Neuronal guidance signaling in neurodegenerative diseases: Key regulators that function at neuron-glia and neuroimmune interfaces

The nervous system processes a vast amount of information, performing computations that underlie perception, cognition, and behavior. During development, neuronal guidance genes, which encode extracellular cues, their receptors, and downstream signal transducers, organize neural wiring to generate the complex architecture of the nervous system. It is now evident that many of these neuroguidance cues and their receptors are active during development and are also expressed in the adult nervous system. This suggests that neuronal guidance pathways are critical not only for neural wiring but also for ongoing function and maintenance of the mature nervous system. Supporting this view, these pathways continue to regulate synaptic connectivity, plasticity, and remodeling, and overall brain homeostasis throughout adulthood. Genetic and transcriptomic analyses have further revealed many neuronal guidance genes to be associated with a wide range of neurodegenerative and neuropsychiatric disorders. Although the precise mechanisms by which aberrant neuronal guidance signaling drives the pathogenesis of these diseases remain to be clarified, emerging evidence points to several common themes, including dysfunction in neurons, microglia, astrocytes, and endothelial cells, along with dysregulation of neuron-microglia-astrocyte, neuroimmune, and neurovascular interactions. In this review, we explore recent advances in understanding the molecular and cellular mechanisms by which aberrant neuronal guidance signaling contributes to disease pathogenesis through altered cell-cell interactions. For instance, recent studies have unveiled two distinct semaphorin-plexin signaling pathways that affect microglial activation and neuroinflammation. We discuss the challenges ahead, along with the therapeutic potentials of targeting neuronal guidance pathways for treating neurodegenerative diseases. Particular focus is placed on how neuronal guidance mechanisms control neuron-glia and neuroimmune interactions and modulate microglial function under physiological and pathological conditions. Specifically, we examine the crosstalk between neuronal guidance signaling and TREM2, a master regulator of microglial function, in the context of pathogenic protein aggregates. It is well-established that age is a major risk factor for neurodegeneration. Future research should address how aging and neuronal guidance signaling interact to influence an individual's susceptibility to various late-onset neurological diseases and how the progression of these diseases could be therapeutically blocked by targeting neuronal guidance pathways.

Innovative gene delivery systems for retinal disease therapy

The human retina, a complex and highly specialized structure, includes multiple cell types that work synergistically to generate and transmit visual signals. However, genetic predisposition or age-related degeneration can lead to retinal damage that severely impairs vision or causes blindness. Treatment options for retinal diseases are limited, and there is an urgent need for innovative therapeutic strategies. Cell and gene therapies are promising because of the efficacy of delivery systems that transport therapeutic genes to targeted retinal cells. Gene delivery systems hold great promise for treating retinal diseases by enabling the targeted delivery of therapeutic genes to affected cells or by converting endogenous cells into functional ones to facilitate nerve regeneration, potentially restoring vision. This review focuses on two principal categories of gene delivery vectors used in the treatment of retinal diseases: viral and non-viral systems. Viral vectors, including lentiviruses and adeno-associated viruses, exploit the innate ability of viruses to infiltrate cells, which is followed by the introduction of therapeutic genetic material into target cells for gene correction. Lentiviruses can accommodate exogenous genes up to 8 kb in length, but their mechanism of integration into the host genome presents insertion mutation risks. Conversely, adeno-associated viruses are safer, as they exist as episomes in the nucleus, yet their limited packaging capacity constrains their application to a narrower spectrum of diseases, which necessitates the exploration of alternative delivery methods. In parallel, progress has also occurred in the development of novel non-viral delivery systems, particularly those based on liposomal technology. Manipulation of the ratios of hydrophilic and hydrophobic molecules within liposomes and the development of new lipid formulations have led to the creation of advanced non-viral vectors. These innovative systems include solid lipid nanoparticles, polymer nanoparticles, dendrimers, polymeric micelles, and polymeric nanoparticles. Compared with their viral counterparts, non-viral delivery systems offer markedly enhanced loading capacities that enable the direct delivery of nucleic acids, mRNA, or protein molecules into cells. This bypasses the need for DNA transcription and processing, which significantly enhances therapeutic efficiency. Nevertheless, the immunogenic potential and accumulation toxicity associated with non-viral particulate systems necessitates continued optimization to reduce adverse effects in vivo . This review explores the various delivery systems for retinal therapies and retinal nerve regeneration, and details the characteristics, advantages, limitations, and clinical applications of each vector type. By systematically outlining these factors, our goal is to guide the selection of the optimal delivery tool for a specific retinal disease, which will enhance treatment efficacy and improve patient outcomes while paving the way for more effective and targeted therapeutic interventions.

Role of mitophagy in spinal cord ischemia-reperfusion injury

Spinal cord ischemia-reperfusion injury, a severe form of spinal cord damage, can lead to sensory and motor dysfunction. This injury often occurs after traumatic events, spinal cord surgeries, or thoracoabdominal aortic surgeries. The unpredictable nature of this condition, combined with limited treatment options, poses a significant burden on patients, their families, and society. Spinal cord ischemia-reperfusion injury leads to reduced neuronal regenerative capacity and complex pathological processes. In contrast, mitophagy is crucial for degrading damaged mitochondria, thereby supporting neuronal metabolism and energy supply. However, while moderate mitophagy can be beneficial in the context of spinal cord ischemia-reperfusion injury, excessive mitophagy may be detrimental. Therefore, this review aims to investigate the potential mechanisms and regulators of mitophagy involved in the pathological processes of spinal cord ischemia-reperfusion injury. The goal is to provide a comprehensive understanding of recent advancements in mitophagy related to spinal cord ischemia-reperfusion injury and clarify its potential clinical applications.

Neuromodulation techniques for modulating cognitive function: Enhancing stimulation precision and intervention effects

Neuromodulation techniques effectively intervene in cognitive function, holding considerable scientific and practical value in fields such as aerospace, medicine, life sciences, and brain research. These techniques utilize electrical stimulation to directly or indirectly target specific brain regions, modulating neural activity and influencing broader brain networks, thereby regulating cognitive function. Regulating cognitive function involves an understanding of aspects such as perception, learning and memory, attention, spatial cognition, and physical function. To enhance the application of cognitive regulation in the general population, this paper reviews recent publications from the Web of Science to assess the advancements and challenges of invasive and non-invasive stimulation methods in modulating cognitive functions. This review covers various neuromodulation techniques for cognitive intervention, including deep brain stimulation, vagus nerve stimulation, and invasive methods using microelectrode arrays. The non-invasive techniques discussed include transcranial magnetic stimulation, transcranial direct current stimulation, transcranial alternating current stimulation, transcutaneous electrical acupoint stimulation, and time interference stimulation for activating deep targets. Invasive stimulation methods, which are ideal for studying the pathogenesis of neurological diseases, tend to cause greater trauma and have been less researched in the context of cognitive function regulation. Non-invasive methods, particularly newer transcranial stimulation techniques, are gentler and more appropriate for regulating cognitive functions in the general population. These include transcutaneous acupoint electrical stimulation using acupoints and time interference methods for activating deep targets. This paper also discusses current technical challenges and potential future breakthroughs in neuromodulation technology. It is recommended that neuromodulation techniques be combined with neural detection methods to better assess their effects and improve the accuracy of non-invasive neuromodulation. Additionally, researching closed-loop feedback neuromodulation methods is identified as a promising direction for future development.

Metabolic reprogramming of astrocytes: Emerging roles of lactate

Lactate serves as a key energy metabolite in the central nervous system, facilitating essential brain functions, including energy supply, signaling, and epigenetic modulation. Moreover, it links epigenetic modifications with metabolic reprogramming. Nonetheless, the specific mechanisms and roles of this connection in astrocytes remain unclear. Therefore, this review aims to explore the role and specific mechanisms of lactate in the metabolic reprogramming of astrocytes in the central nervous system. The close relationship between epigenetic modifications and metabolic reprogramming was discussed. Therapeutic strategies for targeting metabolic reprogramming in astrocytes in the central nervous system were also outlined to guide future research in central nervous system diseases. In the nervous system, lactate plays an essential role. However, its mechanism of action as a bridge between metabolic reprogramming and epigenetic modifications in the nervous system requires future investigation. The involvement of lactate in epigenetic modifications is currently a hot research topic, especially in lactylation modification, a key determinant in this process. Lactate also indirectly regulates various epigenetic modifications, such as N6-methyladenosine, acetylation, ubiquitination, and phosphorylation modifications, which are closely linked to several neurological disorders. In addition, exploring the clinical applications and potential therapeutic strategies of lactic acid provides new insights for future neurological disease treatments.

Insights into the transcriptomic heterogeneity of brain endothelial cells in normal aging and Alzheimer's disease

Drug development for Alzheimer's disease is extremely challenging, as demonstrated by the repeated failures of amyloid-β-targeted therapeutics and the controversies surrounding the amyloid-β cascade hypothesis. More recently, advances in the development of Lecanemab, an anti-amyloid-β monoclonal antibody, have shown positive results in reducing brain A burden and slowing cognitive decline in patients with early-stage Alzheimer's disease in the Phase III clinical trial (Clarity Alzheimer's disease). Despite these promising results, side effects such as amyloid-related imaging abnormalities (ARIA) may limit its usage. ARIA can manifest as ARIA-E (cerebral edema or effusions) and ARIA-H (microhemorrhages or superficial siderosis) and is thought to be caused by increased vascular permeability due to inflammatory responses, leading to leakages of blood products and protein-rich fluid into brain parenchyma. Endothelial dysfunction is an early pathological feature of Alzheimer's disease, and the blood-brain barrier becomes increasingly leaky as the disease progresses. In addition, APOE4, the strongest genetic risk factor for Alzheimer's disease, is associated with higher vascular amyloid burden, increased ARIA incidence, and accelerated blood-brain barrier disruptions. These interconnected vascular abnormalities highlight the importance of vascular contributions to the pathophysiology of Alzheimer's disease. Here, we will closely examine recent research evaluating the heterogeneity of brain endothelial cells in the microvasculature of different brain regions and their relationships with Alzheimer's disease progression.

Is age-related myelinodegenerative change an initial risk factor of neurodegenerative diseases?

Myelination, the continuous ensheathment of neuronal axons, is a lifelong process in the nervous system that is essential for the precise, temporospatial conduction of action potentials between neurons. Myelin also provides intercellular metabolic support to axons. Even minor disruptions in the integrity of myelin can impair neural performance and increase susceptibility to neurological diseases. In fact, myelin degeneration is a well-known neuropathological condition that is associated with normal aging and several neurodegenerative diseases, including multiple sclerosis and Alzheimer's disease. In the central nervous system, compact myelin sheaths are formed by fully mature oligodendrocytes. However, the entire oligodendrocyte lineage is susceptible to changes in the biological microenvironment and other risk factors that arise as the brain ages. In addition to their well-known role in action potential propagation, oligodendrocytes also provide intercellular metabolic support to axons by transferring energy metabolites and delivering exosomes. Therefore, myelin degeneration in the aging central nervous system is a significant contributor to the development of neurodegenerative diseases. Interventions that mitigate age-related myelin degeneration can improve neurological function in aging individuals. In this review, we investigate the changes in myelin that are associated with aging and their underlying mechanisms. We also discuss recent advances in understanding how myelin degeneration in the aging brain contributes to neurodegenerative diseases and explore the factors that can prevent, slow down, or even reverse age-related myelin degeneration. Future research will enhance our understanding of how reducing age-related myelin degeneration can be used as a therapeutic target for delaying or preventing neurodegenerative diseases.

Mesenchymal stem cell-derived small extracellular vesicles enhance the therapeutic effect of retinal progenitor cells in retinal degenerative disease rats

JOURNAL/nrgr/04.03/01300535-202602000-00050/figure1/v/2025-05-05T160104Z/r/image-tiff Our previous study demonstrated that combined transplantation of bone marrow mesenchymal stem cells and retinal progenitor cells in rats has therapeutic effects on retinal degeneration that are superior to transplantation of retinal progenitor cells alone. Bone marrow mesenchymal stem cells regulate and interact with various cells in the retinal microenvironment by secreting neurotrophic factors and extracellular vesicles. Small extracellular vesicles derived from bone marrow mesenchymal stem cells, which offer low immunogenicity, minimal tumorigenic risk, and ease of transportation, have been utilized in the treatment of various neurological diseases. These vesicles exhibit various activities, including anti-inflammatory actions, promotion of tissue repair, and immune regulation. Therefore, novel strategies using human retinal progenitor cells combined with bone marrow mesenchymal stem cell-derived small extracellular vesicles may represent an innovation in stem cell therapy for retinal degeneration. In this study, we developed such an approach utilizing retinal progenitor cells combined with bone marrow mesenchymal stem cell-derived small extracellular vesicles to treat retinal degeneration in Royal College of Surgeons rats, a genetic model of retinal degeneration. Our findings revealed that the combination of bone marrow mesenchymal stem cell-derived small extracellular vesicles and retinal progenitor cells significantly improved visual function in these rats. The addition of bone marrow mesenchymal stem cell-derived small extracellular vesicles as adjuvants to stem cell transplantation with retinal progenitor cells enhanced the survival, migration, and differentiation of the exogenous retinal progenitor cells. Concurrently, these small extracellular vesicles inhibited the activation of regional microglia, promoted the migration of transplanted retinal progenitor cells to the inner nuclear layer of the retina, and facilitated their differentiation into photoreceptors and bipolar cells. These findings suggest that bone marrow mesenchymal stem cell-derived small extracellular vesicles potentiate the therapeutic efficacy of retinal progenitor cells in retinal degeneration by promoting their survival and differentiation.

Grafts of hydrogel-embedded electrically stimulated subventricular stem cells into the stroke cavity improves functional recovery of mice

JOURNAL/nrgr/04.03/01300535-202602000-00039/figure1/v/2025-05-05T160104Z/r/image-tiff The major aim of stroke therapy is to stimulate brain repair and improve behavioral recovery after cerebral ischemia. One option is to stimulate endogenous neurogenesis in the subventricular zone and direct the newly formed neurons to the damaged area. However, only a small percentage of these neurons survive, and many do not reach the damaged area, possibly because the corpus callosum impedes the migration of subventricular zone-derived stem cells into the lesioned cortex. A second major obstacle to stem cell therapy is the strong inflammatory reaction induced by cerebral ischemia, whereby the associated phagocytic activity of brain macrophages removes both therapeutic cells and/or cell-based drug carriers. To address these issues, neurogenesis was electrically stimulated in the subventricular zone, followed by isolation of proliferating cells, including newly formed neurons, which were subsequently mixed with a nutritional hydrogel. This mixture was then transferred to the stroke cavity of day 14 post-stroke mice. We found that the performance of the treated animals improved in behavioral tests, including novel object, open field, hole board, grooming, and "time-to-feel" adhesive tape tests. Furthermore, immunostaining revealed that the stem cell marker nestin, the neuroepithelial marker Mash1, and the immature neuronal marker doublecortin-positive cells survived in the transplanted area for 2 weeks, possibly due to reduced phagocytic activity and supportive angiogenesis. These results clearly indicate that the transplantation of committed subventricular zone stem cells combined with a protective nutritional gel directly into the infarct cavity after the peak of stroke-induced neuroinflammation represents a feasible approach to improve neurorestoration after cerebral ischemia.

Optogenetic approaches for neural tissue regeneration: A review of basic optogenetic principles and target cells for therapy

Optogenetics has revolutionized the field of neuroscience by enabling precise control of neural activity through light-sensitive proteins known as opsins. This review article discusses the fundamental principles of optogenetics, including the activation of both excitatory and inhibitory opsins, as well as the development of optogenetic models that utilize recombinant viral vectors. A considerable portion of the article addresses the limitations of optogenetic tools and explores strategies to overcome these challenges. These strategies include the use of adeno-associated viruses, cell-specific promoters, modified opsins, and methodologies such as bioluminescent optogenetics. The application of viral recombinant vectors, particularly adeno-associated viruses, is emerging as a promising avenue for clinical use in delivering opsins to target cells. This trend indicates the potential for creating tools that offer greater flexibility and accuracy in opsin delivery. The adaptations of these viral vectors provide advantages in optogenetic studies by allowing for the restricted expression of opsins through cell-specific promoters and various viral serotypes. The article also examines different cellular targets for optogenetics, including neurons, astrocytes, microglia, and Schwann cells. Utilizing specific promoters for opsin expression in these cells is essential for achieving precise and efficient stimulation. Research has demonstrated that optogenetic stimulation of both neurons and glial cells-particularly the distinct phenotypes of microglia, astrocytes, and Schwann cells-can have therapeutic effects in neurological diseases. Glial cells are increasingly recognized as important targets for the treatment of these disorders. Furthermore, the article emphasizes the emerging field of bioluminescent optogenetics, which combines optogenetic principles with bioluminescent proteins to visualize and manipulate neural activity in real time. By integrating molecular genetics techniques with bioluminescence, researchers have developed methods to monitor neuronal activity efficiently and less invasively, enhancing our understanding of central nervous system function and the mechanisms of plasticity in neurological disorders beyond traditional neurobiological methods. Evidence has shown that optogenetic modulation can enhance motor axon regeneration, achieve complete sensory reinnervation, and accelerate the recovery of neuromuscular function. This approach also induces complex patterns of coordinated motor neuron activity and promotes neural reorganization. Optogenetic approaches hold immense potential for therapeutic interventions in the central nervous system. They enable precise control of neural circuits and may offer new treatments for neurological disorders, particularly spinal cord injuries, peripheral nerve injuries, and other neurodegenerative diseases.

Tropism-shifted AAV-PHP.eB-mediated bFGF gene therapy promotes varied neurorestoration after ischemic stroke in mice

JOURNAL/nrgr/04.03/01300535-202602000-00040/figure1/v/2025-05-05T160104Z/r/image-tiff AAV-PHP.eB is an artificial adeno-associated virus (AAV) that crosses the blood-brain barrier and targets neurons more efficiently than other AAVs when administered systematically. While AAV-PHP.eB has been used in various disease models, its cellular tropism in cerebrovascular diseases remains unclear. In the present study, we aimed to elucidate the tropism of AAV-PHP.eB for different cell types in the brain in a mouse model of ischemic stroke and evaluate its effectiveness in mediating basic fibroblast growth factor ( bFGF ) gene therapy. Mice were injected intravenously with AAV-PHP.eB either 14 days prior to (pre-stroke) or 1 day following (post-stroke) transient middle cerebral artery occlusion. Notably, we observed a shift in tropism from neurons to endothelial cells with post-stroke administration of AAV-PHP.eB-mNeonGreen (mNG). This endothelial cell tropism correlated strongly with expression of the endothelial membrane receptor lymphocyte antigen 6 family member A (Ly6A). Furthermore, AAV-PHP.eB-mediated overexpression of bFGF markedly improved neurobehavioral outcomes and promoted long-term neurogenesis and angiogenesis post-ischemic stroke. Our findings underscore the significance of considering potential tropism shifts when utilizing AAV-PHP.eB-mediated gene therapy in neurological diseases and suggest a promising new strategy for bFGF gene therapy in stroke treatment.

Novel insights into non-coding RNAs and their role in hydrocephalus

A large body of evidence has highlighted the role of non-coding RNAs in neurodevelopment and neuroinflammation. This evidence has led to increasing speculation that non-coding RNAs may be involved in the pathophysiological mechanisms underlying hydrocephalus, one of the most common neurological conditions worldwide. In this review, we first outline the basic concepts and incidence of hydrocephalus along with the limitations of existing treatments for this condition. Then, we outline the definition, classification, and biological role of non-coding RNAs. Subsequently, we analyze the roles of non-coding RNAs in the formation of hydrocephalus in detail. Specifically, we have focused on the potential significance of non-coding RNAs in the pathophysiology of hydrocephalus, including glymphatic pathways, neuroinflammatory processes, and neurological dysplasia, on the basis of the existing evidence. Lastly, we review the potential of non-coding RNAs as biomarkers of hydrocephalus and for the creation of innovative treatments.

Stress granules: Guardians of cellular health and triggers of disease

Stress granules are membraneless organelles that serve as a protective cellular response to external stressors by sequestering non-translating messenger RNAs (mRNAs) and regulating protein synthesis. Stress granules formation mechanism is conserved across species, from yeast to mammals, and they play a critical role in minimizing cellular damage during stress. Composed of heterogeneous ribonucleoprotein complexes, stress granules are enriched not only in mRNAs but also in noncoding RNAs and various proteins, including translation initiation factors and RNA-binding proteins. Genetic mutations affecting stress granule assembly and disassembly can lead to abnormal stress granule accumulation, contributing to the progression of several diseases. Recent research indicates that stress granule dynamics are pivotal in determining their physiological and pathological functions, with acute stress granule formation offering protection and chronic stress granule accumulation being detrimental. This review focuses on the multifaceted roles of stress granules under diverse physiological conditions, such as regulation of mRNA transport, mRNA translation, apoptosis, germ cell development, phase separation processes that govern stress granule formation, and their emerging implications in pathophysiological scenarios, such as viral infections, cancer, neurodevelopmental disorders, neurodegeneration, and neuronal trauma.

A single-cell landscape of the regenerating spinal cord of zebrafish

JOURNAL/nrgr/04.03/01300535-202602000-00046/figure1/v/2025-05-05T160104Z/r/image-tiff Unlike mammals, zebrafish possess a remarkable ability to regenerate their spinal cord after injury, making them an ideal vertebrate model for studying regeneration. While previous research has identified key cell types involved in this process, the underlying molecular and cellular mechanisms remain largely unexplored. In this study, we used single-cell RNA sequencing to profile distinct cell populations at different stages of spinal cord injury in zebrafish. Our analysis revealed that multiple subpopulations of neurons showed persistent activation of genes associated with axonal regeneration post injury, while molecular signals promoting growth cone collapse were inhibited. Radial glial cells exhibited significant proliferation and differentiation potential post injury, indicating their intrinsic roles in promoting neurogenesis and axonal regeneration, respectively. Additionally, we found that inflammatory factors rapidly decreased in the early stages following spinal cord injury, creating a microenvironment permissive for tissue repair and regeneration. Furthermore, oligodendrocytes lost maturity markers while exhibiting increased proliferation following injury. These findings demonstrated that the rapid and orderly regulation of inflammation, as well as the efficient proliferation and redifferentiation of new neurons and glial cells, enabled zebrafish to reconstruct the spinal cord. This research provides new insights into the cellular transitions and molecular programs that drive spinal cord regeneration, offering promising avenues for future research and therapeutic strategies.

Sox2-overexpressing neural stem cells alleviate ventricular enlargement and neurological dysfunction in posthemorrhagic hydrocephalus

JOURNAL/nrgr/04.03/01300535-202602000-00045/figure1/v/2025-05-05T160104Z/r/image-tiff Neural stem cells (NSCs) have the potential for self-renewal and multidirectional differentiation, and their transplantation has achieved good efficacy in a variety of diseases. However, only 1%-10% of transplanted NSCs survive in the ischemic and hypoxic microenvironment of posthemorrhagic hydrocephalus. Sox2 is an important factor for NSCs to maintain proliferation. Therefore, Sox2-overexpressing NSCs (NSCSox2) may be more successful in improving neurological dysfunction after posthemorrhagic hydrocephalus. In this study, human NSCSox2 was transplanted into a posthemorrhagic hydrocephalus mouse model, and retinoic acid was administered to further promote NSC differentiation. The results showed that NSCSox2 attenuated the ventricular enlargement caused by posthemorrhagic hydrocephalus and improved neurological function. NSCSox2 also promoted nerve regeneration, inhibited neuroinflammation and promoted M2 polarization (anti-inflammatory phenotype), thereby reducing cerebrospinal fluid secretion in choroid plexus. These findings suggest that NSCSox2 rescued ventricular enlargement and neurological dysfunction induced by posthemorrhagic hydrocephalus through neural regeneration and modulation of inflammation.

Bromodomain-containing protein 4 knockdown promotes neuronal ferroptosis in a mouse model of subarachnoid hemorrhage

JOURNAL/nrgr/04.03/01300535-202602000-00041/figure1/v/2025-05-05T160104Z/r/image-tiff Neuronal cell death is a common outcome of multiple pathophysiological processes and a key factor in neurological dysfunction after subarachnoid hemorrhage. Neuronal ferroptosis in particular plays an important role in early brain injury. Bromodomain-containing protein 4, a member of the bromo and extraterminal domain family of proteins, participated in multiple cell death pathways, but the mechanisms by which it regulates ferroptosis remain unclear. The primary aim of this study was to investigate how bromodomain-containing protein 4 affects neuronal ferroptosis following subarachnoid hemorrhage in vivo and in vitro . Our findings revealed that endogenous bromodomain-containing protein 4 co-localized with neurons, and its expression was decreased 48 hours after subarachnoid hemorrhage of the cerebral cortex in vivo . In addition, ferroptosis-related pathways were activated in vivo and in vitro after subarachnoid hemorrhage. Targeted inhibition of bromodomain-containing protein 4 in neurons increased lipid peroxidation and intracellular ferrous iron accumulation via ferritinophagy and ultimately led to neuronal ferroptosis. Using cleavage under targets and tagmentation analysis, we found that bromodomain-containing protein 4 enrichment in the Raf-1 promoter region decreased following oxyhemoglobin stimulation in vitro . Furthermore, treating bromodomain-containing protein 4-knockdown HT-22 cell lines with GW5074, a Raf-1 inhibitor, exacerbated neuronal ferroptosis by suppressing the Raf-1/ERK1/2 signaling pathway. Moreover, targeted inhibition of neuronal bromodomain-containing protein 4 exacerbated early and long-term neurological function deficits after subarachnoid hemorrhage. Our findings suggest that bromodomain-containing protein 4 may have neuroprotective effects after subarachnoid hemorrhage, and that inhibiting ferroptosis could help treat subarachnoid hemorrhage.

Recent advances in immunotherapy targeting amyloid-beta and tauopathies in Alzheimer's disease

Alzheimer's disease, a devastating neurodegenerative disorder, is characterized by progressive cognitive decline, primarily due to amyloid-beta protein deposition and tau protein phosphorylation. Effectively reducing the cytotoxicity of amyloid-beta42 aggregates and tau oligomers may help slow the progression of Alzheimer's disease. Conventional drugs, such as donepezil, can only alleviate symptoms and are not able to prevent the underlying pathological processes or cognitive decline. Currently, active and passive immunotherapies targeting amyloid-beta and tau have shown some efficacy in mice with asymptomatic Alzheimer's disease and other transgenic animal models, attracting considerable attention. However, the clinical application of these immunotherapies demonstrated only limited efficacy before the discovery of lecanemab and donanemab. This review first discusses the advancements in the pathogenesis of Alzheimer's disease and active and passive immunotherapies targeting amyloid-beta and tau proteins. Furthermore, it reviews the advantages and disadvantages of various immunotherapies and considers their future prospects. Although some antibodies have shown promise in patients with mild Alzheimer's disease, substantial clinical data are still lacking to validate their effectiveness in individuals with moderate Alzheimer's disease.

Chemical exchange saturation transfer MRI for neurodegenerative diseases: An update on clinical and preclinical studies

Chemical exchange saturation transfer magnetic resonance imaging is an advanced imaging technique that enables the detection of compounds at low concentrations with high sensitivity and spatial resolution and has been extensively studied for diagnosing malignancy and stroke. In recent years, the emerging exploration of chemical exchange saturation transfer magnetic resonance imaging for detecting pathological changes in neurodegenerative diseases has opened up new possibilities for early detection and repetitive scans without ionizing radiation. This review serves as an overview of chemical exchange saturation transfer magnetic resonance imaging with detailed information on contrast mechanisms and processing methods and summarizes recent developments in both clinical and preclinical studies of chemical exchange saturation transfer magnetic resonance imaging for Alzheimer's disease, Parkinson's disease, multiple sclerosis, and Huntington's disease. A comprehensive literature search was conducted using databases such as PubMed and Google Scholar, focusing on peer-reviewed articles from the past 15 years relevant to clinical and preclinical applications. The findings suggest that chemical exchange saturation transfer magnetic resonance imaging has the potential to detect molecular changes and altered metabolism, which may aid in early diagnosis and assessment of the severity of neurodegenerative diseases. Although promising results have been observed in selected clinical and preclinical trials, further validations are needed to evaluate their clinical value. When combined with other imaging modalities and advanced analytical methods, chemical exchange saturation transfer magnetic resonance imaging shows potential as an in vivo biomarker, enhancing the understanding of neuropathological mechanisms in neurodegenerative diseases.

Measuring glymphatic function: Assessing the toolkit

Glymphatic flow has been proposed to clear brain waste while we sleep. Cerebrospinal fluid moves from periarterial to perivenous spaces through the parenchyma, with subsequent cerebrospinal fluid drainage to dural lymphatics. Glymphatic disruption is associated with neurological conditions such as Alzheimer's disease and traumatic brain injury. Therefore, investigating its structure and function may improve understanding of pathophysiology. The recent controversy on whether glymphatic flow increases or decreases during sleep demonstrates that the glymphatic hypothesis remains contentious. However, discrepancies between different studies could be due to limitations of the specific techniques used and confounding factors. Here, we review the methods used to study glymphatic function and provide a toolkit from which researchers can choose. We conclude that tracer analysis has been useful, ex vivo techniques are unreliable, and in vivo imaging is still limited. Finally, we explore the potential for future methods and highlight the need for in vitro models, such as microfluidic devices, which may address technique limitations and enable progression of the field.

Tryptophan metabolism and ischemic stroke: An intricate balance

Ischemic stroke, which is characterized by hypoxia and ischemia, triggers a cascade of injury responses, including neurotoxicity, inflammation, oxidative stress, disruption of the blood-brain barrier, and neuronal death. In this context, tryptophan metabolites and enzymes, which are synthesized through the kynurenine and 5-hydroxytryptamine pathways, play dual roles. The delicate balance between neurotoxic and neuroprotective substances is a crucial factor influencing the progression of ischemic stroke. Neuroprotective metabolites, such as kynurenic acid, exert their effects through various mechanisms, including competitive blockade of N-methyl-D-aspartate receptors, modulation of α7 nicotinic acetylcholine receptors, and scavenging of reactive oxygen species. In contrast, neurotoxic substances such as quinolinic acid can hinder the development of vascular glucose transporter proteins, induce neurotoxicity mediated by reactive oxygen species, and disrupt mitochondrial function. Additionally, the enzymes involved in tryptophan metabolism play major roles in these processes. Indoleamine 2,3-dioxygenase in the kynurenine pathway and tryptophan hydroxylase in the 5-hydroxytryptamine pathway influence neuroinflammation and brain homeostasis. Consequently, the metabolites generated through tryptophan metabolism have substantial effects on the development and progression of ischemic stroke. Stroke treatment aims to restore the balance of various metabolite levels; however, precise regulation of tryptophan metabolism within the central nervous system remains a major challenge for the treatment of ischemic stroke. Therefore, this review aimed to elucidate the complex interactions between tryptophan metabolites and enzymes in ischemic stroke and develop targeted therapies that can restore the delicate balance between neurotoxicity and neuroprotection.

Autophagy machinery as exploited by viruses

Viruses adapt and modulate cellular pathways to allow their replication in host cells. The catabolic pathway of macroautophagy, for simplicity referred to as autophagy, is no exception. In this review, we discuss anti-viral functions of both autophagy and select components of the autophagy machinery, and how viruses have evaded them. Some viruses use the membrane remodeling ability of the autophagy machinery to build their replication compartments in the cytosol or efficiently egress from cells in a non-lytic fashion. Some of the autophagy machinery components and their remodeled membranes can even be found in viral particles as envelopes or single membranes around virus packages that protect them during spreading and transmission. Therefore, studies on autophagy regulation by viral infections can reveal functions of the autophagy machinery beyond lysosomal degradation of cytosolic constituents. Furthermore, they can also pinpoint molecular interactions with which the autophagy machinery can most efficiently be manipulated, and this may be relevant to develop effective disease treatments based on autophagy modulation.

Fractional exhaled nitric oxide in a respiratory healthy general population through the lifespan

INTRODUCTION AND OBJECTIVES

The fractional exhaled fraction of nitric oxide (FeNO) is used in clinical practice for asthma diagnosis, phenotyping, and therapeutic management. Therefore, accurate thresholds are crucial. The normal FeNO values over lifespan in a respiratory healthy population and the factors related to them remain unclear.

MATERIALS AND METHODS

We determined FeNO levels in 2,251 respiratory healthy, non-atopic, and non-smoking participants from the Lung, hEart, sociAl, boDy (LEAD) cohort, a general population, observational cohort study of participants aged 6-82 years in Austria.

RESULTS

The median FeNO value in the total study population was 13.0 [interquartile range: 9.0, 20.0] ppb, increases with age, and, except in young participants (<18 years: 9.0 [7.0, 12.0], ≥18 years: 15.0 [11.0, 22.0]), it was significantly lower in females versus males. Multiple regression analyses showed that body height and blood eosinophil counts were associated with higher FeNO levels, both in children/adolescents and adults. In children/adolescents, FeNO values were positively associated with total IgE levels, FEV1/FVC ratio, and urban living. In adults, FeNO was positively associated with age and negatively associated with the presence of cardiovascular and ischaemic vascular disease.

CONCLUSIONS

We identified the normal FeNO ranges within a respiratory healthy population at different age ranges and associated factors. Collectively, they serve as a reference to frame FeNO values in clinical practice.

German Asthma Net: Characterisation of responders to anti-IL-5 and anti-IL-5(R) therapy

INTRODUCTION

Previous studies of anti-IL-5/IL-5(R) therapies in severe asthma found that response was mainly predicted by indicators of good baseline disease control. However, long-term response predictors remain unclear.

METHODS

Responders to anti-IL-5/IL-5(R) therapy in the well-characterised, real-life, international German Asthma Net (GAN) registry were analysed using regression analyses. Response was defined by ≥50% reduction in exacerbations or corticosteroid dose, super-response by a complete stop of both, and remission additionally by controlled asthma (ACT score≥20).

RESULTS

Seventy-seven percent of 347 patients (55% female, 56.6±12.3 years, follow-up 20.3±13 months) were responders and showed improved exacerbation rates, asthma control, and corticosteroid treatment reduction. Response was independently predicted by inhaled corticosteroid dose (odds ratio [OR] 1.5; p = 0.014), exacerbation rate (OR 1.2; p = 0.009), and treatment duration (OR 1.05, p = 0.023). Univariately, blood eosinophil counts notably predicted response (OR 12.4; p = 0.004). Super-response was inversely associated with corticosteroid dependence and depression. Remission was associated with the absence of systemic corticosteroids, better asthma control, and FEV1 in litre.

CONCLUSIONS

These results underscore that long-term anti-IL-5/IL-5(R) therapy reduces exacerbation and corticosteroid burden, especially in patients with severe disease and high type 2 inflammatory burden. Contrastingly, low baseline corticosteroid use and markers of good asthma control predicted remission and super-responder status.

Issue 4 - Impact of air pollution on COVID-19 mortality and morbidity: An epidemiological and mechanistic review

Air pollution is a major global environment and health concern. Recent studies have suggested an association between air pollution and COVID-19 mortality and morbidity. In this context, a close association between increased levels of air pollutants such as particulate matter ≤2.5 to 10 µM, ozone and nitrogen dioxide and SARS-CoV-2 infection, hospital admissions and mortality due to COVID 19 has been reported. Air pollutants can make individuals more susceptible to SARS-CoV-2 infection by inducing the expression of proteins such as angiotensin converting enzyme (ACE)2 and transmembrane protease, serine 2 (TMPRSS2) that are required for viral entry into the host cell, while causing impairment in the host defence system by damaging the epithelial barrier, muco-ciliary clearance, inhibiting the antiviral response and causing immune dysregulation. The aim of this review is to report the epidemiological evidence on impact of air pollutants on COVID 19 in an up-to-date manner, as well as to provide insights on in vivo and in vitro mechanisms.

Closing the loops: chromatin loop dynamics after DNA damage

Chromatin is a dynamic polymer in constant motion. These motions are heterogeneous between cells and within individual cell nuclei and are profoundly altered in response to DNA damage. The shifts in chromatin motions following genomic insults depend on the temporal and physical scales considered. They are also distinct in damaged and undamaged regions. In this review, we emphasize the role of chromatin tethering and loop formation in chromatin dynamics, with the view that pulsing loops are key contributors to chromatin motions. Chromatin tethers likely mediate micron-scale chromatin coherence predicted by polymer models and measured experimentally, and we propose that remodeling of the tethers in response to DNA breaks enables uncoupling of damaged and undamaged chromatin regions.

Analysis of how antigen mutations disrupt antibody binding interactions toward enabling rapid and reliable antibody repurposing

Antibody repurposing is the process of changing a known antibody so that it binds to a mutated antigen. One of the findings to emerge from the Coronavirus Disease 2019 (COVID-19) pandemic was that it was possible to repurpose neutralizing antibodies for Severe Acute Respiratory Syndrome, a related disease, to work for COVID-19. Thus, antibody repurposing is a possible pathway to prepare for and respond to future pandemics, as well as personalizing cancer therapies. For antibodies to be successfully repurposed, it is necessary to know both how antigen mutations disrupt their binding and how they should be mutated to recover binding, with this work describing an analysis to address the first of these topics. Every possible antigen point mutation in the interface of 246 antibody-protein complexes were analyzed using the Rosetta molecular mechanics force field. The results highlight a number of features of how antigen mutations affect antibody binding, including the effects of mutating critical hotspot residues versus other positions, how many mutations are necessary to be likely to disrupt binding, the prevalence of indirect effects of mutations on binding, and the relative importance of changing attractive versus repulsive energies. These data are expected to be useful in guiding future antibody repurposing experiments.

Circulating cytokine associations with clinical outcomes in melanoma patients treated with combination nivolumab plus ipilimumab

Nivolumab plus ipilimumab (aCTLA-4/aPD-1) combination therapy has significantly improved clinical outcomes in patients with metastatic melanoma, with 50%-60% of patients responding to treatment, but predictors of response are poorly characterized. We hypothesized that circulating cytokines and peripheral white blood cells may predict response to therapy and evaluated 15 cytokines and complete blood counts (CBC with differentials) from 89 patients with advanced melanoma treated with combination therapy from three points in time: pre-treatment, one month and approximately three months after starting therapy. Clinical endpoints evaluated included durable clinical benefit (DCB), progression-free survival (PFS), and overall survival (OS). A parsimonious predictive model was developed to identify cytokines predictors of response to combination therapy. In this study, we found that pre-treatment, patients with DCB had higher IL-23, lower CXCL6, and lower IL-10 levels. Lower NLR one month after starting therapy predicted better PFS and OS, primarily driven by an increase in absolute lymphocytes. A multivariate model demonstrated that baseline CXCL6, IL-10, IL-23 were independent predictors of therapy response, and the combined model has reached an area under the curve (AUC) of 0.79 in prediction of response to combination therapy. Our study identified baseline CXCL6, IL-23, and IL-10 as predictors of response to aCTLA4/aPD1 combination therapy among patients with metastatic melanoma. This study also provides a framework for identifying patients who are likely to respond to combination ICB, as well as a subset of patients with high risk of developing resistance and are thus in need of alternative therapeutic options, such as clinical trials.

Knockdown of NDUFAF6 inhibits breast cancer progression via promoting mitophagy and apoptosis

BACKGROUND

While NDUFAF6 is implicated in breast cancer, its specific role remains unclear.

METHODS

The expression levels and prognostic significance of NDUFAF6 in breast cancer were assessed using The Cancer Genome Atlas, Gene Expression Omnibus, Kaplan-Meier plotter and cBio-Portal databases. We knocked down NDUFAF6 in breast cancer cells using small interfering RNA and investigated its effects on cell proliferation and migration ability. We performed gene expression analysis and validated key findings using protein analysis. We also assessed mitochondrial activity and cellular metabolism.

RESULTS

NDUFAF6 was highly expressed in breast cancer, which was associated with a poorer prognosis. Knockdown of NDUFAF6 reduced the proliferation and migration ability of breast cancer cells. Transcriptome analysis revealed 2,101 differentially expressed genes enriched in apoptosis and mitochondrial signaling pathways. Western blot results showed NDUFAF6 knockdown enhanced apoptosis. In addition, differential gene enrichment analysis was related to mitochondrial signaling pathways, and western blot results verified that mitophagy was enhanced in NDUFAF6 knockdown breast cancer cells. JC-1 assay also showed that mitochondrial dysfunction and reactive oxygen species content were increased after knocking down NDUFAF6. In addition, basal and maximal mitochondrial oxygen consumption decreased, and intracellular glycogen content increased.

CONCLUSIONS

Knockdown of NDUFAF6 resulted in apoptosis and mitophagy in breast cancer cells and NDUFAF6 may be a potential molecular target for breast cancer therapy.

The microbiota-derived bile acid taurodeoxycholic acid improves hepatic cholesterol levels in mice with cancer cachexia

Alterations in bile acid profile and pathways contribute to hepatic inflammation in cancer cachexia, a syndrome worsening the prognosis of cancer patients. As the gut microbiota impinges on host metabolism through bile acids, the current study aimed to explore the functional contribution of gut microbial dysbiosis to bile acid dysmetabolism and associated disorders in cancer cachexia. Using three mouse models of cancer cachexia (the C26, MC38 and HCT116 models), we evidenced a reduction in the hepatic levels of several secondary bile acids, mainly taurodeoxycholic (TDCA). This reduction in hepatic TDCA occurred before the appearance of cachexia. Longitudinal analysis of the gut microbiota pinpointed an ASV, identified as Xylanibacter rodentium, as a bacterium potentially involved in the reduced production of TDCA. Coherently, stable isotope-based experiments highlighted a robust decrease in the microbial 7α-dehydroxylation (7α-DH) activity with no changes in the bile salt hydrolase (BSH) activity in cachectic mice. This approach also highlighted a reduced microbial 7α-hydroxysteroid dehydrogenase (7α-HSDH) and 12α-hydroxysteroid dehydrogenase (12α-HSDH) activities in these mice. The contribution of the lower production of TDCA to cancer cachexia was explored in vitro and in vivo. In vitro, TDCA prevented myotube atrophy, whereas in vivo hepatic whole transcriptome analysis revealed that TDCA administration to cachectic mice improved the unfolded protein response and cholesterol homeostasis pathways. Coherently, TDCA administration reversed hepatic cholesterol accumulation in these mice. Altogether, this work highlights the contribution of the gut microbiota to bile acid dysmetabolism and the therapeutic interest of the secondary bile acid TDCA for hepatic cholesterol homeostasis in the context of cancer cachexia. Such discovery may prove instrumental in the understanding of other metabolic diseases characterized by microbial dysbiosis. More broadly, our work demonstrates the interest and relevance of microbial activity measurements using stable isotopes, an approach currently underused in the microbiome field.

Expanding the immune-related targetome of miR-155-5p by integrating time-resolved RNA patterns into miRNA target prediction

The lack of a sufficient number of validated miRNA targets severely hampers the understanding of their biological function. Even for the well-studied miR-155-5p, there are only 239 experimentally validated targets out of 42,554 predicted targets. For a more complete assessment of the immune-related miR-155 targetome, we used an inverse correlation of time-resolved mRNA profiles and miR-155-5p expression of early CD4+ T cell activation to predict immune-related target genes. Using a high-throughput miRNA interaction reporter (HiTmIR) assay we examined 90 target genes and confirmed 80 genes as direct targets of miR-155-5p. Our study increases the current number of verified miR-155-5p targets approximately threefold and exemplifies a method for verifying miRNA targetomes as a prerequisite for the analysis of miRNA-regulated cellular networks.

Perinuclear organelle trauma at the nexus of cardiomyopathy pathogenesis arising from loss of function LMNA mutation

Over the past 25 years, nuclear envelope (NE) perturbations have been reported in various experimental models with mutations in the LMNA gene. Although the hypothesis that NE perturbations from LMNA mutations are a fundamental feature of striated muscle damage has garnered wide acceptance, the molecular sequalae provoked by the NE damage and how they underlie disease pathogenesis such as cardiomyopathy (LMNA cardiomyopathy) remain poorly understood. We recently shed light on one such consequence, by employing a cardiomyocyte-specific Lmna deletion in vivo in the adult heart. We observed extensive NE perturbations prior to cardiac function deterioration with collateral damage in the perinuclear space. The Golgi is particularly affected, leading to cytoprotective stress responses that are likely disrupted by the progressive deterioration of the Golgi itself. In this review, we discuss the etiology of LMNA cardiomyopathy with perinuclear 'organelle trauma' as the nexus between NE damage and disease pathogenesis.

Single-cell RNA sequencing reveals the heterogeneity and interactions of immune cells and Müller glia during zebrafish retina regeneration

JOURNAL/nrgr/04.03/01300535-202512000-00031/figure1/v/2025-01-31T122243Z/r/image-tiff Inflammation plays a crucial role in the regeneration of fish and avian retinas. However, how inflammation regulates Müller glia (MG) reprogramming remains unclear. Here, we used single-cell RNA sequencing to investigate the cell heterogeneity and interactions of MG and immune cells in the regenerating zebrafish retina. We first showed that two types of quiescent MG (resting MG1 and MG2) reside in the uninjured retina. Following retinal injury, resting MG1 transitioned into an activated state expressing known reprogramming genes, while resting MG2 gave rise to rod progenitors. We further showed that retinal microglia can be categorized into three subtypes (microglia-1, microglia-2, and proliferative) and pseudotime analysis demonstrated dynamic changes in microglial status following retinal injury. Analysis of cell-cell interactions indicated extensive crosstalk between immune cells and MG, with many interactions shared among different immune cell types. Finally, we showed that inflammation activated Jak1-Stat3 signaling in MG, promoting their transition from a resting to an activated state. Our study reveals the cell heterogeneity and crosstalk of immune cells and MG in zebrafish retinal repair, and may provide valuable insights into future mammalian retina regeneration.

Impact of liquid-liquid phase separation- and immune-related gene signatures on multiple myeloma prognosis: focus on DDX21 and EZH2

OBJECTIVE

Liquid-liquid phase separation (LLPS) may affect the therapeutic sensitivity of multiple myeloma (MM). This study aimed to identify LLPS-related genes with MM prognostic values and to confirm their effects on tumor progression.

METHODS

Based on public transcriptomic data, this study screened LLPS- and immune-related genes for MM-derived plasma cells. Subtypes were identified using consensus clustering, followed by comparisons using t-test and survival analysis. Least absolute shrinkage and selection operator was implemented to screen prognostic signatures, and Kaplan-Meier and receiver operator characteristic curves were plotted to assess their prognostic values. After transfected with sh-DDX21, CCK8, flow cytometry, and Transwells were used to observe MM cell proliferation, apoptosis, migration, and invasion.

RESULTS

By overlapping LLPS- and immune-related genes, 103 genes were obtained to cluster MM samples into three subtypes, which had significant differences in survival and immune landscape. Cox regression analysis screened out EZH2 and DDX21 that significantly overexpressed in MM to construct a prognostic model, with superior performance in predicting MM prognostic risks. Notably, subtype2 with more adverse prognosis showed significantly elevated risk scores and was more distributed in groups with high prognostic risk. In vitro experiments confirmed that cell proliferation, invasion, and migration were significantly inhibited in MM.1S cells transfected with sh-DDX21.

CONCLUSION

LLPS-related EZH2 and DDX21 were novel markers to predict prognostic risk of MM. Among them, DDX21 was experimentally confirmed to promote MM cell proliferation, migration and invasion. These potential prognostic markers could be targeted in future personalized therapeutic strategies for MM, potentially improving patient outcomes.

Exclusive breastfeeding is associated with the gut microbiome maturation in infants according to delivery mode

Exclusive breastfeeding (EBF) plays a crucial role in infant gut microbiome assembly and development. However, few studies have investigated the effects of EBF in restoring a perturbed microbiome. In this study, we applied whole metagenomic sequencing to assess the gut microbiome assembly in 525 Brazilian infants from 3 to 9 months of age of the Germina Cohort, demonstrating the early determinants of microbial taxonomy and function modulation. Our analysis shows that EBF alters the relative abundance of genes related to the microbiome taxonomy and function, with effects varying by delivery mode. EBF alters the pattern of carbohydrates, lipid metabolism, and cell structure pathways depending on the delivery mode. The microbiome age is closer to chronological infant age in EBF than in non-EBF infants, meaning a lower microbiome maturation index (MMI). Using a complementary machine learning approach, we show that Escherichia coli, Ruminococcus gnavus, and Clostridium neonatale, as well as vitamin K and o-antigen pathways contribute strongly to EBF prediction. Moreover, EBF influences the microbiome maturation in early life, toward a microbiome age more similar to the chronological infant's age.

Global research trends on biomarkers for cancer immunotherapy: Visualization and bibliometric analysis

The global burden of cancer continues to grow, posing a significant public health challenge. Although cancer immunotherapy has shown significant efficacy, the response rate is not high. Therefore, the objective of our research was to identify the latest research trends and hotspots on biomarkers from 1993 to 2023. Data were collected from the database Web of Science core collection. Bibliometric analysis and visualization were conducted with CiteSpace(6.3.1), VOSviewer (v1.6.20), R-bibliometrix(v4.3.3), and Microsoft Excel(2019). A total of 2686 literatures were retrieved. The sheer annual volume of publications has shown a rapid upward trend since 2015. The United States has generated the most publications and Harvard University ranked as a leading institution. The global biomarker research on immune checkpoint inhibitors (ICIs) revealed regional differences and in-depth explorations should be promoted in developing countries. Although China has become the second largest country in terms of publication, the average citation per paper and the total link strength were both lower than the other countries. The research on biomarkers mainly concentrated upon the following aspects: PD-1/PD-L1, CTLA-4, gene expression, adverse events, total mutational burden (TMB), body mass index (BMI), gut microbiota, cd8(+)/cd4(+) t-cells, and blood-related biomarkers such as lactate dehydrogenase (LDH), neutrophil-lymphocyte ratio (NLR), cytokines. Furthermore, "artificial intelligence" and "machine learning" have become the most important research hotspot over the last 2 y, which will help us to identify useful biomarkers from complex big data and provide a basis for precise medicine for malignant tumors.

Gut-derived lactic acid enhances tryptophan to 5-hydroxytryptamine in regulation of anxiety via Akkermansia muciniphila

The gut microbiota plays a pivotal role in anxiety regulation through pathways involving neurotransmitter production, immune signaling, and metabolic interactions. Among these, gut-derived serotonin (5-hydroxytryptamine, 5-HT), synthesized from tryptophan metabolism, has been identified as a key mediator. However, it remains unclear whether specific microbial factors regulate tryptophan metabolism to influence 5-HT production and anxiety regulation. In this study, we analyzed 110 athletes undergoing closed training and found that fecal lactate levels were significantly associated with anxiety indicators. We observed a significant negative correlation between Akkermansia abundance and anxiety levels in athletes. Co-supplementation with lactate and Akkermansia muciniphila (A. muciniphila) modulated tryptophan metabolism by increasing key enzyme TPH1 and reducing IDO1, thus shifting metabolism from kynurenine (Kyn) to 5-HT. In addition, lactate enhanced the propionate production capacity of A. muciniphila, potentially contributing to anxiety reduction in mice. Taken together, these findings suggest that enteric lactate and A. muciniphila collaboratively restore the imbalance in tryptophan metabolism, leading to increased 5-HT activity and alleviating anxiety phenotypes. This study highlights the intricate interplay between gut metabolites and anxiety regulation, offering potential avenues for microbiota-targeted therapeutic strategies for anxiety.

Anti-fibrosis effect of astragaloside IV in animal models of cardiovascular diseases and its mechanisms: a systematic review

CONTEXT

Myocardial fibrosis is a common manifestation of end-stage cardiovascular disease, but there is a lack of means to reverse fibrosis. Astragaloside IV (AS-IV), the major active component of Astragalus membranaceus Fisch. ex Bunge Fabaceae, possesses diverse biological activities that have beneficial effects against cardiovascular disease.

OBJECTIVE

This systematic review aims to summarize the anti-fibrosis effect of AS-IV in animal models (rats or mice only) and its underlying mechanisms, and provide potential directions for the clinical use of AS-IV.

METHODS

PubMed, EMBASE, Web of Science, CNKI, Wanfang database, and SinoMed were searched from inception to 31 December 2024. The following characteristics of the included studies were extracted and summarized: animal model, route of administration, dose/concentration, measurement indicators, and potential mechanisms. The quality of the included studies was assessed used a 10-item scale from SYRCLE.

RESULTS AND CONCLUSION

AS-IV represents a promising multi-target candidate for myocardial fibrosis treatment in the 24 eligible studies included in the analysis. This systematic review is the first to comprehensively evaluate the anti-fibrosis mechanisms of AS-IV across heterogeneous cardiovascular disease animal models, including myocardial infarction, hypertension, ischemia-reperfusion injury, and myocarditis. The underlying mechanisms of the anti-fibrosis effects of AS-IV may include collagen metabolism, anti-apoptosis, anti-inflammation and, pyroptosis, antioxidants, improving mitochondrial function, regulating senescence, etc. Current evidence remains preclinical, with critical gaps in toxicological profiles, human safety thresholds, and clinical adverse reaction data. Future research must integrate robust toxicological evaluations, optimized combination therapies, and adaptive clinical trials to validate translational potential.

Acetaldehyde-driven mRNA methylation and expression changes in ethanol-metabolizing enzyme genes

This study examines how the alcohol metabolite acetaldehyde modulates mRNA methylation and expression of ethanol-metabolizing genes, uncovering its epigenetic role in ethanol metabolism. Using neuron-like (SH-SY5Y) and non-neuronal (SW620) cellular models, we examined the effects of chronic intermittent acetaldehyde (CIA) exposure and subsequent withdrawal (CIA+WD) on global RNA m6A modifications and the methylation and expression of three brain ethanol-metabolizing genes: CAT (catalase), CYP2E1 (cytochrome P450 2E1), and ALDH2 (aldehyde dehydrogenase 2). A 3-week CIA exposure, with or without 24-hour withdrawal, did not significantly alter global m6A methylation levels in either cell line. However, acetaldehyde exposure/withdrawal induced hypermethylation at the mRNA stop codon regions of ALDH2 (CIA: p = 0.002; CIA+WD: p = 0.055) and CAT (CIA: p = 0.077; CIA+WD: p = 0.036) in SH-SY5Y cells, but not in SW620 cells. Furthermore, ALDH2 mRNA expression was significantly upregulated in both cell types following exposure (SH-SY5Y: p = 0.073 [CIA] and 0.00002 [CIA+WD]; SW620: p = 0.0009 [CIA] and 0.00008 [CIA+WD]). In contrast, CYP2E1 mRNA methylation and the expression of CYP2E1 and CAT remained unchanged. These findings highlight the cell-specific epigenetic effects of acetaldehyde, particularly its role in modulating mRNA methylation and expression of ALDH2, a key enzyme in alcohol metabolism.

Calpain 2 regulates IL-1α secretion and inhibits tumor development via modulating calpain 1 expression in the tumor microenvironment

Tumor-promoting inflammation significantly impacts cancer progression, and targeting inflammatory cytokines has emerged as a promising therapeutic approach in clinical trials. Interleukin (IL)-1α, a member of the IL-1 cytokine family, plays a crucial role in both inflammation and carcinogenesis. How IL-1α is secreted in the tumor microenvironment has been poorly understood, and we previously showed that calpain 1 cleaves pro-IL-1α for mature IL-1α secretion, which exacerbates hepatocellular carcinoma by recruiting myeloid-derived suppressor cells. In this study, we report that calpain 2 also modulates IL-1α secretion. Notably, a deficiency in calpain 2 resulted in enhanced hepatocellular carcinoma development within an IL-1α-enriched tumor microenvironment. Further investigations revealed that calpain 2 deficiency increased calpain 1 expression, implying a compensatory mechanism between the two calpains. Mechanistically, calpain 2 deficiency led to increased expression of FoxO3, which is a forkhead transcription factor that promotes calpain 1 expression. Collectively, these results suggest that calpain 2 modulates calpain 1 expression, and therefore IL-1α secretion through the induction of FoxO3, offering novel potential therapeutic targets for cancer treatment.

The role and function of lncRNA in ageing-associated liver diseases

Liver diseases are a significant global health issue, characterized by elevated levels of disorder and death. The substantial impact of ageing on liver diseases and their prognosis is evident. Multiple processes are involved in the ageing process, which ultimately leads to functional deterioration of this organ. The process of liver ageing not only renders the liver more susceptible to diseases but also compromises the integrity of other organs due to the liver's critical function in metabolism regulation. A growing body of research suggests that long non-coding RNAs (lncRNAs) play a significant role in the majority of pathophysiological pathways. They regulate gene expression through a variety of interactions with microRNAs (miRNAs), messenger RNAs (mRNAs), DNA, or proteins. LncRNAs exert a major influence on the progression of age-related liver diseases through the regulation of cell proliferation, necrosis, apoptosis, senescence, and metabolic reprogramming. A concise overview of the current understanding of lncRNAs and their potential impact on the development of age-related liver diseases will be provided in this mini-review.

With great power, comes great responsibility: the importance of broadly measuring Fc-mediated effector function early in the antibody development process

The field of antibody therapeutics is rapidly growing, with over 210 antibodies currently approved or in regulatory review and ~ 1,250 antibodies in clinical development. Antibodies are highly versatile molecules that, with strategic design of their antigen-binding domain (Fab) and the domain responsible for mediating effector functions (Fc), can be used in a wide range of therapeutic indications. Building on many years of progress, the biopharmaceutical industry is now advancing innovative research and development by exploring new targets and new formats and using antibody engineering to fine-tune functions tailored to specific disease requirements. In addition to considering the target and the disease context, however, the unique features of each therapeutic antibody trigger a diverse set of Fc-mediated effector functions. To avoid unexpected results on safety and efficacy outcomes during the later stages of the development process, it is crucial to measure the impact of antibody design on Fc-mediated effector function early in the antibody development process. Given the breadth of effector functions antibodies can deploy and the close interplay between the antibody Fab and Fc functional domains, it is important to conduct a comprehensive evaluation of Fc-mediated functions using an array of antigen-specific biophysical and cell-mediated functional assays. Here, we review antibody and Fc receptor properties that influence Fc effector functions and discuss their implications on development of safe and efficacious antibody therapeutics.

Restriction of mitochondrial oxidation of glutamine or fatty acids enhances intracellular growth of Mycobacterium abscessus in macrophages

Mycobacterium abscessus (Mab), a nontuberculous mycobacterium, is increasing in prevalence worldwide and causes treatment-refractory pulmonary diseases. However, how Mab rewires macrophage energy metabolism to facilitate its survival is poorly understood. We compared the metabolic profiles of murine bone marrow-derived macrophages (BMDMs) infected with smooth (S)- and rough (R)-type Mab using extracellular flux technology. Mab infection shifted BMDMs towards a more energetic phenotype, marked by increased oxidative phosphorylation (OXPHOS) and glycolysis, with a significantly greater enhancement in OXPHOS. This metabolic adaptation was characterized by enhanced ATP production rates, particularly in cells infected with S-type Mab, highlighting OXPHOS as a key energy source. Notably, Mab infection also modulated mitochondrial substrate preferences, increasing fatty acid oxidation capabilities while revealing significant changes in glutamine dependency and flexibility. R-type Mab infections exhibited a marked decrease in glutamine reliance but enhanced metabolic flexibility and capacity. Furthermore, targeting metabolic pathways related to glutamine and fatty acid oxidation exacerbated Mab growth within macrophages, suggesting these pathways play a protective role against infection. These insights advance our understanding of Mab's impact on host cell metabolism and propose a novel avenue for therapeutic intervention. By manipulating host mitochondrial metabolism, we identify a potential host-directed therapeutic strategy against Mab, offering a promising alternative to conventional treatments beleaguered by drug resistance. This study underscores the importance of exploring metabolic interventions to combat Mab infection, paving the way for innovative approaches in the fight against this formidable pathogen.