title: αν and β1 Integrins mediate Aβ-induced neurotoxicity in hippocampal neurons via the FAK signaling pathway.
abstract: αν and β1 integrins mediate Aβ-induced neurotoxicity in primary hippocampal neurons. We treated hippocampal neurons with 2.5 µg/mL 17E6 and 5 µg/mL ab58524, which are specific αν and β1 integrin antagonists, respectively, for 42 h prior to 10 µM Aβ treatment. Next, we employed small interfering RNA (siRNA) to silence focal adhesion kinase (FAK), a downstream target gene of integrins. The siRNAs were designed with a target sequence, an MOI of 10 and the addition of 5 µg/mL polybrene. Under these conditions, the neurons were transfected and the apoptosis of different cell types was detected. Moreover, we used real-time PCR and Western blotting analyses to detect the expression of FAK and ρFAK genes in different cell types and investigated the underlying mechanism and signal pathway by which αν and β1 integrins mediate Aβ-induced neurotoxicity in hippocampal neurons. An MTT assay showed that both 17E6 and ab58524 significantly increased cell viability compared with the Aβ-treated neurons (P<0.01 and P<0.05, respectively). However, this protective effect was markedly attenuated after transfection with silencing FAK (siFAK). Moreover, TUNEL immunostaining and flow cytometry indicated that both 17E6 and ab58524 significantly protected hippocampal neurons against apoptosis induced by Aβ (P<0.05) compared with the Aβ-treated cells. However, this protective effect was reversed with siFAK treatment. Both the gene and protein expression of FAK increased after Aβ treatment. Interestingly, as the gene and protein levels of FAK decreased, the ρFAK protein expression markedly increased. Furthermore, both the gene and protein expression of FAK and ρFAK were significantly diminished. Thus, we concluded that both αν and β1 integrins interfered with Aβ-induced neurotoxicity in hippocampal neurons and that this mechanism partially contributes to the activation of the Integrin-FAK signaling pathway.
authors.affiliation: Department of Neurology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei Province, China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Han
authors.forename: Jin-Ping
authors.initials: JP
authors.lastname: Zhang
authors.forename: Su-Qiong
authors.initials: SQ
authors.lastname: Ji
authors.forename: Qi-Ming
authors.initials: QM
authors.lastname: Liang
authors.forename: Hui-Cong
authors.initials: HC
authors.lastname: Kang
authors.forename: Rong-Hua
authors.initials: RH
authors.lastname: Tang
authors.forename: Sui-Qiang
authors.initials: SQ
authors.lastname: Zhu
authors.forename: Zheng
authors.initials: Z
authors.lastname: Xue
mesh_terms: D016229:Amyloid beta-Peptides / Q000633:toxicity*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D005434:Flow Cytometry; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D006624:Hippocampus / Q000473:pathology*; D020287:In Situ Nick-End Labeling; D039564:Integrin alphaV / Q000378:metabolism*; D019012:Integrin beta1 / Q000378:metabolism*; D016086:Lentivirus / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D018696:Neuroprotective Agents / Q000494:pharmacology; D009498:Neurotoxins / Q000633:toxicity*; D010766:Phosphorylation / Q000187:drug effects; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D014162:Transfection
chemical_list: D016229:Amyloid beta-Peptides; D039564:Integrin alphaV; D019012:Integrin beta1; D008869:Microtubule-Associated Proteins; D018696:Neuroprotective Agents; D009498:Neurotoxins; D034741:RNA, Small Interfering; D051416:Focal Adhesion Protein-Tyrosine Kinases