Multiple Layers of CDK5R1 Regulation in Alzheimer's Disease Implicate Long Non-Coding RNAs

Depletion of LncRNA NEAT1 Rescues Mitochondrial Dysfunction Through NEDD4L-Dependent PINK1 Degradation in Animal Models of Alzheimer's Disease

Alzheimer’s disease (AD) is the most common neurodegenerative disorder and the main cause of dementia among the elderly worldwide. Unfortunately, the mechanism of AD remains unclear, and no effective therapies are available yet. An increasing amount of studies have demonstrated that long non-coding RNAs (LncRNAs) play a notable role in the pathogenesis of plenty of human diseases, and they have served as biomarkers and potential therapeutic targets. However, the function of LncRNAs in AD remains unclear. This study aimed to explore the potential role of LncRNA nuclear enriched abundant transcript 1 (NEAT1) in AD. We found that LncRNA NEAT1 was upregulated in the AD animal models. Furthermore, we demonstrated that NEAT1 could interact with NEDD4L and promote PTEN-induced putative kinase 1 (PINK1)’s ubiquitination and degradation and then impaired PINK1-dependent autophagy. Collectively, the lncRNA NEAT1 promotes the pathogenesis of AD and serves as a promising novel target for pharmacological intervention.

The MicroRNA Centrism in the Orchestration of Neuroinflammation in Neurodegenerative Diseases

MicroRNAs (miRNAs) are small non-coding RNAs with a unique ability to regulate the transcriptomic profile by binding to complementary regulatory RNA sequences. The ability of miRNAs to enhance (proinflammatory miRNAs) or restrict (anti-inflammatory miRNAs) inflammatory signalling within the central nervous system is an area of ongoing research, particularly in the context of disorders that feature neuroinflammation, including neurodegenerative diseases (NDDs). Furthermore, the discovery of competing endogenous RNAs (ceRNAs) has led to an increase in the complexity of miRNA-mediated gene regulation, with a paradigm shift from a unidirectional to a bidirectional regulation, where miRNA acts as both a regulator and is regulated by ceRNAs. Increasing evidence has revealed that ceRNAs, including long non-coding RNAs, circular RNAs, and pseudogenes, can act as miRNA sponges to regulate neuroinflammation in NDDs within complex cross-talk regulatory machinery, which is referred to as ceRNA network (ceRNET). In this review, we discuss the role of miRNAs in neuroinflammatory regulation and the manner in which cellular and vesicular ceRNETs could influence neuroinflammatory dynamics in complex multifactorial diseases, such as NDDs.

Identification of age- and gender-associated long noncoding RNAs in the human brain with Alzheimer's disease

Alzheimer's disease (AD) is an age- and gender-associated brain disorder. Long noncoding RNAs (lncRNAs) have emerged as key regulators of brain development, homeostasis, and pathologies. Here, we used gene array data sets and bioinformatics analysis to identify differentially expressed age- and gender-associated lncRNAs in human AD brains. We found that the expressions of 16 age-associated and 13 gender-associated lncRNAs were dysregulated in AD brains. Notably, the expressions of age-associated lncRNAs-SNHG19 and LINC00672-were significantly correlated with Braak stage of AD, positively and negatively, respectively, whereas the expressions of gender-associated lncRNAs-RNF144A-AS1, LY86-AS1, and LINC00639-were negatively correlated with Braak stage of AD. Functional analysis suggests that the pathways involved in neurodegenerative diseases, synaptic vesicle cycle, and endocytosis were overly represented within age- and gender-associated lncRNA-correlating genes. The identification of age- and gender-associated lncRNAs and their differential expressions in the human AD brain provide potential targets for further experimental validation and mechanistic investigation, which could, in turn, pave the way for developing age- and gender-specific prevention and adjunctive therapeutic options for patients with AD.

Long Noncoding RNA NEAT1 Aggravates Aβ-Induced Neuronal Damage by Targeting miR-107 in Alzheimer's Disease

PURPOSE

Alzheimer's disease (AD) is the most common neurodegenerative disease, with a rising prevalence worldwide. Long noncoding RNAs (lncRNAs) have been found to play important roles in the development and treatment of AD. However, the exact role of lncRNA nuclear enriched abundant transcript 1 (NEAT1) in neuronal damage in AD is largely unknown.

MATERIALS AND METHODS

The AD model was established in SH-SY5Y and SK-N-SH cells via treatment with amyloid β1-42 (Aβ). The expression of NEAT1 and microRNA-107 (miR-107) was measured by quantitative real-time polymerase chain reaction. Cell viability and apoptosis were detected by MTT assay, immunocytochemistry, and flow cytometry. The expression of phosphorylated tau protein (p-Tau) was measured by Western blot. The interaction between NEAT1 and miR-107 was explored by bioinformatics analysis, luciferase activity, and RNA immunoprecipitation assays.

RESULTS

NEAT1 expression was enhanced in Aβ-treated SH-SY5Y and SK-N-SH cells, and its knockdown attenuated Aβ-induced inhibition of viability and promotion of apoptosis and p-Tau levels. NEAT1 was indicated as a decoy of miR-107. miR-107 abundance was reduced in Aβ-treated cells, and its overexpression reversed Aβ-induced injury. Moreover, interference of miR-107 abated silencing of NEAT1-mediated inhibition of neuronal damage in Aβ-treated SH-SY5Y and SK-N-SH cells.

CONCLUSION

LncRNA NEAT1 aggravated Aβ-induced neuronal damage by sponging miR-107, indicating a novel avenue for treatment of AD.

The long-non-coding RNA NEAT1 is a novel target for Alzheimer's disease progression via miR-124/BACE1 axis

OBJECTIVES

Long-non-coding RNAs (lncRNAs) have been involved in central nervous system recently. A number of studies have reported that lncRNA NEAT1 exerts critical roles in neurodegenerative disorder. Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) has been reported to exert function in the accumulation of amyloid-β (Aβ). Moreover, BACE1 acts as a target of miR-124 in the progression of AD. So far, the biological role and underlying mechanisms of NEAT1 and miR-124 in AD remains elusive.

METHODS

The relative NEAT1 and miR-124 expression was examined by qRT-PCR in the tissues and cells line of AD. Cell apoptosis was examined by FACS. Luciferase reporter assay was performed to verify that miR-124 is a direct target of NEAT1, and BACE1 is a downstream target of miR-124. qRT-PCR and western blot analysis were also performed to determinate the BACE1 and the phosphorylation of tau protein.

RESULTS

NEAT1 was notably up-regulated and miR-124 was remarkably down-regulated in AD mouse model. Knockdown of NEAT1 or overexpression of miR-124 showed the protective effects on cellular AD model induced by Aβ. Moreover, miR-124 expression could be up- and down-regulated by suppression or overexpression of NEAT1, respectively. In addition, the expression of BACE1 was the potential functional target of miR-124. These findings suggested that NEAT1 might play a vital role in the development of AD by regulating miR-124/BACE1 axis.

DISCUSSION

The present study showed that NEAT1 worked as a regulating factor to promote the development of AD via modulating miR-124/BACE1 axis, which might be considered as a novel target in AD treatment.

Retracted Article: Long noncoding RNA HOTAIR promotes cell apoptosis by sponging miR-221 in Parkinson's disease

Parkinson's disease (PD) is a common neurological disorder that is detrimental to the health of older people worldwide. Long noncoding RNAs (lncRNAs) have been reported to play essential roles in the pathogenesis and therapeutics of PD. LncRNA homeobox transcript antisense intergenic RNA (HOTAIR) is expressed in PD samples; however, the exact roles of HOTAIR and its mechanism remain largely unclear. Herein, the neurotoxins 1-methyl-4-phenylpyridine (MPP⁺) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were used to establish PD models in vitro and in vivo. The expressions of HOTAIR and microRNA-221 (miR-221) were measured by the quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis were detected by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and western blot or flow cytometry, respectively. The interaction between HOTAIR and miR-221 was explored by luciferase activity and RNA immunoprecipitation (RIP). The tyrosine hydroxylase (TH)-positive cells in MPTP-treated-mouse midbrains were analyzed by immunohistochemistry. The HOTAIR expression was up-regulated and that of miR-221 was down-regulated in the serum of PD patients and MPP⁺-treated SH-SY5Y cells. Overexpression of HOTAIR inhibited cell viability and promoted apoptosis in MPP⁺-treated SH-SY5Y cells. However, the down-regulation of HOTAIR showed an opposite effect. Moreover, miR-221 was validated to be bound to HOTAIR, and its addition reversed the regulatory effect of HOTAIR on cell viability and apoptosis in MPP⁺-treated SH-SY5Y cells. Moreover, the knockdown of HOTAIR attenuated the degree of PD and cell apoptosis by regulating miR-221 in MPTP-treated mice. In conclusion, HOTAIR contributed to cell apoptosis by sponging miR-221 in PD. This study elucidates a new mechanism for understanding the pathogenesis of PD and provides a promising target for the treatment of PD.

Parkinson's disease (PD) is a common neurological disorder that is detrimental to the health of older people worldwide.

NEAT1 and paraspeckles in neurodegenerative diseases: A missing lnc found?

Neurodegenerative diseases are among the most common causes of disability worldwide. Although neurodegenerative diseases are heterogeneous in both their clinical features and the underlying physiology, they are all characterised by progressive loss of specific neuronal populations. Recent experimental evidence suggests that long non-coding RNAs (lncRNAs) play important roles in the CNS in health and disease. Nuclear Paraspeckle Assembly Transcript 1 (NEAT1) is an abundant, ubiquitously expressed lncRNA, which forms a scaffold for a specific RNA granule in the nucleus, or nuclear body, the paraspeckle. Paraspeckles act as molecular hubs for cellular processes commonly affected by neurodegeneration. Transcriptomic analyses of the diseased human tissue have revealed altered NEAT1 levels in the CNS in major neurodegenerative disorders as well as in some disease models. Although it is clear that changes in NEAT1 expression (and in some cases, paraspeckle assembly) accompany neuronal damage, our understanding of NEAT1 contribution to the disease pathogenesis is still rudimentary. In this review, we have summarised the available knowledge on NEAT1 involvement in the molecular processes linked to neurodegeneration and on NEAT1 dysregulation in this type of disease, with a special focus on amyotrophic lateral sclerosis. The goal of this review is to attract the attention of researchers in the field of neurodegeneration to NEAT1 and paraspeckles.

Altered Levels of Long NcRNAs Meg3 and Neat1 in Cell And Animal Models Of Huntington's Disease

Altered expression levels of protein-coding genes and microRNAs have been implicated in the pathogenesis of Huntington's disease (HD). The involvement of other ncRNAs, especially long ncRNAs (lncRNA), is being realized recently and the related knowledge is still rudimentary. Using small RNA sequencing and PCR arrays we observed perturbations in the levels of 12 ncRNAs in HD mouse brain, eight of which had human homologs. Of these, Meg3, Neat1, and Xist showed a consistent and significant increase in HD cell and animal models. Transient knock-down of Meg3 and Neat1 in cell models of HD led to a significant decrease of aggregates formed by mutant huntingtin and downregulation of the endogenous Tp53 expression. Understanding Meg3 and Neat1 functions in the context of HD pathogenesis is likely to open up new strategies to control the disease.