Gpr68,也称为OGR1,是一种酸感应G蛋白偶联受体(GPCR)。Gpr68主要表达在多种细胞类型中,包括神经元、软骨细胞、肿瘤相关成纤维细胞等。Gpr68在感知和响应细胞外酸性环境方面发挥着重要作用,参与调节多种生物学过程,包括炎症、氧化应激、细胞凋亡、肿瘤发生和骨关节炎的进展。
在肿瘤发生方面,Gpr68在多种癌症组织中表达上调,包括胶质母细胞瘤、结直肠癌、头颈癌和胰腺癌。研究发现,Gpr68的激活可以促进肿瘤细胞的生长、侵袭和转移。例如,在胶质母细胞瘤中,Gpr68的激活可以抑制ATF4的表达,从而抑制细胞凋亡,促进肿瘤细胞的生存。此外,Gpr68还可以与肿瘤相关成纤维细胞相互作用,通过低pH环境增强IL-6的表达,进而促进肿瘤细胞的增殖。这些研究表明,Gpr68可能成为治疗多种癌症的潜在靶点[1][2][3][4][5][6][7][8]。
在骨关节炎的进展中,Gpr68的表达与软骨退化和疾病严重程度呈正相关。研究发现,Gpr68在软骨细胞中表达上调,并在IL-1β刺激下进一步增加。Gpr68的激活可以抑制基质金属蛋白酶(MMPs)的表达,从而抑制软骨降解和骨关节炎的进展。这表明,Gpr68可能成为治疗骨关节炎的潜在靶点[7]。
此外,Gpr68在神经系统中也发挥着重要作用。研究发现,Gpr68的敲除可以导致海马体长时程增强(LTP)受损和被动回避行为障碍。这表明,Gpr68参与调节神经突触可塑性和学习记忆过程[8]。
综上所述,Gpr68是一种重要的酸感应GPCR,参与调节多种生物学过程,包括炎症、氧化应激、细胞凋亡、肿瘤发生和骨关节炎的进展。Gpr68的表达和功能与多种疾病的发生和发展密切相关,可能成为治疗这些疾病的潜在靶点。
参考文献:
1. Williams, Charles H, Neitzel, Leif R, Cornell, Jessica, Bar, Eli E, Hong, Charles C. 2024. GPR68-ATF4 signaling is a novel prosurvival pathway in glioblastoma activated by acidic extracellular microenvironment. In Experimental hematology & oncology, 13, 13. doi:10.1186/s40164-023-00468-1. https://pubmed.ncbi.nlm.nih.gov/38291540/
2. Perren, Leonie, Busch, Moana, Schuler, Cordelia, Hausmann, Martin, Rogler, Gerhard. 2023. OGR1 (GPR68) and TDAG8 (GPR65) Have Antagonistic Effects in Models of Colonic Inflammation. In International journal of molecular sciences, 24, . doi:10.3390/ijms241914855. https://pubmed.ncbi.nlm.nih.gov/37834303/
3. Li, Xianglong, Xia, Kaiguo, Zhong, Chuanhong, Chen, Ligang, You, Jian. 2024. Neuroprotective effects of GPR68 against cerebral ischemia-reperfusion injury via the NF-κB/Hif-1α pathway. In Brain research bulletin, 216, 111050. doi:10.1016/j.brainresbull.2024.111050. https://pubmed.ncbi.nlm.nih.gov/39147243/
4. Neitzel, Leif R, Fuller, Daniela T, Williams, Charles H, Hong, Charles C. 2024. Inhibition of GPR68 kills glioblastoma in zebrafish xenograft models. In BMC research notes, 17, 235. doi:10.1186/s13104-024-06900-x. https://pubmed.ncbi.nlm.nih.gov/39180089/
5. Shore, David, Griggs, Nosakhere, Graffeo, Vincent, Xu, Yan, McAleer, Jeremy P. 2023. GPR68 limits the severity of chemical-induced oral epithelial dysplasia. In Scientific reports, 13, 353. doi:10.1038/s41598-023-27546-y. https://pubmed.ncbi.nlm.nih.gov/36611126/
6. Horiguchi, Kotaro, Higuchi, Masashi, Yoshida, Saishu, Kato, Takako, Kato, Yukio. 2014. Proton receptor GPR68 expression in dendritic-cell-like S100β-positive cells of rat anterior pituitary gland: GPR68 induces interleukin-6 gene expression in extracellular acidification. In Cell and tissue research, 358, 515-25. doi:10.1007/s00441-014-1958-x. https://pubmed.ncbi.nlm.nih.gov/25129106/
7. Khan, Nazir M, Diaz-Hernandez, Martha E, Martin, William N, Chihab, Samir, Drissi, Hicham. 2023. pH-sensing G protein-coupled orphan receptor GPR68 is expressed in human cartilage and correlates with degradation of extracellular matrix during OA progression. In PeerJ, 11, e16553. doi:10.7717/peerj.16553. https://pubmed.ncbi.nlm.nih.gov/38077417/
8. Xu, Yuanyuan, Lin, Mike T, Zha, Xiang-Ming. 2020. GPR68 deletion impairs hippocampal long-term potentiation and passive avoidance behavior. In Molecular brain, 13, 132. doi:10.1186/s13041-020-00672-8. https://pubmed.ncbi.nlm.nih.gov/32993733/