expressed in oral keratinocytes. Expressions of various neurotransmitter receptor genes in immortalized mouse oral keratinocyte (IMOK) cells were examined by reverse transcriptase polymerase chain reaction. IMOK cells expressed calcitonin gene-related peptide (CGRP) receptor subunit genes Ramp1 and Ramp3 and glutamate receptor subunit genes Grina , Gria3 , Grin1 , Grin2a , and Grin2d . Moreover, IMOK cells expressed Adrb2 and Chrna5 that encode beta 2 adrenergic receptor and cholinergic receptor nicotinic alpha 5 for sympathetic and parasympathetic neurotransmitters, respectively. The expression of Bdkrb1 and Ptger4 , which encode receptors for bradykinin and prostaglandin E2 involved in inflammatory responses, was also observed at low levels. Expressions of Ramp1 and Grina in the mouse gingival epithelium were also confirmed by immunohistochemistry. When the function of neurotransmitter receptors expressed on IMOK cells was tested by intracellular calcium response, CGRP, glutamate, and cholinergic receptors did not respond to their agonists, but the bradykinin receptor responded to bradykinin. Collectively, oral keratinocytes express several neurotransmitter receptors, suggesting the potential regulation of oral epithelial homeostasis by the nervous system.

The CC chemokine receptor 5 (CCR5) is a G protein-coupled receptor that regulates chemotaxis and effector functions of immune cells. It also serves as the major co-receptor for the entry of human immunodeficiency virus (HIV). Recently, CCR5 inhibitors have been developed and used for the treatment or prevention of HIV infections. Additionally, it has been identified that CCR5 controls bone homeostasis by regulating osteoclastogenesis and the communication between osteoblasts and osteoclasts. However, the effects of CCR5 inhibition on bone tissue in elderly patients are unknown. This study aimed to examine the bone phenotype of aged CCR5 knockout (KO) mice. Femoral and tibial bones were isolated from 12-month and 18-month old wild-type (WT) and CCR5 KO mice, and microcomputed tomography and histology analyses were performed. Twelve-month-old CCR5 KO mice exhibited a decreased trabecular bone mass and cortical bone thickness in both femoral and tibial bones compared with agematched WT mice. Eighteen-month-old mice also showed a decreased trabecular bone mass in femurs compared with control WT mice, but not in tibial bones. Unlike in 12-month-old mice, the cortical margin of femurs and tibias in 18-month-old mice were rough, likely because they were aggravated by the deficiency of CCR5. Overall, our data suggest that the deficiency of CCR5 with aging can cause severe bone loss. When CCR5 inhibitors or CCR5 inactivating technologies are used in elderly patients, a preventive strategy for bone loss should be considered.

Chronic hypoxia is a major cause that increases neonatal mortality in the perinatal period. Vascular endothelial growth factor (VEGF) and its receptors induced by hypoxia are increased blood vessel permeability in the developing central nervous system and characterized as a critical factor in angiogenesis and vasculogenesis. This study investigated the development of the rat cerebellum with expression of VEGF and its receptors under chronic hypoxia in compare with normoxia. In addition, this study can contribute to the understanding of the effect development in the postnatal cerebellum. Rat pups were divided into two groups, normoxia and hypoxia group. The cerebellum of 35-day-old rat was removed and prepared for immunofluorescent staining. After staining, the sections were observed under the fluorescent microscope and were taken the picture using the microscopic-digital camera system. Expression of VEGF and Flk-1 restricted only to Purkinje cells, but feline sarcoma virus-like tyrosine kinase-1 (Flt-1) did not express in all of cerebellar layers. Under chronic hypoxia, expression of VEGF and fetal liver kinase-1 (Flk-1) increased in Purkinje cells but no changes in case of Flt-1. These results suggest that the source of VEGF and Flk-1 is Purkinje cells in the cerebellum. And increase of VEGF and Flk-1 expression in the murine cerebellum results from adaptive responses to chronic hypoxia.

The lutropin/chorionicgonadotropin receptor (LHR) is a member of the rhodopsin-like subfamily of G protein-coupled receptors (GPCRs) that have been shown to mediate the internalization of its five (activation: three; inactivation: two) naturally occurring mutation. Gonadotropin receptors are members of the seven transmembrane (TM) receptor families. Several point mutations in TM II, III, V and VI have been identified in the luteinizing hormone receptor (LHR) gene, leading to constitutive activation and inactivation of the receptor. In eelLHR, we generated 3 types of constitutive activating mutations (M410T, L469R and D590Y) and 2 types of constitutive inactivating mutations (D383N and Y546F) to investigate how they work on hormone-receptor interaction. To assess the functional effects of 5 receptor mutations directly, wild-type (WT) and mutant receptors were transiently expressed in CHO-K1 cells. We evaluated the basal and cAMP stimulation by rec-LH hormone. The activity was shown to be a dose-dependent increase in cAMP production in LHR-WT expressing cells with an EC50 of 24.3 ng/ml and basal cAMP level of 2.6 nM. However, three activation mutants (D590Y, L469R and M410T) was most elevated the basal cAMP response at 12.8, 21.7 and 6.1 nM, respectively. In two inactivation mutants (D383N and Y546F) are very low in the basal cAMP activation. The EC50 was also considerably decreased to 42.3 ng/ml and 1181 ng/ml, respectively.

후각 신경 시스템은 일반 생활 환경에서 많은 다양한 화학 물질을 인식하고 구별한다. 곤충에서는 다양한 화학 물질을 기호적 또는 회피적인 특이성을 부여하고 이를 구분해 낼 수 있는 고도로 발달된 후각신경 수용체들로 구성된 냄새 맡는 (odorant-gated) 이온 채널 군을 진화시켰다. 최근에 후각 수용체와 단백질을 포함한 olfaction 관련한 진딧물 게놈 밝혀졌고, 초파리에서 다양하게 분화되어 있는 후각 수용체들이 보고되고 있다. 후각 신경 수용체의 유전체는 매우 높은 보전적인 염기 서열을 가지고 있으며, 체계적인 신호 전달 시스템을 갖추고 있다. 대표적 수용체인 odorant-gated ion channels comprised of a highly conserved co-receptor (Orco)는 중심 구멍 주위에 대칭 적으로 배열된 4 개의 서브 유닛을 갖는 homotetramer 채널 구조를 가지고 있다. 이는 인체 내에 존재하는 7-transmembrane receptor와 매우 유사한 구조를 형성하고 있고, 신경전달물질의 수용체와 매우 유사한 구조적 형태 및 gating mechanism을 가지고 있다. 본 연구에서는 초파리에서 분리한 후각 신경 수용체 하위 유형인 OR65 유전자 분리하여 세포 발현 시켜 Xenopus oocyte를 이용하여 Whole cell voltage clamp recording을 실시하였다. 본 수용체의 성공적인 발현 이후 유해 해충 유인제 개발 회사인 마이크로자임의 미생물 배양 추출물을 이용해서 후각 신경 수용체 활성 조절 여부를 연구하였다. 미생물 배양 추출물을 10,000배 희석한 recording media에서 수용체의 활성을 확인하였고, 이를 농도 별로 처리하여 농도 의존성 수용체 활성 작용을 확인하였다. 따라서 곤충의 후각 신경 수용체 활성 조절 시스템을 이용하여 유인물질 또는 기피 물질을 발굴할 수 있으며, 본 연구를 통해서 MZ01은 곤충 수용체 OR65를 활성 시킴으로써 유인 현상을 나타내며, 본 연구를 통해서 현장에서 검증된 미생물 배양 추출물의 성능을 과학적 분석으로 결과를 제시하였다.

To formulate folate receptor (FR)-specific graphene-based electrochemical electrodes, a folic acid (FA) derivative attached with two pyrene molecules on the glutamate tail of FA was synthesized. The resulting pyrene-functionalized FA (FA-Py) presented the spontaneous noncovalent binding on chemically reduced graphene oxides (rGO) through an π-π interaction. Ultrathin morphology, high water-resistance, and preservation of intact FR-specific pteroates from the rGO/FA-Py assembly allow this assembly to be exploited as robust and FR-specific electrochemical electrode materials. The limits of detecting rGO/FA-Py modified electrodes were found to be as low as 3.07 nM in FR concentrations in cyclic voltammetry analysis.

G protein-coupled receptors (GPCRs) belong to cell membrane protein family, which regulate various physiological process such as reproduction, behavior and immune etc. In other to identify the GPCRs in pheromone gland of Maruca vitrata, we carried out transcriptome analysis from both females. Transcriptome analysis in the pheromone gland yielded approximately 22Gb and 47,528 transcripts showed positive FPKM value. 48 Genes involved in GPCRs were identified such as pheromone biosynthesis activating neuropeptide receptor (PBANr), prostaglandin receptors, neuropeptide receptor, 5-hydroxytryptamine receptor, galanin receptor, calcitonin gene-related peptide receptor, diuretic hormone receptor, gonadotropin-releasing hormone receptor, frizzled and orphan receptors, etc. Various expression of GPCRs in the pheromone gland indicates the role of pheromone gland may not be limited to the production of pheromone.

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 Ca2+ imaging of acinar cells are necessary for understanding the Tas2r108 functions.

Pro-inflammatory cytokines, interleukin-1β (IL1B), IL6, and tumor necrosis factor-alpha (TNF), are known to play important roles in regulating the endometrial function in the uterus during the estrous cycle and pregnancy in several species. However, the expression and function of these cytokines and their receptors in the uterine endometrium during the estrous cycle have not been studied in pigs. Thus, this study determined the expression and regulation of IL1B, IL6, TNF and their respective receptors, IL1R1, IL1RAP, IL6R, GP130, TNFRSF1A, and TNFRSF1B during the estrous cycle in pigs. To analyze levels of each gene expression in the uterine endometrium we obtained from endometrial tissues on Days 0, 3, 6, 9, 12, 15, and 18 of the estrous cycle. Real-time RT-PCR analysis showed that levels of IL1B, IL1RAP, IL6R, GP130, TNF, TNFRSF1A, and TNFRSF1B mRNAs were highest on Day 15 or 18 of the estrous cycle, which corresponds to the proestrus period. Levels of IL1R1 were highest on Day 0, while levels of IL6 were biphasic with high levels on Day 6 and Day 15. The abundance of IL1B, IL6, IL6R, and TNF mRNAs was decreased by progesterone, while levels of GP130 were increased by progesterone in endometrial tissue explants. These results showed that expression of pro-inflammatory cytokines and their receptors changed stage-specifically during the estrous cycle and regulated by progesterone in the uterine endometrium in pigs, suggesting that these pro-inflammatory cytokines may be involved in the regulation endometrial function during the estrous cycle in pigs.

Progesterone regulates endometrial functions to support implantation, placentation, and fetal/placental development in the uterus. It is known that actions of progesterone are mediated by nuclear progesterone receptor (PGR), using the signaling pathway referred to the genomic pathway. However, all physiological progesterone actions cannot be explained by the genomic pathway via PGR, and it is understood that there are non-genomic actions of progesterone though membrane progesterone receptors, progesterone receptor membrane components (PGRMCs) and progestin and adipoQ receptors (PAQRs). The expression and localization of PGRMCs and PAQRs has been reported in female reproductive tissues of several species such as human, mouse and cattle. Previously, we have shown that PGRMCs and PAQRs are expressed in the porcine uterine endometrium during the estrous cycle and pregnancy. However, the regulatory mechanism for expression of PGRMCs and PAQRs in the uterine endometrium has not been studied in pigs. Thus, to understand the regulatory mechanism of PGRMC1, PGRMC2, PAQR5, PAQR6, PAQR7, PAQR8, and PAQR9 expression in the uterine endometrium during the estrous cycle and pregnancy in pigs, we determined the effect of steroid hormones estrogen and progesterone on expression of PGRMCs and PAQRs using the endometrial tissue explants for immature pigs. Levels of PGRMC1, PGRMC2, PAQR5, PAQR6, PAQR7, PAQR8, and PAQR9 mRNAs were increased by increasing doses of progesterone, but not by estradiol in the uterine endometrium. Blocking PGR by treatment of RU486, a progesterone receptor antagonist, increased levels of endometrial PGRMCs and PAQRs mRNA. These data showed that membrane progesterone receptors were induced by progesterone in the uterine endometrium, suggesting that these membrane progesterone receptors may play an important role in mediating progesterone actions in the uterine endometrium for regulation of the estrous cyclicity and pregnancy. [Supported by the Next Generation Biogreen 21 Program (# PJ01119103), Rural Development Administration, Republic of Korea]

One of the overlooked points in mosquito blood feeding research is a final step before blood feeding. We provide the anatomical and chemosensory evidence that a piercing structure of the mouthpart of the mosquitoes is an essential apparatus for the penultimate stage in blood feeding in mosquitoes. Indeed, the stylet possesses a number of sensory hairs located at the tip of the stylet. These hairs house olfactory receptor neurons that express two conventional olfactory receptors of Aedes aegypti (AaOrs), AaOr8 and AaOr49, together with the odorant co-receptor (AaOrco). In vivo calcium imaging using transfected cell lines demonstrated that AaOr8 and AaOr49 were activated by volatile compounds present in blood. Taken together, we identified olfactory receptor neurons in the stylet involved in mosquito blood feeding behaviors, which in turn indicates that olfactory perception in the stylet is necessary and sufficient for mosquitoes to find host blood in order to rapidly acquire blood meals from a host animal.