Project description:Organotypic slice cultures from prostate cancer patients were generated and treated with or without 17b-estradiol or DHT to study estrogen and androgen signalling pathways.
Project description:Gene expression changes induced by alpha-secretase cleaved amyloid precursor protein (sAPPalpha) in organotypic hippocampal slice cultures of male, postnatal day 15 mice (C57B6/SJL). Hippocampal slice cultures were treated with phosphate buffered saline (GSM26700, GSM26701, GSM26702) or 1 nM sAPPalpha (GSM26703, GSM26704, GSM26705) for 24 h. Each sample consists of total RNA isolated from 8-12 slices from 4 mice. Data were analyzed with MAS 5.0 and scaled to 2500. sAPPalpha induces the amyloid sequestration protein transthyretin, insulin-like growth factor 2, insulin-like growth factor binding protein 2, and other genes involved in protective pathways such as apoptosis inhibition, detoxification, and retinol transport. Keywords = Alzheimer's disease Keywords = neuroprotection Keywords = sAPPalpha
Project description:The numerous neurological syndromes associated with COVID-19 implicate an effect of viral pathogenesis on neuronal function, yet reports of direct SARS-CoV-2 infection in the brain are conflicting. We used a well-established organotypic brain slice culture to determine the permissivity of hamster brain tissues to SARS-CoV-2 infection. We found levels of live virus waned after inoculation and observed no evidence of cell-to-cell spread, indicating that SARS-CoV-2 infection was non-productive. Nonetheless, we identified a small number of infected cells with glial phenotypes; yet no evidence of viral infection or replication was observed in neurons. Our data corroborates several clinical studies that have assessed patients with COVID-19 and their association with neurological involvement.
Project description:We previously encountered regulatory processes where dihydrotestosterone (DHT) exerted its inhibitory effect on parathyroid hormone-related protein (PTHrP) gene repression through the estrogen receptor (ER)α, but not the androgen receptor (AR) in breast cancer MCF-7 cells. Here, we investigated whether such an aberrant ligand-nuclear receptor (NR) interaction is present in prostate cancer LNCaP cells. First, we confirmed that LNCaP cells expressed a functional AR and at negligible levels of ERα, and progesterone receptors. Both suppression of PTHrP and activation of the PSA genes were observed after treatment of E2, DHT and R5020. Consistent with the previous notion that the AR in LNCaP cells lost the ligand specificity due to a mutation AR (Thr-Ala877), our study using siRNA targeting each NR revealed that the AR, but not the other NRs, monopolized the role as the mediator of shared hormone-dependent regulation. These results were invariably associated with nuclear translocation of this mutant AR. Microarray of the genes regulated by either DHT, E2 or R5020 downstream of the AR (Thr-Ala877) revealed that more than half genes overlapped in LNCaP cells. Noticeably, AR (wild-type, wt) and AR (Thr-Ala877) were equally responsible for the E2-AR interactions. Fluorescent microscopic experiments demonstrated that both EGFP-AR (wt) and EGFP-AR (Thr-Ala877) were exclusively localized within the nucleus after E2 or DHT treatment. Further, a promoter assay revealed that breast cancer MCF-7 and Rv22 cells also exhibited such an aberrant E2-AR (wt) signaling. We postulate entangled interactions between the AR (wt) and E2 in a certain hormone-sensitive cancer cells.
Project description:We previously encountered regulatory processes where dihydrotestosterone (DHT) exerted its inhibitory effect on parathyroid hormone-related protein (PTHrP) gene repression through the estrogen receptor (ER)M-NM-1, but not the androgen receptor (AR) in breast cancer MCF-7 cells. Here, we investigated whether such an aberrant ligand-nuclear receptor (NR) interaction is present in prostate cancer LNCaP cells. First, we confirmed that LNCaP cells expressed a functional AR and at negligible levels of ERM-NM-1, and progesterone receptors. Both suppression of PTHrP and activation of the PSA genes were observed after treatment of E2, DHT and R5020. Consistent with the previous notion that the AR in LNCaP cells lost the ligand specificity due to a mutation AR (Thr-Ala877), our study using siRNA targeting each NR revealed that the AR, but not the other NRs, monopolized the role as the mediator of shared hormone-dependent regulation. These results were invariably associated with nuclear translocation of this mutant AR. Microarray of the genes regulated by either DHT, E2 or R5020 downstream of the AR (Thr-Ala877) revealed that more than half genes overlapped in LNCaP cells. Noticeably, AR (wild-type, wt) and AR (Thr-Ala877) were equally responsible for the E2-AR interactions. Fluorescent microscopic experiments demonstrated that both EGFP-AR (wt) and EGFP-AR (Thr-Ala877) were exclusively localized within the nucleus after E2 or DHT treatment. Further, a promoter assay revealed that breast cancer MCF-7 and Rv22 cells also exhibited such an aberrant E2-AR (wt) signaling. We postulate entangled interactions between the AR (wt) and E2 in a certain hormone-sensitive cancer cells. Total RNAs from the LNCaP cells transfected with control siRNA (siCT) or siRNA for AR (siAR) transfected LNCaP cells before 24 hr followed by exposed to 10-7M of DHT, E2 or R5020 exposure for another 24 h, respectively, were used.
Project description:Gene expression changes induced by alpha-secretase cleaved amyloid precursor protein (sAPPalpha) in organotypic hippocampal slice cultures of male, postnatal day 15 mice (C57B6/SJL). Hippocampal slice cultures were treated with phosphate buffered saline (GSM26700, GSM26701, GSM26702) or 1 nM sAPPalpha (GSM26703, GSM26704, GSM26705) for 24 h. Each sample consists of total RNA isolated from 8-12 slices from 4 mice. Data were analyzed with MAS 5.0 and scaled to 2500. sAPPalpha induces the amyloid sequestration protein transthyretin, insulin-like growth factor 2, insulin-like growth factor binding protein 2, and other genes involved in protective pathways such as apoptosis inhibition, detoxification, and retinol transport. See Stein, TD, Anders, NJ, DeCarli, C, Chan, SL, Mattson, MP, and Johnson JA. Neutralization of transthyretin reverses the neuroprotective effects of secreted APP in APPSw mice resulting in tau phosphorylation and loss of hippocampal neurons: support for the amyloid hypothesis. J Neurosci. in press.
Project description:The neurite outgrowth inhibitory myelin protein Nogo-A has been well studied in the context of central nervous system (CNS) injury and disease. We studied the effects of the application of neutralizing anti-Nogo-A antibodies (11C7 and 7B12) in intact CNS tissue in vitro using rat organotypic hippocampal slice cultures. This study had the purpose of elucidating the role of Nogo-A in the adult intact CNS and determining the consequences of its neutralization through antibody application. In vitro cultures treated with anti-Nogo-A antibody showed an elicited growth response. The results also gave indications that hippocampal circuitry might be altered due to the regulation at the synaptic and neurotransmission level.