Extracellular loop 3 (EL3) and EL3-proximal transmembrane helix 7 of the mammalian type I and type II gonadotropin-releasing hormone (GnRH) receptors determine differential ligand selectivity to GnRH-I and GnRH-II.

Li, Jian Hua,Choe, Han,Wang, Ai Fen,Maiti, Kaushik,Wang, Chengbing,Salam, Abdus,Chun, Sang Young,Lee, Won-Kyo,Kim, Kyungjin,Kwon, Hyuk Bang,Seong, Jae Young American Society for Pharmacology and Experimental 2005 Molecular pharmacology Vol.67 No.4

<P>Mammalian type I and II gonadotropin-releasing hormone (GnRH) receptors (GnRHRs) show differential ligand preference for GnRH-I and GnRH-II, respectively. Using a variety of chimeric receptors based on green monkey GnRHR-2 (gmGnRHR-2), a representative type II GnRHR, and rat GnRHR, a representative type I GnRHR, this study elucidated specific domains responsible for this ligand selectivity. A chimeric gmGnRHR-2 with the extracellular loop 3 (EL3) and EL3-proximal transmembrane helix 7 (TMH7) of rat GnRHR showed a great increase in ligand sensitivity to GnRH-I but not to GnRH-II. Point-mutation studies indicate that four amino acids, Leu/Phe(7.38), Leu/Phe(7.43), Ala/Pro(7.46), and Pro/Cys(7.47) in TMH7 are critical for ligand selectivity as well as receptor conformation. Furthermore, a combinatory mutation (Pro(7.31)-Pro(7.32)-Ser(7.33) motif to Ser-Glu-Pro in EL3 and Leu(7.38), Leu(7.43), Ala(7.46), and Pro(7.47) to those of rat GnRHR) in gmGnRH-2 exhibited an approximately 500-fold increased sensitivity to GnRH-I, indicating that these residues are critical for discriminating GnRH-II from GnRH-I. [Trp(7)]GnRH-I and [Trp(8)]GnRH-I but not [His(5)]GnRH-I exhibit a higher potency in activating wild-type gmGnRHR-2 than native GnRH-I, indicating that amino acids at positions 7 and 8 of GnRHs are more important than position 5 for differential recognition by type I and type II GnRHRs. As a whole, these data suggest a molecular coevolution of ligands and their receptors and facilitate the understanding of the molecular interaction between GnRHs and their cognate receptors.</P>

Microarray Analysis of Long Non-coding RNA Expression Profile Associated with 5-Fluorouracil-Based Chemoradiation Resistance in Colorectal Cancer Cells

Xiong, Wei,Jiang, Yong-Xin,Ai, Yi-Qin,Liu, Shan,Wu, Xing-Rao,Cui, Jian-Guo,Qin, Ji-Yong,Liu, Yan,Xia, Yao-Xiong,Ju, Yun-He,He, Wen-Jie,Wang, Yong,Li, Yun-Fen,Hou, Yu,Wang, Li,Li, Wen-Hui Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Background: Preoperative 5-fluorouracil (5-FU)-based chemoradiotherapy is a standard treatment for locally advanced colorectal cancer (CRC). However, CRC cells often develop chemoradiation resistance (CRR). Recent studies have shown that long non-coding RNA (lncRNA) plays critical roles in a myriad of biological processes and human diseases, as well as chemotherapy resistance. Since the roles of lncRNAs in 5-FU-based CRR in human CRC cells remain unknown, they were investigated in this study. Materials and Methods: A 5-FU-based concurrent CRR cell model was established using human CRC cell line HCT116. Microarray expression profiling of lncRNAs and mRNAs was undertaken in parental HCT116 and 5-FU-based CRR cell lines. Results: In total, 2,662 differentially expressed lncRNAs and 2,398 mRNAs were identified in 5-FU-based CRR HCT116 cells when compared with those in parental HCT116. Moreover, 6 lncRNAs and 6 mRNAs found to be differentially expressed were validated by quantitative real time PCR (qRT-PCR). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis for the differentially expressed mRNAs indicated involvement of many, such as Jak-STAT, PI3K-Akt and NF-kappa B signaling pathways. To better understand the molecular basis of 5-FU-based CRR in CRC cells, correlated expression networks were constructed based on 8 intergenic lncRNAs and their nearby coding genes. Conclusions: Changes in lncRNA expression are involved in 5-FU-based CRR in CRC cells. These findings may provide novel insight for the prognosis and prediction of response to therapy in CRC patients.

Crocin alleviates neurotoxicity induced by bupivacaine in SH-SY5Y cells with inhibition of PI3K/AKT signaling

Lin Lili,Chen Zhen,Li Jun,Peng Jianye,Wang Jian,Feng Mingjun,Liu Tiancheng,Zhang Mengli,Wu Xian,Ai Fen,Shen Caijie 한국유전학회 2024 Genes & Genomics Vol.46 No.1

Background Bupivacaine, a common local anesthetic, can cause neurotoxicity and permanent neurological disorders. Crocin has been widely reported as a potential neuroprotective agent in neural injury models. Objective The aim of this study was to investigate the role and regulatory mechanism of crocin underlying bupivacaine-induced neurotoxicity. Method Human neuroblastoma SH-SY5Y cells were treated with bupivacaine and/or crocin for 24 h, followed by detecting cell viability using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. The effect of crocin or bupivacaine on SH-SY5Y cell proliferation was measured by Ki67 immunofluorescence assay. The levels of apoptosis-related proteins and the markers in the PI3K/Akt signaling pathway were examined using western blot analysis. The activities of caspase 3, catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were tested using respective commercial assay kits. Flow cytometry analysis was executed for detecting SH-SY5Y cell apoptosis. Result Crocin attenuated bupivacaine-induced neurotoxicity in SH-SY5Y cells. Meanwhile, crocin inhibited SH-SY5Y cell apoptosis induced by bupivacaine via repressing the activity of caspase-3, reducing Bax expression, and elevating Bcl-2 expression. Moreover, crocin mitigated oxidative stress in SH-SY5Y cells by increasing the content of CAT, SOD, GSH-Px and reducing the content of MDA. Additionally, crocin protected against bupivacaine-induced dephosphorylation of Akt and GSK-3β. The protective effects of crocin against bupivacaine-induced neurotoxicity in SH-SY5Y cells were counteracted by the Akt inhibitor. Conclusion These results suggested that crocin may exert a neuroprotective function by promoting cell proliferation and suppressing apoptosis and oxidative stress in SH-SY5Y cells. Thus, crocin might become a promising drug for the treatment of bupivacaine-induced neurotoxicity. Background Bupivacaine, a common local anesthetic, can cause neurotoxicity and permanent neurological disorders. Crocin has been widely reported as a potential neuroprotective agent in neural injury models. Objective The aim of this study was to investigate the role and regulatory mechanism of crocin underlying bupivacaine-induced neurotoxicity. Method Human neuroblastoma SH-SY5Y cells were treated with bupivacaine and/or crocin for 24 h, followed by detecting cell viability using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. The effect of crocin or bupivacaine on SH-SY5Y cell proliferation was measured by Ki67 immunofluorescence assay. The levels of apoptosis-related proteins and the markers in the PI3K/Akt signaling pathway were examined using western blot analysis. The activities of caspase 3, catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were tested using respective commercial assay kits. Flow cytometry analysis was executed for detecting SH-SY5Y cell apoptosis. Result Crocin attenuated bupivacaine-induced neurotoxicity in SH-SY5Y cells. Meanwhile, crocin inhibited SH-SY5Y cell apoptosis induced by bupivacaine via repressing the activity of caspase-3, reducing Bax expression, and elevating Bcl-2 expression. Moreover, crocin mitigated oxidative stress in SH-SY5Y cells by increasing the content of CAT, SOD, GSH-Px and reducing the content of MDA. Additionally, crocin protected against bupivacaine-induced dephosphorylation of Akt and GSK-3β. The protective effects of crocin against bupivacaine-induced neurotoxicity in SH-SY5Y cells were counteracted by the Akt inhibitor. Conclusion These results suggested that crocin may exert a neuroprotective function by promoting cell proliferation and suppressing apoptosis and oxidative stress in SH-SY5Y cells. Thus, crocin might become a promising drug for the treatment of bupivacaine-induced neurotoxicity.

GnRH-II Analogs for Selective Activation and Inhibition of Non-Mammalian and Type-II Mammalian GnRH Receptors

Jae Young Seong,Kaushik Maiti,Jian Hua Li,Ai Fen Wang,Sujata Acharjee,Wang Phil Kim,임욱빈,권혁방 한국분자세포생물학회 2003 Molecules and cells Vol.16 No.2

ecently, we identified three types of non-mammalian gonadotropin-releasing hormone receptors (GnRHR) in the bullfrog (designated bfGnRHR-1-3), and a mammalian type-II GnRHR in green monkey cell lines (denoted gmGnRHR-2). All these receptors responded better to GnRH-II than GnRH-I, while mammalian type-I GnRHR showed greater sensitivity to GnRH-I than GnRH-II. In the present study, we designed new GnRH-II analogs and examined whether they acti- vated or inhibited non-mammalian and mammalian type-II GnRHRs. [D-Ala 6 ]GnRH-II, with D-Ala substi- tuted for Gly 6 in GnRH-II, increased inositol phos- phate (IP) production in cells stably expressing non- mammalian GnRHRs more effectively than native GnRH-II. However, it exhibited lower activity for mammalian type-I GnRHR than GnRH-I itself. Trptorelix-1, a GnRH-II antagonist, inhibited GnRH- induced IP production in cells expressing non- mammalian GnRHRs more effectively than Cetrorelix, a GnRH-I antagonist. Trptorelix-1, however, had lower potency for mammalian type-I GnRHR than Cetrorelix. Ligand-receptor binding assays revealed that [D-Ala 6 ]GnRH-II and Trptorelix-1 have higher affinities for non-mammalian GnRHRs but lower af- finities for mammalian type-I GnRHR than GnRH-II and Cetrorelix, respectively. Moreover, [D-Ala 6 ]GnRH- II and Trptorelix-1 had a higher affinity for gmGnRHR-2 than GnRH-II and Cetrorelix, respec- tively. These results indicate that [D-Ala 6 ]GnRH-II and Trptorelix-1 are highly effective agonist and antagonist, respectively, for non-mammalian and type- II mammalian GnRHRs