The Top-Cited Original Articles on the Role of Microglia in Neurodegenerative Diseases: A Bibliometric and Visualized Study

Novel anti-inflammatory compounds that alleviate experimental autoimmune encephalomyelitis

BACKGROUND

Multiple sclerosis (MS) is an autoimmune disease primarily characterized by inflammatory demyelination. Despite significant research efforts, effective therapies for MS remain limited. Drug screening offers a promising approach to rapidly identifying potential therapeutic compounds.

PURPOSE

This study aimed to screen compounds that can exert anti-inflammatory effects and alleviate experimental autoimmune encephalomyelitis (EAE), an animal model of MS.

STUDY DESIGN

A fundamental research in vitro and in vivo. A high-throughput screen was performed to screen drugs that can mitigate EAE and the molecular mechanism was explored.

METHODS

Based on our previous research highlighting the crucial role of AXL, a receptor tyrosine kinase, in microglial function, we constructed an AXL-GFP reporter gene in BV2 microglia cells. A high-throughput screen of an FDA-approved compound library was performed to identify potential AXL-targeting compounds. The effects of candidate compounds on cellular morphology, cell cycle, apoptosis, mitochondrial function, inflammatory cytokine production, polarization, and phagocytic activity of BV2 cells were assessed. To investigate the in vivo effects of AXL modulation, EAE mice were generated. AXL was either upregulated using recombinant Gas6 protein or knocked out using CRISPR/Cas9. The impact of AXL modulation on disease progression and underlying molecular mechanisms was explored.

RESULTS

Primary and secondary screenings identified three potential AXL-targeting compounds: Betulin, Clofibric acid, and Isosorbide. Molecular docking analysis revealed that Isosorbide exhibited poor binding affinity with AXL at the molecular level and was excluded from further studies. Betulin and Clofibric acid were found to promote M2 polarization, reduce inflammation, enhance phagocytosis, extend the S phase of the cell cycle, inhibit apoptosis, and improve mitochondrial structure in BV2 cells. In vivo studies demonstrated that Betulin (20 mg/kg) alleviated EAE, while AXL gene knockout reversed its protective effects.

CONCLUSION

This study elucidates the molecular mechanism underlying Betulin's therapeutic effects in MS, both in vitro and in vivo. Betulin exerts its beneficial effects by upregulating the AXL/SOCS3 pathway and inhibiting the JAK2/STAT1 signaling pathway. These findings suggest that Betulin holds significant promise as a potential therapeutic agent for multiple sclerosis.

A comprehensive bibliometric analysis of global research on the role of acrolein in Alzheimer's disease pathogenesis: involvement of amyloid-beta

Background

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive and behavioral decline. Acrolein, an environmental pollutant and endogenous compound, is implicated in AD development. This research employs bibliometric analysis to assess current trends and key areas concerning acrolein-AD interaction.

Methods

The Web of Science was used to extensively review literature on acrolein and AD. Relevant data were systematically gathered and analyzed using VOSviewer, CiteSpace, and an online bibliometric tool.

Results

We identified 120 English publications in this specialized field across 19 journals. The Journal of Alzheimer's Disease was the most prominent. The primary contributors, both in terms of scientific output and influence, were the USA, the University of Kentucky, and Ramassamy C, representing countries/regions, institutions, and authors, respectively. In this field, the primary focus was on thoroughly studying acrolein, its roles, and its mechanisms in AD utilizing both in vivo and in vitro approaches. A significant portion of the research was based on proteomics, revealing complex molecular processes. The main focuses in the field were "oxidative stress," "lipid peroxidation," "amyloid-beta," and "cognitive impairment." Anticipated future research trajectories focus on the involvement of the internalization pathway, covering key areas such as synaptic dysfunction, metabolism, mechanisms, associations, neuroinflammation, inhibitors, tau phosphorylation, acrolein toxicity, brain infarction, antioxidants, chemistry, drug delivery, and dementia. Our analysis also supported our previous hypothesis that acrolein can interact with amyloid-beta to form a protein adduct leading to AD-like pathology and altering natural immune responses.

Conclusion

This study provides a broad and all-encompassing view of the topic, offering valuable insights and guidance to fellow researchers. These emerging directions underscore the continuous exploration of the complexities associated with AD. The analyses and findings aim to enhance our understanding of the intricate relationship between acrolein and AD for future research.

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.

Frontiers of ferroptosis research: An analysis from the top 100 most influential articles in the field

In recent years, ferroptosis has become a research hotspot in programmed cell death. Since the concept of ferroptosis was proposed, a growing number of articles have been published on this topic. Nevertheless, to our knowledge, these ferroptosis-related publications that have received a great deal of attention have not been quantitatively evaluated. In this study, we analyzed the top 100 most influential articles over the past decade through a bibliometric method to characterize the research status and trends in this field. Web of Science Core Collection was searched to identify relevant studies. After being manually screened, the top 100 most cited studies with original data were identified and analyzed. Bibliometric software including VOSviewer and R-Bibliometrix were used to perform visualization analysis. The citation frequency for the top 100 selected articles ranged from 135 to 3603 (326.6 citations on average). These articles originated from 25 countries/regions, with more than half originating from the United States and China. The most frequently nominated author was Stockwell BR from the Columbia University, and of the top 100 articles, 19 listed his name. Three core journals were Nature, Cell and Proceedings of the National Academy of Sciences of the United States of America. In addition to term of ferroptosis, these terms or phrases including cell death, cancer cell, GPX4, pathway, inhibitor, mechanism, iron, lipid peroxidation, resistance, erastin, sorafenib, P53, reactive oxygen species, necroptosis, apoptosis, glutathione peroxidase, ACSL4, autophagy, and SLC7A11 appeared more frequently in the top 100 articles. Overall, although much progress has been made, the research on ferroptosis is still at an early stage. The current attention in this field mainly focuses on potential regulatory mechanism and pathways including key ferroptosis-related genes/molecules, oxidant and antioxidant system, ferroptosis-inducing agents or nanomedicine for cancer therapy, as well as the role of ferroptosis in non-neoplastic disorders. Meanwhile, combination therapeutic strategies targeting ferroptosis in radiotherapy or immunotherapy also deserve further attention.