Regulatory role of LncRNA FMR1-AS1 in the pathogenesis of alzheimer's disease based on bioinformatics and in vitro experimental validation

Abstract

Alzheimer's disease (AD) is a major cause of dementia, characterized by β-amyloid (Aβ) plaque accumulation and Tau protein hyperphosphorylation. Although long non-coding RNAs (lncRNAs) have been implicated in neurodegenerative diseases, their roles in AD remain unclear. This study analyzed RNA sequencing data from the brain tissues of 17 AD patients and 19 healthy controls (GEO: GSE138260) to construct a gene co-expression network and identified eight lncRNAs strongly associated with AD. FMR1-AS1 was selected for functional validation. In an Aβ1-42-induced SH-SY5Y neuronal injury model, overexpression of FMR1-AS1 significantly increased cell viability ([Formula: see text]), inhibited apoptosis ([Formula: see text]), and reduced Tau hyperphosphorylation ([Formula: see text]). FMR1-AS1 also alleviated oxidative stress by lowering reactive oxygen species (ROS) levels ([Formula: see text]), enhanced superoxide dismutase (SOD) activity ([Formula: see text]), and decreased malondialdehyde (MDA) content ([Formula: see text]). Knockdown of FMR1-AS1 exacerbated neuronal damage. These results demonstrate that FMR1-AS1 exerts neuroprotective effects by regulating apoptosis, oxidative stress, and Tau pathology. The study highlights FMR1-AS1 as a potential therapeutic target for AD and may advance the understanding of lncRNA-mediated regulatory mechanisms in neurodegeneration.

Keywords: FMR1-AS1; Alzheimer’s disease; Aβ1–42; Bioinformatics; Neuronal cells; Oxidative stress; Tau phosphorylation.

Fig. 1

Overall analytical and experimental workflow of this study.

Fig. 2

(a) Changes in scale-free topology fit index () and mean connectivity under different soft-thresholding powers. The red line marks the threshold . (b) Heatmap showing correlations between gene modules and clinical traits; (c) GO (BP/CC/MF) and KEGG enrichment analysis of the MEblue module. The x-axis represents the number of enriched genes, and the y-axis indicates significantly enriched GO terms or KEGG pathways^,; (d) Adjacency heatmap of selected lncRNAs and co-expressed genes within the MEblue module. The heatmap displays pairwise adjacency values between the selected lncRNAs and genes in the MEblue module. Both the x- and y-axes represent gene names. The color intensity indicates network connectivity between gene pairs, with redder colors denoting stronger co-expression, suggesting tighter functional associations.

Fig. 3

(a) Time-dependent morphological changes in SH-SY5Y cells induced by A1–42 exposure; (b) Time-dependent changes in SH-SY5Y cell viability following A1–42 exposure. (c, d) Western blot analysis of total Tau and phosphorylated Tau protein levels in SH-SY5Y cells treated with A1–42. *p < 0.05, **p < 0.01, ***p < 0.001 vs. A1–42-treated group. Unprocessed full-length blots are provided in Supplementary Figs. S3 and S4.

Fig. 4

(a) qRT-PCR analysis of FMR1-AS1 expression levels in SH-SY5Y cells treated with A1-42 (10 M) for different time periods. *, **, *** vs. A1-42 treatment group; (b, c) qRT-PCR analysis of FMR1-AS1 expression in SH-SY5Y cells treated with A1-42 (10 M, 24 h) following transfection with oe-FMR1-AS1 or si-FMR1-AS1 plasmids. *** vs. empty vector control group; (d) MTT assay analysis of the effects of FMR1-AS1 overexpression and knockdown on SH-SY5Y cell viability. Data are presented as mean ± standard deviation (). *p < 0.05, **p < 0.01, ***p < 0.001 vs. the A1–42-treated group.

Fig. 5

(a, b) Flow cytometry was used to assess the effects of FMR1-AS1 overexpression and knockdown on apoptosis in SH-SY5Y cells treated with A1-42 (10 M, 24 h). *, **, *** vs. the A1-42-treated group.

Fig. 6

(a, b) Intracellular ROS levels were measured using the DCFH-DA fluorescent probe. (c, d) Oxidative stress markers in SH-SY5Y cells treated with A1-42 (10 M, 24 h) were assessed using SOD and MDA assay kits to evaluate the effect of FMR1-AS1. *, **, *** vs. A1-42 treatment group.