Early approaches of YKL-40 as a biomarker and therapeutic target for Parkinson's disease

The emerging role of chitinase-3-like-1 protein in neurodegeneration

Neurodegenerative diseases (NDDs) are characterised by the progressive degeneration of neurons in the brain, resulting in impairments in memory, cognition, and motor abilities. Common pathological features include altered energy metabolism, neuroinflammation, death of neurons, aberrant protein aggregation, and synaptic dysfunction. Chitinase-3-like-1 (CHI3-L1) is an evolutionarily conserved protein involved in variety of biological processes such as neuroinflammation, tissue remodelling and angiogenesis. Elevated levels of CHI3-L1 have been detected in the cerebrospinal fluid and plasma of patients with NDDs, suggesting its involvement in disease progression. As a critical regulator of neuroinflammation, CHI3-L1 modulates the activity of astrocyte and microglia, causing the production of pro-inflammatory cytokines that worsens disease progression. In addition to its involvement in disease pathophysiology, it has emerged as a potential biomarker for the diagnosis and monitoring of neurological diseases. However, significant knowledge gaps persist regarding its molecular mechanisms, interactions with inflammatory mediators, and influence on blood-brain barrier integrity. Therefore, this review highlights the emerging role of CHI3-L1 in neurodegeneration and describes future research approaches targeted at unlocking its therapeutic potential in treating NDDs.

Early diagnosis of Parkinson's disease: biomarker study

Parkinson's disease (PD) is a common chronic degenerative disease with age-dependent increasing prevalence in the elderly. Non-motor symptoms include sensory deficiencies, autonomic dysfunction, psychological and cognitive abnormalities; while motor symptoms are bradykinesia, myotonia, resting tremor, and postural balance difficulties. The clinical diagnosis of PD depends mainly on patients' medical history and physical examination. It is highly important to realize early detection of PD, and biomarkers are a valuable tool in this regard. The present study reviewed the findings of researches from the last few years, involving the advancements in the study of PD biomarkers in blood, cerebrospinal fluid, saliva, urine, tears, imaging, and pathology.

Mitigative and neuroprotective effects of Lavandula angustifolia essential oil on serotonin syndrome-induced neurotoxicity in male albino rats

The term serotonin syndrome (SS) is a potentially life-threatening devastating condition triggered by the excessive accumulation of serotonin, often due to an overdose or the concurrent use of multiple serotonergic drugs. Lavandula angustifolia (lavender), a known plant from the Lamiaceae family, is very rich in essential oils, minerals, and tannins. This study aimed to elucidate the detrimental effects of SS on the brain and to evaluate the neuroprotective potential of L. angustifolia essential oil. Male rats were randomly divided into the following groups: control (Group 1); L. angustifolia-treated (Group 2); ondansetron-treated high-dose (Group 3); sertraline-treated high-dose (Group 4); low-dose ondansetron + sertraline-treated (Group 5); high-dose ondansetron + sertraline-treated (Group 6); low-dose ondansetron + sertraline + L. angustifolia-treated (Group 7); and high-dose ondansetron + sertraline + L. angustifolia-treated (Group 8). Neurotransmitter levels, dopamine metabolites, and expressed cytokines were quantified. Additionally, histological assessment of the hippocampus was performed. The results revealed significant disruptions in neurotransmitter and amino acid levels within the hippocampus across the treated groups. Notably, the high-dose ondansetron + sertraline group presented pronounced increases in serotonin, 5-HIAA, and proinflammatory cytokines, resulting in neurotoxicity and pronounced alterations in the hippocampus. Conversely, treatment with L. angustifolia significantly attenuated these neurotoxic effects. The findings suggest that L. angustifolia confers neuroprotection against the deleterious effects of SS, particularly by counteracting the neurotoxic impact of combined serotonin 5-HT3 receptor antagonists and serotonin reuptake inhibitors within the hippocampus. These findings highlight the potential of L. angustifolia as a natural therapeutic agent for mitigating SS-induced neurotoxicity.

Chitinase-3-like-1: a multifaceted player in neuroinflammation and degenerative pathologies with therapeutic implications

Chitinase-3-like-1 (CHI3L1) is an evolutionarily conserved protein involved in key biological processes, including tissue remodeling, angiogenesis, and neuroinflammation. It has emerged as a significant player in various neurodegenerative diseases and brain disorders. Elevated CHI3L1 levels have been observed in neurological conditions such as traumatic brain injury (TBI), Alzheimer's disease (AD), Parkinson's disease (PD), Amyotrophic lateral sclerosis (ALS), Creutzfeldt-Jakob disease (CJD), multiple sclerosis (MS), Neuromyelitis optica (NMO), HIV-associated dementia (HAD), Cerebral ischemic stroke (CIS), and brain tumors. This review explores the role of CHI3L1 in the pathogenesis of these disorders, with a focus on its contributions to neuroinflammation, immune cell infiltration, and neuronal degeneration. As a key regulator of neuroinflammation, CHI3L1 modulates microglia and astrocyte activity, driving the release of proinflammatory cytokines that exacerbate disease progression. In addition to its role in disease pathology, CHI3L1 has emerged as a promising biomarker for the diagnosis and monitoring of brain disorders. Elevated cerebrospinal fluid (CSF) levels of CHI3L1 have been linked to disease severity and cognitive decline, particularly in AD and MS, highlighting its potential for clinical diagnostics. Furthermore, therapeutic strategies targeting CHI3L1, such as small-molecule inhibitors and neutralizing antibodies, have shown promise in preclinical studies, demonstrating reduced neuroinflammation, amyloid plaque accumulation, and improved neuronal survival. Despite its therapeutic potential, challenges remain in developing selective and safe CHI3L1-targeted therapies, particularly in ensuring effective delivery across the blood-brain barrier and mitigating off-target effects. This review addresses the complexities of targeting CHI3L1, highlights its potential in precision medicine, and outlines future research directions aimed at unlocking its full therapeutic potential in treating neurodegenerative diseases and brain pathologies.

Mapping the current trends and hotspots of extracellular vesicles in Alzheimer's disease: a bibliometric analysis

Background

Extracellular vesicles (EVs) have garnered significant attention in Alzheimer's disease (AD) research over the past decade, largely due to their potential in diagnostics and therapeutics. Although the investigation of EVs in AD is a relatively recent endeavor, a comprehensive bibliometric analysis of this rapidly growing field has yet to be conducted.

Methods

This study aims to elucidate and synthesize the relationship between EVs and AD, offering critical insights to guide future research and expand therapeutic possibilities. Over the past 10-15 years, substantial progress has been made in this domain. Through bibliometric techniques, this analysis assesses research performance by examining scientific publications and metrics, including productivity indicators, impact measurements, data mining, and visualization tools.

Results

A total of 602 publications were analyzed using various online platforms for bibliometric analysis. Notably, the number of publications began to increase rapidly in 2018, with China and the United States emerging as leaders in this research area. The National Institute on Aging produced the highest number of publications among institutions. The Journal of Molecular Sciences and the Journal of Biological Chemistry were the most prolific and most frequently cited journals, respectively. Among individual contributors, Dimitrios Kapogiannis was identified as the most productive author, while Edward J. Goetzl was the most co-cited. The most prevalent keywords included "neurodegenerative diseases," "exosomes," "blood biomarkers," "amyloid beta," "microglia," and "tau protein." Current research hotspots involve microRNA dysregulation, oxidative stress, carboxyl-terminal fragments, small EVs, and mesenchymal stem cell-derived EVs, indicating key areas for future research.

Conclusion

Research on microRNA dysregulation, oxidative stress, carboxyl-terminal fragments, small EVs, and mesenchymal stem cell-derived EVs represents a critical frontier in the study of Alzheimer's disease. The role of EV-mediated neuroinflammation in AD is a focal point of ongoing investigation and will likely shape future developments in the field.

Inflammatory Effects and Regulatory Mechanisms of Chitinase-3-like-1 in Multiple Human Body Systems: A Comprehensive Review

Chitinase-3-like-1 (Chi3l1), also known as YKL-40 or BRP-39, is a highly conserved mammalian chitinase with a chitin-binding ability but no chitinase enzymatic activity. Chi3l1 is secreted by various cell types and induced by several inflammatory cytokines. It can mediate a series of cell biological processes, such as proliferation, apoptosis, migration, differentiation, and polarization. Accumulating evidence has verified that Chi3l1 is involved in diverse inflammatory conditions; however, a systematic and comprehensive understanding of the roles and mechanisms of Chi3l1 in almost all human body system-related inflammatory diseases is still lacking. The human body consists of ten organ systems, which are combinations of multiple organs that perform one or more physiological functions. Abnormalities in these human systems can trigger a series of inflammatory environments, posing serious threats to the quality of life and lifespan of humans. Therefore, exploring novel and reliable biomarkers for these diseases is highly important, with Chi3l1 being one such parameter because of its physiological and pathophysiological roles in the development of multiple inflammatory diseases. Reportedly, Chi3l1 plays an important role in diagnosing and determining disease activity/severity/prognosis related to multiple human body system inflammation disorders. Additionally, many studies have revealed the influencing factors and regulatory mechanisms (e.g., the ERK and MAPK pathways) of Chi3l1 in these inflammatory conditions, identifying potential novel therapeutic targets for these diseases. In this review, we comprehensively summarize the potential roles and underlying mechanisms of Chi3l1 in inflammatory disorders of the respiratory, digestive, circulatory, nervous, urinary, endocrine, skeletal, muscular, and reproductive systems, which provides a more systematic understanding of Chi3l1 in multiple human body system-related inflammatory diseases. Moreover, this article summarizes potential therapeutic strategies for inflammatory diseases in these systems on the basis of the revealed roles and mechanisms mediated by Chi3l1.

Impact of Lyophilized Milk Kefir-Based Self-Nanoemulsifying System on Cognitive Enhancement via the Microbiota-Gut-Brain Axis

Chronic inflammatory bowel disorders (IBDs) are characterized by altered intestinal permeability, prompting inflammatory, oxidative stress, and immunological factors. Gut microbiota disorders impact brain function via the bidirectional gut-brain axis, influencing behavior through inflammatory cascades, oxidative stress, and neurotransmitter levels. This study highlights the potential effect of integrating lyophilized milk kefir alone and lyophilized milk kefir as solid carriers loaded with a self-nanoemulsifying self-nanosuspension (SNESNS) of licorice extract on an induced chronic IBD-like model in rats. Licorice-SNESNS was prepared by the homogenization of 30 mg of licorice extract in 1 g of the selected SNEDDS (30% Caraway oil, 60% Tween 20, and 10% propylene glycol (w/w)). Licorice-SNESNS was mixed with milk kefir and then freeze-dried. Dynamic TEM images and the bimodal particle size curve confirmed the formation of the biphasic nanosystems after dilution (nanoemulsion and nanosuspension). Daily oral administration of lyophilized milk kefir (100 mg/kg) loaded with SNESNS (10 mg/kg Caraway oil and 1 mg/kg licorice) restored normal body weight and intestinal mucosa while significantly reducing submucosal inflammatory cell infiltration in induced rats. Importantly, this treatment demonstrated superior efficacy compared to lyophilized milk kefir alone by leading to a more significant alleviation of neurotransmitter levels and improved memory functions, thereby addressing gut-brain axis disorders. Additionally, it normalized fecal microbiome constituents, inflammatory cytokine levels, and oxidative stress in examined tissues and serum. Moreover, daily administration of kefir-loaded SNESNS normalized the disease activity index, alleviated histopathological changes induced by IBD induction, and partially restored the normal gut microbiota. These alterations are associated with improved cognitive functions, attributed to the maintenance of normal neurotransmitter levels and the alleviation of triggered inflammatory factors and oxidative stress levels.

Lectin YKL-40 Level and Telomere Length are Indicators of Insomnia Disorder

OBJECTIVE

To explore the relationship between YKL-40 level, telomere length, and different subtypes of insomnia disorder.

METHODS

A total of 145 individuals suffering from insomnia were enrolled and divided into four groups according to the insomniac subtypes: difficulty initiating sleep, early morning awakening, difficulty maintaining sleep, and mixed symptoms. Eighty healthy controls were also collected at the same time. Peripheral leukocyte genomic DNA was extracted, relative telomere lengths were measured using the real-time quantitative polymerase chain reaction method, and YKL-40 levels were determined using enzyme-linked immunoassay. Logistic regression modeling was used to analyze the correlation between different insomnia subtypes, YKL-40 level, and telomere length.

RESULTS

People with telomere lengths in the lowest tertile were more likely to have trouble falling asleep (odds ratio (OR) 2.13, 95% confidence interval (CI) 1.22-3.63; p = 0.03) and had a higher frequency of mixed symptoms (OR 1.49, 95% CI 1.30-2.81; p = 0.04). People in the highest tertile of YKL-40 level had an increased chance of waking up early (OR 2.98, 95% CI 1.54-5.33; p = 0.01) and more mixed symptoms (OR 1.47, 95% CI 1.22-2.79; p = 0.02). Furthermore, using receiver operating characteristic curve analysis, the area under the curve of YKL-40 level and telomere length was 0.806 and 0.746, respectively.

CONCLUSIONS

Telomere length in patients with difficulty initiating sleep and mixed symptoms was significantly shortened and the level of YKL-40 in people who have early morning awakening and mixed symptoms was significantly increased. Our findings provide the first evidence that leukocyte telomere length and YKL-40 level are individually linked to mixed symptoms.

Exploring the Significance of Microglial Phenotypes and Morphological Diversity in Neuroinflammation and Neurodegenerative Diseases: From Mechanisms to Potential Therapeutic Targets

Studying various microglial phenotypes and their functions in neurodegenerative diseases is crucial due to the intricate nature of their phenomics and their vital immunological role. Microglia undergo substantial phenomic changes, encompassing morphological, transcriptional, and functional aspects, resulting in distinct cell types with diverse structures, functions, properties, and implications. The traditional classification of microglia as ramified, M1 (proinflammatory), or M2 (anti-inflammatory) phenotypes is overly simplistic, failing to capture the wide range of recently identified microglial phenotypes in various brain regions affected by neurodegenerative diseases. Altered and activated microglial phenotypes deviating from the typical ramified structure are significant features of many neurodegenerative conditions. Understanding the precise role of each microglial phenotype is intricate and sometimes contradictory. This review specifically focuses on elucidating recent modifications in microglial phenotypes within neurodegenerative diseases. Recognizing the heterogeneity of microglial phenotypes in diseased states can unveil novel therapeutic strategies for targeting microglia in neurodegenerative diseases. Moreover, the exploration of the use of healthy isolated microglia to mitigate disease progression has provided an innovative perspective. In conclusion, this review discusses the dynamic landscape of mysterious microglial phenotypes, emphasizing the need for a nuanced understanding to pave the way for innovative therapeutic strategies for neurodegenerative diseases.

Recently Updated Role of Chitinase 3-like 1 on Various Cell Types as a Major Influencer of Chronic Inflammation

Chitinase 3-like 1 (also known as CHI3L1 or YKL-40) is a mammalian chitinase that has no enzymatic activity, but has the ability to bind to chitin, the polymer of N-acetylglucosamine (GlcNAc). Chitin is a component of fungi, crustaceans, arthropods including insects and mites, and parasites, but it is completely absent from mammals, including humans and mice. In general, chitin-containing organisms produce mammalian chitinases, such as CHI3L1, to protect the body from exogenous pathogens as well as hostile environments, and it was thought that it had a similar effect in mammals. However, recent studies have revealed that CHI3L1 plays a pathophysiological role by inducing anti-apoptotic activity in epithelial cells and macrophages. Under chronic inflammatory conditions such as inflammatory bowel disease and chronic obstructive pulmonary disease, many groups already confirmed that the expression of CHI3L1 is significantly induced on the apical side of epithelial cells, and activates many downstream pathways involved in inflammation and carcinogenesis. In this review article, we summarize the expression of CHI3L1 under chronic inflammatory conditions in various disorders and discuss the potential roles of CHI3L1 in those disorders on various cell types.

Significance of chitinase-3-like protein 1 in the pathogenesis of inflammatory diseases and cancer

Chitinase-3-like protein 1 (CHI3L1) is a secreted glycoprotein that mediates inflammation, macrophage polarization, apoptosis, and carcinogenesis. The expression of CHI3L1 is strongly upregulated by various inflammatory and immunological diseases, including several cancers, Alzheimer's disease, and atherosclerosis. Several studies have shown that CHI3L1 can be considered as a marker of disease diagnosis, prognosis, disease activity, and severity. In addition, the proinflammatory action of CHI3L1 may be mediated via responses to various proinflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, interleukin-6, and interferon-γ. Therefore, CHI3L1 may contribute to a vast array of inflammatory diseases. However, its pathophysiological and pharmacological roles in the development of inflammatory diseases remain unclear. In this article, we review recent findings regarding the roles of CHI3L1 in the development of inflammatory diseases and suggest therapeutic approaches that target CHI3L1.

The orchestrating role of deteriorating neurons and TREM-1 in crosstalk with SYK in Alzheimer's disease progression and neuroinflammation

Alzheimer's disease (AD) is a progressive type of neurodegenerative disease characterized by successive loss of the conventional structure and functions of neurons. In addition to dead neurons type detected within AD brain tissues, there are a predominantly varying number of deteriorating neurons (DTNs). As the number of deteriorating neurons increases, they exaggerate the release of inflammatory factors and oxidative stress that trigger the cascade of neuroinflammation. Triggering receptor expressed on myeloid cells 1 (TREM-1) which is a transmembrane immune receptor type regularly expressed by phagocytic cells, may act as a stimulating factor for neuroinflammation. Once TREM-1 is activated, it directly activates spleen tyrosine kinase (SYK) downstream signaling cascades, which can be considered an initiating phase for AD pathology and AD progression. Sequentially, SYK activates the pro-inflammatory microglia M1 phenotype which executes several inflammatory actions, leading to neurotoxicity. These released neurotoxins promote neuronal cell death, synaptic dysfunctions, and memory impairments. Thus, the current review outlines the direct etiological and pathologic features of Alzheimer's disease linked with deteriorating neurons, TREM-1, and SYK.

The emerging mechanism behind viral infections and extracellular vesicles hypotheses leading to neuroinflammation and Alzheimer's disease pathology

Despite decades of repeated and intense research, the etiology of sudden Alzheimer's disease (AD) symptoms is still unclear. AD progressive pathology mainly involves neuron damage, depositions of amyloid-beta (Aβ), and hyperphosphorylated tau protein. All these defects are manifested by exaggerated cytokine storm and neuroinflammation leading to irreversible brain damage in the long term. Despite the numerous risks and drawbacks associated with AD, it is believed that there is a hidden unknown causative and predisposing factors for AD. Extracellular vesicles (EVs) are small vesicles released by cells as a type of intercellular communication. Several pieces of evidence support the inclusion of viral components within EVs facilitating their penetration into the blood-brain barrier leading to neuroinflammation. In light of the SARS-CoV-19 pandemic and its related neurological complications, it is mandatory to highlight the possibility and viability of viral infections such as varicella-zoster virus (VZV) and herpes simplex virus (HSV) on the onset of AD. Herein, the author is investigating the potential role of VZV and HSV along with highlighting the suggested route of pathogenesis entry resulting in AD manifestations. Additionally, this review aims to summarize the role of EVs in mediating the central nervous system viral infections leading to AD.