Plasma lncRNA profiling identified BC200 and NEAT1 lncRNAs as potential blood-based biomarkers for late-onset Alzheimer's disease

The roles of long non-coding RNAs in Alzheimer's disease diagnosis, treatment, and their involvement in Alzheimer's disease immune responses

Alzheimer's disease (AD) is the most frequent type of dementia, presenting a substantial danger to the health and well-being of the aged population. It has arisen as a significant public health problem with considerable socioeconomic repercussions. Unfortunately, no effective treatments or diagnostic tools are available for Alzheimer's disease. Despite substantial studies on the pathophysiology of Alzheimer's, the molecular pathways underpinning its development remain poorly understood. Long non-coding RNAs (lncRNAs) vary in size from 200 nucleotides to over 100 kilobytes and have been found to play critical roles in various vital biological processes that play critical in developing Alzheimer's disease. This review intends to examine the functions of long non-coding RNAs in diagnosing and treating Alzheimer's disease and their participation in immunological responses associated with AD.

LncRNA ENST00000440246.1 Promotes Alzheimer's Disease Progression by Targeting PP2A

Alzheimer's disease (AD) is an extremely prevalent neurodegenerative disease. Long noncoding RNAs (lncRNAs) play pivotal roles in the regulation of AD. However, the function of most lncRNAs in AD remains to be elucidated. In this study, the effects of lncRNA ENST00000440246.1 on the biological characteristics of AD were explored. Differentially expressed lncRNAs in AD were identified through bioinformatics analysis and peripheral blood from thirty AD patients was collected to verify the expression of these lncRNAs by quantitative real-time polymerase chain reaction (RT-qPCR). The correlations between lncRNAs and the Mini-Mental State Examination (MMSE) or the Montreal Cognitive Assessment (MoCA) were assessed by Pearson's correlation analysis. Immunofluorescence (IF), Cell Counting Kit-8 (CCK-8) and flow cytometry assays were conducted to evaluate the biological effect of ENST00000440246.1 and protein phosphatase 2 A (PP2A) in SK-N-SH cells. Gene expression at the protein and mRNA levels was analyzed by Western blotting and RT-qPCR. The interaction between PP2A and ENST00000440246.1 was confirmed by IntaRNA and RNA pulldown assays. ENST00000440246.1 was upregulated and significantly negatively correlated with the MMSE and MoCA scores and the overexpression of ENST00000440246.1 inhibited cell proliferation and facilitated apoptosis and Aβ expression in SK-N-SH cells. Mechanistically, ENST00000440246.1 targeted PP2A and regulated AD-related gene expression. The silencing of ENST00000440246.1 had the opposite effect. Furthermore, PP2A overexpression reversed the influence of ENST00000440246.1 overexpression in SK-N-SH cells. In conclusion, ENST00000440246.1 could promote AD progression by targeting PP2A, which indicates that ENST00000440246.1 has the potential to be a diagnostic target in AD.

E2F1 Mediates Traumatic Brain Injury and Regulates BDNF-AS to Promote the Progression of Alzheimer's Disease

Traumatic brain injury (TBI) is one of the important risk factors for the development of Alzheimer's disease (AD). However, the molecular mechanism by which TBI promotes the progression of AD is not elucidated. In this study, we showed that the abnormal production of E2F1 is a major factor in promoting the neuropathological and cognitive deterioration of AD post-TBI. We found that repeated mild TBI can aggravate the neuropathology of AD in APP/PS1 mice. At the same time, the co-expression of E2F1 and beta-site APP cleaving enzyme 1 (BACE1) was upregulated when the mouse hippocampus was dissected. BACE1 is recognized as a rate-limiting enzyme for the production of Aβ. Here, we speculate that E2F1 may play a role in promoting BACE1 expression in AD. Therefore, we collected peripheral blood from patients with AD. Interestingly, there is a positive correlation between E2F1 and brain-derived neurotrophic factor-antisense (BDNF-AS), whereas BDNF-AS in AD can promote the expression of BACE1 and exhibit a neurotoxic effect. We established a cell model and found a regulatory relationship between E2F1 and BDNF-AS. Therefore, based on our results, we concluded that E2F1 regulates BDNF-AS, promotes the expression of BACE1, and affects the progression of AD. Furthermore, E2F1 mediates the TBI-induced neurotoxicity of AD.

The Role of Non-coding RNAs in Alzheimer's Disease: Pathogenesis, Novel Biomarkers, and Potential Therapeutic Targets

Long non-coding RNAs (IncRNAs) are regulatory RNA transcripts that have recently been associated with the onset of many neurodegenerative illnesses, including Alzheimer's disease (AD). Several IncRNAs have been found to be associated with AD pathophysiology, each with a distinct mechanism. In this review, we focused on the role of IncRNAs in the pathogenesis of AD and their potential as novel biomarkers and therapeutic targets. Searching for relevant articles was done using the PubMed and Cochrane library databases. Studies had to be published in full text in English in order to be considered. Some IncRNAs were found to be upregulated, while others were downregulated. Dysregulation of IncRNAs expression may contribute to AD pathogenesis. Their effects manifest as the synthesis of beta-amyloid (Aβ) plaques increases, thereby altering neuronal plasticity, inducing inflammation, and promoting apoptosis. Despite the need for more investigations, IncRNAs could potentially increase the sensitivity of early detection of AD. Until now, there has been no effective treatment for AD. Hence, InRNAs are promising molecules and may serve as potential therapeutic targets. Although several dysregulated AD-associated lncRNAs have been discovered, the functional characterization of most lncRNAs is still lacking.

The siRNA-mediated knockdown of SNHG4 efficiently induced pro-apoptotic signaling and suppressed metastasis in SW1116 colorectal cancer cell line

BACKGROUND

Long non-coding RNAs are broadly dysregulated in disease conditions, especially cancer, and are associated with tumor initiation, invasion, and overall survival. This study aimed to elucidate the expression level of Small Nucleolar RNA Host Gene 4 (SNHG4) lncRNA in colorectal cancer (CRC) and its effect on cell cycle progression, invasion, and death.

METHODS AND RESULTS

We evaluated the expression level of SNHG4 in clinical samples, including CRC tissues, adenomatous colorectal polyps (ACP), and their marginals. SNHG4-silenced SW1116 cells were used to evaluate the cell viability, cycle arrest, invasion, and apoptosis using MTT assay, scratching, flow cytometry, and immunoblotting. We also predicted molecular networks related to the SNHG4 involvement in CRC development. Results showed that SNHG4 expresses in cancerous tissues significantly higher than in polyps and marginals. This overexpression discriminated CRC from marginals and ACP with a suitable prognostic potential. Silencing of SNHG4 arrested the cell cycle at S and G2 phases and promoted early apoptosis in SW1116. It affected the active form of MMP2 and prevented cell invasion. Sponging of miRNAs which promotes the choline metabolism is the probable mechanism of SNHG4 involvement in CRC.

CONCLUSIONS

In conclusion, SNHG4 promotes CRC by dysregulating apoptosis and cell migration, and shows significant prognostic potential for CRC.

Non-Coding RNA in Microglia Activation and Neuroinflammation in Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by complex pathophysiological features. Amyloid plaques resulting from extracellular amyloid deposition and neurofibrillary tangles formed by intracellular hyperphosphorylated tau accumulation serve as primary neuropathological criteria for AD diagnosis. The activation of microglia has been closely associated with these pathological manifestations. Non-coding RNA (ncRNA), a versatile molecule involved in various cellular functions such as genetic information storage and transport, as well as catalysis of biochemical reactions, plays a crucial role in microglial activation. This review aims to investigate the regulatory role of ncRNAs in protein expression by directly targeting genes, proteins, and interactions. Furthermore, it explores the ability of ncRNAs to modulate inflammatory pathways, influence the expression of inflammatory factors, and regulate microglia activation, all of which contribute to neuroinflammation and AD. However, there are still significant controversies surrounding microglial activation and polarization. The categorization into M1 and M2 phenotypes may oversimplify the intricate and multifaceted regulatory processes in microglial response to neuroinflammation. Limited research has been conducted on the role of ncRNAs in regulating microglial activation and inducing distinct polarization states in the context of neuroinflammation. Moreover, the regulatory mechanisms through which ncRNAs govern microglial function continue to be refined. The current understanding of ncRNA regulatory pathways involved in microglial activation remains incomplete and may be influenced by spatial, temporal, and tissue-specific factors. Therefore, further in-depth investigations are warranted. In conclusion, there are ongoing debates and uncertainties regarding the activation and polarization of microglial cells, particularly concerning the categorization into M1 and M2 phenotypes. The study of ncRNA regulation in microglial activation and polarization, as well as its mechanisms, is still in its early stages and requires further investigation. However, this review offers new insights and opportunities for therapeutic approaches in AD. The development of ncRNA-based drugs may hold promise as a new direction in AD treatment.

The lncRNA Neat1 is associated with astrocyte reactivity and memory deficits in a mouse model of Alzheimer's disease

Dysregulation of long non-coding RNAs (lncRNAs) have been associated with Alzheimer's disease (AD). However, the functional role of lncRNAs in AD remains unclear. Here, we report a crucial role for the lncRNA Neat1 in astrocyte dysfunction and memory deficits associated with AD. Transcriptomics analysis show abnormally high expression levels of NEAT1 in the brains of AD patients relative to aged-matched healthy controls, with the most significantly elevated levels in glial cells. In a human transgenic APP-J20 (J20) mouse model of AD, RNA-fluorescent in situ hybridization characterization of Neat1 expression in hippocampal astrocyte versus non-astrocyte cell populations revealed a significant increase in Neat1 expression in astrocytes of male, but not female, mice. This corresponded with increased seizure susceptibility in J20 male mice. Interestingly, Neat1 deficiency in the dCA1 in J20 male mice did not alter seizure threshold. Mechanistically, Neat1 deficiency in the dorsal area CA1 of the hippocampus (dCA1) J20 male mice significantly improved hippocampus-dependent memory. Neat1 deficiency also remarkably reduced astrocyte reactivity markers suggesting that Neat1 overexpression is associated with astrocyte dysfunction induced by hAPP/Aβ in the J20 mice. Together, these findings indicate that abnormal Neat1 overexpression may contribute to memory deficits in the J20 AD model not through altered neuronal activity, but through astrocyte dysfunction.

Insights into the radiotherapy-induced deferentially expressed RNAs in colorectal cancer management

Radiotherapy (RT) has been commonly applied to treat advanced local cancers. In radiation therapy, high doses of radiation are utilized to trigger cell death. Radiation often leads to DNA double-strand breakages (DSB), which causes the activation of downstream genes including those for non-coding RNAs (ncRNA) such as long non-coding and RNAsmicro RNAs. The consequence of RT significantly relies on the radiosensitivity of cancer cells, which is affected by multiple factors, including some proteins and cellular processes. Activation of these genes can cause cell cytotoxicity and indirectly damages the cells. Recent studies have shown that non-coding RNAs can play as radiosensitivity or radioinhibitory regulators in cancers by mechanisms such as cell cycle arrest or affecting the DNA damage repair systems. ncRNAs are also known to function as tumor suppressor genes or oncogenes in colorectal cancer and therefore are considered potential diagnostic biomarkers in disease detection. For example, the investigations have shown that miR-29a and miR-224 can be informative biomarkers for early detection or screening of CRC via a noninvasive method such as liquid biopsy. Here, we discuss ncRNAs involved in the radioresistance and radiosensitivity of CRC and highlight their predictive clinical value in response to RT. Accordingly, this review represents a principal guide in the context of three major types of ncRNAs with potential roles in the pathway of radiosensitivity and radioresistance, including miRNAs, lncRNAs, and circRNAs which can be considered a precious archivement in organizing additional studies and broadening views in this area. Our findings can also assist radiotherapists in predicting CRC patients' response and, therefore, prognosis to radiation therapy, although, to achieve our goals in the clinic, we certainly need further studies.

Bibliometric analysis of research on Alzheimer’s disease and non-coding RNAs: Opportunities and challenges

Background

Non-coding RNAs (ncRNA) are a kind of RNA that does not encode protein, which play an important role in Alzheimer’s disease (AD). However, there is a lack of bibliometric analysis and visualization analysis of the research related to AD and ncRNAs.

Materials and methods

Literature related to AD and ncRNAs in the last decade were searched through the Web of Science Core Collection (WOSCC). The relevant information from all the searched articles was collected. The bibliometric visualization website, CiteSpace, and VOSviewer were used for visualization analysis of countries/regions, institutions, authors, and keywords.

Results

In total, 1,613 kinds of literature were published in the field. Literature in this field were published in 494 journals. The Journal of Alzheimer’s Disease was the most popular journal. China, Louisiana State University System, and Lukiw WJ were the countries/regions, institutions, and authors with the highest scientific productivity, respectively. The research hotspots in this field focused on the role and mechanism of ncRNAs, especially microRNAs, in AD. The level of research was mainly based on basic research, focusing on animal and cellular levels, and related to proteomics. “Circular RNAs,” “regulation of neuroinflammation,” and “tau protein” were the future research directions.

Conclusion

Taken together, the field of AD and ncRNAs is developing well. The research hotspots and frontiers in this field can provide a reference for researchers to choose their research direction.

Potential of hsa-miR200a-3p and hsa-miR502-3p as blood-based biomarker for Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is one of the most important known dementia which affects thousands of people every year. Many factors are involved in this process, such as aberrant expression of miRNAs.

METHODS AND RESULTS

Firstly, we analyzed two microarray datasets related to AD (GSE48552, GSE129053) to identify the differentially expressed miRNAs, and two miRNAs were selected for further validation. Dataset analysis showed that the expression of hsa-miR200a-3p and hsa-miR502-3p were up-regulated in AD. These findings were validated in plasma samples by qRT-PCR. ROC curve analysis showed that plasma levels of both miRNAs might discriminate the AD and healthy controls. In addition, in silico analysis revealed that the upregulation of these miRNAs could promote AD progression via affecting the expression of target molecules mainly ATF6 and dynactin.

CONCLUSION

Totally, hsa-miR200a-3p and hsa-miR502-3p are upregulated in AD and their plasma levels can discriminate AD and healthy people, highlighting their potential as blood-based biomarker for AD.

Insights into the mechanisms of non-coding RNAs' implication in the pathogenesis of Alzheimer's disease

Non-coding RNAs including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are implicated in the regulation of gene expression at transcriptional, posttranscriptional, and epigenetic levels. Several studies in cell lines, animal models, and humans, have revealed that non-coding RNAs play crucial roles in the pathogenesis of Alzheimer's disease (AD). Detailed knowledge on their mechanism of implication in the AD pathogenesis can help to develop novel therapeutic and disease management strategies. The two main pathological hallmarks of AD are amyloid plaques resulting from the β-amyloid accumulation, and neurofibrillary tangles (NFT) due to the phosphorylated tau accumulation. Several lncRNAs and miRNAs play crucial roles in both these hallmarks of the AD pathogenesis and other AD-related pathological procedures such as neuronal and synaptic plasticity, neuroinflammation, neuronal differentiation and neuronal apoptosis. In this review, we outlined the non-coding RNAs and further discussed how they are implicated in these AD-related pathological procedures.