Neurodegenerative diseases, particularly Alzheimer’s disease and other dementias as well as Parkinson’s disease, are emerging as profoundly significant challenges and burdens to global health, a trend highlighted by the most recent Global Burden of Disease (GBD) 2021 studies. This growing impact is closely linked to the demographic shift toward an aging population and the potential long-term repercussions of the COVID-19 pandemic, both of which have intensified the prevalence and severity of these conditions. In this review, we explore several critical aspects of this complex issue, including the increasing global burden of neurodegenerative diseases, unmet medical and social needs within current care systems, the unique and amplified challenges posed by the COVID-19 pandemic, and potential strategies for enhancing healthcare policy and practice. We underscore the urgent need for cohesive, multidisciplinary approaches across medical, research, and policy domains to effectively address the increasing burden of neurodegenerative diseases, thereby improving the quality of life for patients and their caregivers.
Astrocyte and microglia activation are well-known features of temporal lobe epilepsy that may contribute to epileptogenesis. However, the mechanisms underlying glia activation are not well understood. Long non-coding RNA (lncRNA) H19 has diverse functions depending on physiological or pathological state, and its role in epilepsy is unknown. We previously demonstrated that H19 was significantly upregulated in the latent period of epilepsy and may be associated with cell proliferation and immune and inflammatory responses. We therefore speculated that H19 is involved in the hippocampal glial cell activation during epileptogenesis. H19 was overexpressed or knocked down using an adeno-associated viral vector delivery system. A rat status epilepticus model was induced by intra-amygdala kainic acid injection. Astrocyte and microglia activation were assessed by immunofluorescence and western blot analyses. Expression of proinflammatory cytokines and components of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways were evaluated with western blotting. H19 overexpression induced the activation of astrocytes and microglia and the release of proinflammatory cytokines (interleukin-1β and interleukin-6 and tumor necrosis factor-α) in the hippocampus, whereas H19 knockdown inhibited status epilepticus-induced glial cell activation. Moreover, H19 activated JAK/STAT signaling by promoting the expression of Stat3 and c-Myc, which is thought to be involved in astrocyte activation. LncRNA H19 contributes to hippocampal glial cell activation via modulation of the JAK/STAT pathway and could be a therapeutic tool to prevent the development of epilepsy.
Impaired activation and regulation of the extinction of inflammatory cells and molecules in injured neuronal tissues are key factors in the development of epilepsy. SerpinA3N is mainly associated with the acute phase response and inflammatory response. In our current study, transcriptomics analysis, proteomics analysis, and Western blotting showed that the expression level of Serpin clade A member 3N (SerpinA3N) is significantly increased in the hippocampus of mice with kainic acid (KA)-induced temporal lobe epilepsy, and this molecule is mainly expressed in astrocytes. Notably, in vivo studies using gain- and loss-of-function approaches revealed that SerpinA3N in astrocytes promoted the release of proinflammatory factors and aggravated seizures. Mechanistically, RNA sequencing and Western blotting showed that SerpinA3N promoted KA-induced neuroinflammation by activating the NF-κB signaling pathway. In addition, co-immunoprecipitation revealed that SerpinA3N interacts with ryanodine receptor type 2 (RYR2) and promotes RYR2 phosphorylation. Overall, our study reveals a novel SerpinA3N-mediated mechanism in seizure-induced neuroinflammation and provides a new target for developing neuroinflammation-based strategies to reduce seizure-induced brain injury.
Background: Increasing evidence suggests an association between pro-inflammatory diets and cognitive function. However, only a few studies based on small sample sizes have explored the association between pro-inflammatory diets and dementia using the dietary inflammatory index (DII). Additionally, the relationship between DII and different subtypes of dementia, such as Alzheimer's dementia and vascular dementia, remains largely unexplored. Given the changes in brain structure already observed in patients with dementia, we also investigated the association between DII and magnetic resonance imaging (MRI) measures of brain structure to provide some hints to elucidate the potential mechanisms between pro-inflammatory diet and cognitive decline. Methods: A total of 166,377 UK Biobank participants without dementia at baseline were analyzed. DII calculations were based on the information collected by the 24-h recall questionnaire. Brain structural anatomy and tissue-specific volumes were measured using brain MRI. Cox proportional hazards models, competing risk models, and restricted cubic spline were applied to assess the longitudinal associations. The generalized linear model was used to assess the association between DII and MRI measurements. Results: During a median follow-up time of 9.46 years, a total of 1372 participants developed dementia. The incidence of all-cause dementia increased by 4.6% for each additional unit of DII [hazard ratio (HR): 1.046]. Besides, DII displayed a “J-shaped” non-linear association with Alzheimer’s dementia (Pnonlinear = 0.003). When DII was above 1.30, an increase in DII was significantly associated with an increased risk of Alzheimer’s dementia (HR: 1.391, 95%CI: 1.085–1.784, P = 0.009). For brain MRI, the total volume of white matter hyperintensities increased with an increase in DII, whereas the volume of gray matter in the hippocampus decreased. Conclusions: In this cohort study, higher DII was associated with a higher risk of all-cause dementia and Alzheimer’s dementia. However, our findings suggested that the association with DII and vascular and frontotemporal dementia was not significant.
Temporal lobe epilepsy (TLE) is one of the most common types of intractable epilepsy, characterized by hippocampal neuron damage and hippocampal sclerosis. Long noncoding RNAs (lncRNAs) have been increasingly recognized as posttranscriptional regulators. However, their expression levels and functions in TLE remain largely unknown. In the present study, TLE rat model is used to explore the expression profiles of lncRNAs in the hippocampus of epileptic rats using microarray analysis. Our results demonstrate that H19 is the most pronouncedly differentiated lncRNA, significantly upregulated in the latent period of TLE. Moreover, the in vivo studies using gain- and loss-of-function approaches reveal that the overexpression of H19 aggravates SE-induced neuron apoptosis in the hippocampus, while inhibition of H19 protects the rats from SE-induced cellular injury. Finally, we show that H19 might function as a competing endogenous RNA to sponge microRNA let-7b in the regulation of cellular apoptosis. Overall, our study reveals a novel lncRNA H19-mediated mechanism in seizure-induced neural damage and provides a new target in developing lncRNA-based strategies to reduce seizure-induced brain injury.
8 December 2019 in CNS Neuroscience & Therapeutics
Background: Parkinson's disease (PD) is a common movement disorder for which diagnosis mainly depends on the medical history and clinical symptoms. Exosomes are now considered an additional mechanism for intercellular communication, allowing cells to exchange proteins, lipids, and genetic material. Long noncoding (lnc) RNA in exosomes plays a critical role in many diseases, including neurodegenerative disease.Aim: To study expression differences for lncRNAs in peripheral blood exosomes of PD patients compared with healthy individuals and to look for lncRNAs that might be related to the pathogenesis of PD.Materials and Methods: We recruited PD patients along with age‐ and sex‐matched healthy individuals as healthy controls and evaluated levels of lncRNAs extracted from exosomes in plasma samples via next‐generation sequencing and real‐time quantitative PCR. Correlation analysis was conducted for the clinical characteristics of PD patients and the expression of selected lncRNAs.Results: We found 15 upregulated and 24 downregulated exosomal lncRNAs in the PD group. According to bioinformatics analyses, we chose lnc‐MKRN2‐42:1 for further study. Interestingly, lnc‐MKRN2‐42:1 was positively correlated with the MDS‐UPDRS III score for PD patients.Conclusion: Our study suggested that lnc‐MKRN2‐42:1 may be involved in the occurrence and development of PD.