CC chemokines family in fibrosis and aging: From mechanisms to therapy

Scientific status analysis of exercise benefits for vascular cognitive impairment: Evidence of neuroinflammation

Vascular cognitive impairment (VCI) is a syndrome characterized by cognitive decline resulting from insufficient perfusion to the entire brain or specific brain regions. The lack of a clear understanding of the mechanisms linking cerebrovascular disease to cognitive impairment has impeded the development of targeted treatments for VCI. Increasing evidence indicates that exercise may offer significant benefits for patients with VCI. This study explores how neuroinflammatory mechanisms mediate the effects of exercise on VCI, focusing on the broader biological processes involved. Exercise plays a crucial role in mitigating vascular risk factors, reducing oxidative stress, and promoting neurogenesis. Furthermore, exercise influences neuroinflammatory mediators and central immune cells via various signaling pathways. Different types and intensities of exercise, including resistance and endurance training, have been shown to differentially modulate neuroinflammation during the progression of VCI. This paper summarizes the current mechanisms of action and proposes exercise interventions targeting neuroinflammatory pathways, along with biomarker studies, to enhance our understanding of VCI pathogenesis and inform clinical practice. A more in-depth understanding of the inflammatory mechanisms underlying VCI may facilitate the development of targeted therapeutic interventions.

Orchestration of immunoregulatory signaling ligand and receptor dynamics by mRNA modifications: Implications for therapeutic potential

RNA modifications are pivotal regulators of gene expression, significantly influencing immune responses by modulating the stability and translation of mRNAs encoding key immunoregulatory ligands and receptors. Among these modifications, N6-methyladenosine (m6A) is the most abundant and well-characterized, orchestrating immune evasion, T-cell exhaustion, and cytokine production by dynamically regulating transcripts such as PD-L1, IFN-γ, and TGF-β. These modifications critically impact the function and availability of proteins essential for maintaining immune homeostasis and shaping adaptive immune responses. This review comprehensively examines established and emerging roles of mRNA modifications in regulating immunoregulatory signaling, including co-inhibitory and co-stimulatory molecules, chemokines, cytokines, and transforming growth factor-β. We highlight how m6A writers, erasers, and readers finely regulate immune checkpoints and inflammatory pathways across cancer, infection, and autoimmune diseases. Furthermore, the review provides a critical analysis of current discrepancies in the field, emphasizing factors contributing to inconsistencies and offering insights into the complex nature of epigenetic regulation. Challenges and limitations in this rapidly evolving area are also discussed. Advancing detection technologies and developing specific inhibitors targeting RNA-modifying proteins will be crucial for precisely modulating immune responses, paving the way for innovations in precision medicine and immunotherapy.

Sensor-integrated gut-on-a-chip for monitoring senescence-mediated changes in the intestinal barrier

The incidence of inflammatory bowel disease among the elderly has significantly risen in recent years, posing a growing socioeconomic burden to aging societies. Moreover, non-gastrointestinal diseases, also prevalent in this demographic, have been linked to intestinal barrier dysfunction, thus highlighting the importance of investigating aged-mediated changes within the human gut. While gastrointestinal pathology often involves an impaired gut barrier, the impact of aging on the human gastrointestinal barrier function remains unclear. To explore the effect of senescence, a key hallmark of aging, on gut barrier integrity, we established and evaluated an in vitro gut-on-a-chip model tailored to investigate barrier changes by the integration of an impedance sensor. Here, a microfluidic gut-on-a-chip system containing integrated membrane-based electrode microarrays is used to non-invasively monitor epithelial barrier formation and senescence-mediated changes in barrier integrity upon treating Caco-2 cells with 0.8 μg mL-1 doxorubicin (DXR), a chemotherapeutic which induces cell cycle arrest. Results of our microfluidic human gut model reveal a DXR-mediated increase in impedance and cell hypertrophy as well as overexpression of p21, and CCL2, indicative of a senescent phenotype. Combined with the integrated electrodes, monitoring ∼57% of the cultivation area in situ and non-invasively, the developed chip-based senescent-gut model is ideally suited to study age-related malfunctions in barrier integrity.

Midkine, a novel MCP-1 activator mediated PM2.5-aggravated experimental pulmonary fibrosis

Exposure to fine particulate matter (PM2.5) is associated with increased morbidity and mortality among patients with idiopathic pulmonary fibrosis (IPF). Pathological alterations in IPF typically originate in the subpleural regions of the lungs. However, it was unclear how PM2.5 affected subpleural pulmonary fibrosis. In this study, atmospheric PM2.5 and carbon blacks were utilized as representative particulate matter to investigate these effects. Mouse models and cell models were made to investigate macrophage chemotaxis changes under PM2.5 exposure in vivo and in vitro. The findings indicated that PM2.5 promoted macrophage aggregation in the subpleural region of lung and aggravated bleomycin-induced pulmonary fibrosis in mice. At the same time, we uncovered for the first time that PM2.5 exposure led to an upregulation of midkine, which subsequently enhanced the production of monocyte chemotactic protein-1 (MCP-1) through the cell surface receptor Syndecan 4 (SDC4) in pleural mesothelial cells (PMCs), thereby, inducing macrophage aggregation in subpleural region of lung. Furthermore, our results indicated that PM2.5 and bleomycin facilitated macrophage M1 polarization and the production of profibrotic inflammatory factors, culminating in fibrotic alterations in PMCs, lung fibroblasts, and alveolar epithelial cells. Finally, we demonstrated that inhibition of midkine ameliorated lung function and mitigated pulmonary fibrosis in vivo. In conclusion, our findings elucidated that midkine acted as a novel MCP-1 activator, mediating PM2.5-aggravated experimental pulmonary fibrosis, and suggested that the midkine/SDC4/MCP-1 signal should be a new therapeutic target for the treatment of PM2.5-related IPF.

Combined treatment of Ketogenic diet and propagermanium reduces neuroinflammation in Tay-Sachs disease mouse model

Tay-Sachs disease is a rare lysosomal storage disorder caused by β-Hexosaminidase A enzyme deficiency causing abnormal GM2 ganglioside accumulation in the central nervous system. GM2 accumulation triggers chronic neuroinflammation due to neurodegeneration-based astrogliosis and macrophage activity with the increased expression level of Ccl2 in the cortex of a recently generated Tay-Sachs disease mouse model Hexa-/-Neu3-/-. Propagermanium blocks the neuroinflammatory response induced by Ccl2, which is highly expressed in astrocytes and microglia. The ketogenic diet has broad potential usage in neurological disorders, but the knowledge of the impact on Tay-Sach disease is limited. This study aimed to display the effect of combining the ketogenic diet and propagermanium treatment on chronic neuroinflammation in the Tay-Sachs disease mouse model. Hexa-/-Neu3-/- mice were placed into the following groups: (i) standard diet, (ii) ketogenic diet, (iii) standard diet with propagermanium, and (iv) ketogenic diet with propagermanium. RT-PCR and immunohistochemistry analyzed neuroinflammation markers. Behavioral analyses were also applied to assess phenotypic improvement. Notably, the expression levels of neuroinflammation-related genes were reduced in the cortex of 140-day-old Hexa-/-Neu3-/- mice compared to β-Hexosaminidase A deficient mice (Hexa-/-) after combined treatment. Immunohistochemical analysis displayed correlated results with the RT-PCR. Our data suggest the potential to implement combined treatment to reduce chronic inflammation in Tay-Sachs and other lysosomal storage diseases.

Role of chemokines in aging and age-related diseases

Chemokines (chemotactic cytokines) play essential roles in developmental process, immune cell trafficking, inflammation, immunity, angiogenesis, cellular homeostasis, aging, neurodegeneration, and tumorigenesis. Chemokines also modulate response to immunotherapy, and consequently influence the therapeutic outcome. The mechanisms underlying these processes are accomplished by interaction of chemokines with their cognate cell surface G protein-coupled receptors (GPCRs) and subsequent cellular signaling pathways. Chemokines play crucial role in influencing aging process and age-related diseases across various tissues and organs, primarily through inflammatory responses (inflammaging), recruitment of macrophages, and orchestrated trafficking of other immune cells. Chemokines are categorized in four distinct groups based on the position and number of the N-terminal cysteine residues; namely, the CC, CXC, CX3C, and (X)C. They mediate inflammatory responses, and thereby considerably impact aging process across multiple organ-systems. Therefore, understanding the underlying mechanisms mediated by chemokines may be of crucial importance in delaying and/or modulating the aging process and preventing age-related diseases. In this review, we highlight recent progress accomplished towards understanding the role of chemokines and their cellular signaling pathways involved in aging and age-relaed diseases of various organs. Moreover, we explore potential therapeutic strategies involving anti-chemokines and chemokine receptor antagonists aimed at reducing aging and mitigating age-related diseases. One of the modern methods in this direction involves use of chemokine receptor antagonists and anti-chemokines, which suppress the pro-inflammatory response, thereby helping in resolution of inflammation. Considering the wide-spectrum of functional involvements of chemokines in aging and associated diseases, several clinical trials are being conducted to develop therapeutic approaches using anti-chemokine and chemokine receptor antagonists to improve life span and promote healthy aging.

Pathological and Molecular Characterization of Grass Carp Co-Infected with Two Aeromonas Species

The grass carp (Ctenopharyngodon idella) is highly susceptible to infections caused by Aeromonas species, particularly A. hydrophila and A. veronii. However, the immunological mechanisms underlying co-infection by these pathogens remain largely uncharted. This study investigated the pathogenesis and host immune response in grass carp following concurrent infection with A. hydrophila and A. veronii. Mortality was observed as early as 24 h post-infection, with cumulative mortality reaching 68%. Quantitative analysis demonstrated significantly elevated bacterial loads in hepatic tissue at 3 days post-infection (dpi). Histopathological evaluation revealed severe hepatic lesions characterized by cellular necrosis, cytoplasmic vacuolization, and hemorrhagic manifestations. Comparative transcriptomic analysis of hepatic tissues between co-infected and control specimens identified 868 and 411 differentially expressed genes (DEGs) at 1 and 5 dpi, respectively. Gene ontology and KEGG pathway analyses revealed significant enrichment of immune-related genes primarily associated with Toll-like receptor signaling and TNF signaling cascades. Notably, metabolic pathways showed substantial suppression while immune responses were significantly activated after infected. These findings provide novel insights into the host-pathogen interactions during Aeromonas co-infection in grass carp, which may facilitate the development of effective prevention and control strategies.

Identification and Validation of Epithelial Cell Centre Regulatory Transcription Factors in the Gastric Cancer Microenvironment

Purpose

To identify the epithelial cell centre regulatory transcription factors in the gastric cancer (GC) microenvironment and provide a new strategy for the diagnosis and treatment of GC.

Methods

The GC single-cell dataset was downloaded from the Gene Expression Omnibus (GEO) database. The regulatory mechanisms of transcription factors in both pan-cancer and GC microenvironments were analysed using the Cancer Genome Atlas (TGCA) database. Real-time quantitative PCR (RT-qPCR) was used to determine the mRNA expression levels of Prospero homeobox gene 1 (PROX1) and Endothelial PAS domain-containing protein 1 (EPAS1) in the human gastric mucosal normal epithelial cell line (GES-1) and the GC cell line (AGS). Immunohistochemistry (IHC) was used to determine the amounts of PROX1 and EPAS1 protein expression in GC and adjacent tissues. GC patients' overall survival (OS) was tracked through outpatient, Inpatient case inquiry, or phone follow-up.

Results

The single-cell data from GSE184198 was re-annotated, resulting in nine cell subsets: T cells (13364), NK cells (606), B cells (2525), Epithelial cells (2497), DC cells (1167), Fibroblast cells (372), Endothelial cells (271), Neutrophils cells (246) and Macrophage cells (420). Analysis of cell subgroup signalling pathways revealed that communication intensity between epithelial cells and smooth muscle cells was highest. Transcription factors PROX1 and EPAS1 were notably active in epithelial cells. Cell communication analysis indicated that IFNG may interact with IFNGR1/2 and LIF with IL6ST and LIFR to regulate the downstream PROX1 and EPAS1. PROX1 and EPAS1 were upregulated and negatively correlated with tumour mutation burden (TMB). They also exhibited high positive correlations with immune checkpoints CTLA4 and PDCD1LG2, as well as with chemokines CCL24 and CXCL12 and their receptors CCR3 and CCR4. Additionally, PROX1 and EPAS1 were positively correlated with immunosuppressive factors ADORA2A, CD160, IL10, TGFBR1, KDR and CSF1R, as well as with immunostimulators CD276, PVR, TNFRSF25, ULBP1, CXCL12 and ENTPD1. In GC tissues and AGS, PROX1 and EPAS1 were both substantially expressed. In the meantime, they showed a positive correlation with clinicopathological features such TNM stage and degree of differentiation. In GC patients, the up-regulated group's PROX1 and EPAS1 prognosis was noticeably poorer than the down-regulated group's.

Conclusion

PROX1 and EPAS1 are likely central regulatory transcription factors in the epithelial cells of the GC environment, regulated by IFNG and LIF. They may contribute to GC progression by modulating the tumour's immune microenvironment.

Transcriptome analyses reveal key features of mouse seminal vesicle during aging

Despite the significant morphological changes that occur in the seminal vesicles with aging, the transcriptomic characteristics remain largely unexplored. To address this, we performed bulk RNA sequencing on seminal vesicle samples from mice aged 3, 13, and 21 months to uncover transcriptomic alterations. Our findings reveal that aged seminal vesicles display cystic dilatation, epithelial hypoplasia, disordered muscle layers, fibrosis, and reduced proliferation capability. A comparison between 3-month-old and 21-month-old mice indicated that leukocyte-mediated immunity and leukocyte migration were the most significantly upregulated biological processes among differentially expressed genes (DEGs). Notably, several DEGs associated with "leukocyte migration," such as Vcam1, Cxcl13, and Ccl8, exhibited an increasing trend in transcriptomic and protein expression at three different time points in the seminal vesicles of mice. Additionally, we identified multiple aging-associated DEGs, including P21 and Tnfrsf1b. Two genes (Cd209f and Ccl8) were consistently upregulated across all six regions of the male reproductive glands (testis, epididymis, and seminal vesicle) in the comparison of bulk RNA datasets from 3-month-old and 21-month-old mice. These analyses highlight an enhanced state of immune and inflammatory response in aged seminal vesicles. This study represents the first exploration of the overall transcriptome landscape of seminal vesicles in a murine model of natural aging, offering new insights into the mechanisms underlying aging-related seminal vesicle dysfunction.

CX3C chemokine: Hallmarks of fibrosis and ageing

Fibrosis refers to the progressive tissue lesion process characterized by excessive secretion and deposition of extracellular matrix (ECM). Abnormal fibrous tissue deposition distorts tissue architecture and leads to the progressive loss of organ function. Notably, fibrosis is one of the primary pathological appearances of many end stage illnesses, and is considered as a lethal threat to human health, especially in the elderly with ageing-related diseases. CX3C ligand 1 (CX3CL1) is the only member of chemokine CX3C and binds specifically to CX3C receptor 1 (CX3CR1). Different from other chemokines, CX3CL1 possesses both chemotactic and adhesive activity. CX3CL1/CX3CR1 axis involves in various physiological and pathological processes, and exerts a critical role in cells from the immune system, vascular system, and nervous system etc. Notably, increasing evidence has demonstrated that CX3CL1/CX3CR1 signaling pathway is closely related to the pathological process of fibrosis in multiple tissue and organs. We reviewed the crucial role of CX3CL1/CX3CR1 axis in fibrosis and ageing and systematically summarized the underlying mechanism, which offers prospective strategies of targeting CX3C for the therapy of fibrosis and ageing-related diseases.

The Impact of Liver Failure on the Immune System

Liver failure profoundly affects the immune system, leading to dysregulation of innate and adaptive immune response. This review explores the intricate relationship between liver function and immune homeostasis. The role of the liver as a central hub in immune response initiation is elucidated, emphasizing its involvement in hepatic inflammation induction and subsequent systemic inflammation. Cytokines, chemokines, growth factors, and lipid mediators orchestrate these immune processes, serving as both prognostic biomarkers and potential therapeutic targets in liver failure-associated immune dysregulation, which might result from acute-on-chronic liver failure (ACLF) and cirrhosis. Furthermore, the review delves into the mechanisms underlying immunosuppression in liver failure, encompassing alterations in innate immune cell functions such as neutrophils, macrophages, and natural killer cells (NK cells), as well as perturbations in adaptive immune responses mediated by B and T cells. Conclusion: Understanding the immunological consequences of liver failure is crucial for developing targeted therapeutic interventions and improving patient outcomes in liver disease management.

Integrated time-series biochemical, transcriptomic, and metabolomic analyses reveal key metabolites and signaling pathways in the liver of the Chinese soft-shelled turtle (Pelodiscus sinensis) against Aeromonas hydrophila infection

Introduction

Aeromonas hydrophila, a bacterium widely distributed in the natural environment, causes multiple diseases in various animals. Exploring the mechanism of the host defense against A. hydrophila can help develop efficient strategies against Aeromonas infection.

Methods

Herein, we investigated the temporal influence of A. hydrophila on the Chinese soft-shelled turtle, an economically important species, at the biochemical, transcriptomic, and metabolomic levels. Plasma parameters were detected with the test kits. Transcriptome and metabolome were respectively applied to screen the differentially expressed genes and metabolites.

Results

The contents or activities of these plasma parameters were significantly increased at 24 hpi and declined at 96 hpi, indicating that 24 and 96 hpi were two important time points during infection. Totals of 3121 and 274 differentially expressed genes (DEGs) from the transcriptome while 74 and 91 differentially abundant metabolites (DAMs) from the metabolome were detected at 24 and 96 hpi. The top DEGs at 24 hpi included Ccl2, Ccl3, Ccl4, Il1β, Il6, Il7, Il15, Tnf, and Tnfr1 while Zap70, Cd3g, Cd8a, Itk, Pik3r3, Cd247, Malt1, and Cd4 were the most abundant at 96 hpi. The predominant DAMs included O-phospho-L-serine, γ-Aminobutyric acid, orotate, L-tyrosine, and L-tryptophan at 24 hpi, as well as L-glutamic acid, L-arginine, glutathione, glutathione disulfide, and citric acid at 96 hpi.

Discussion

The combined analysis of DEGs and DAMs revealed that tryptophan metabolism, nicotinate and nicotinamide metabolism, as well as starch and sucrose metabolism, were the most important signaling pathways at the early infective stage while tyrosine metabolism, pyrimidine metabolism, as well as alanine, aspartate and glutamate metabolism were the most crucial pathways at the later stage. In general, our results indicated that the Chinese soft-shelled turtle displays stage-specific physiological responses to resist A. hydrophila infection.

Harnessing anti-inflammatory pathways and macrophage nano delivery to treat inflammatory and fibrotic disorders

Targeting specific organs and cell types using nanotechnology and sophisticated delivery methods has been at the forefront of applicative biomedical sciences lately. Macrophages are an appealing target for immunomodulation by nanodelivery as they are heavily involved in various aspects of many diseases and are highly plastic in their nature. Their continuum of functional "polarization" states has been a research focus for many years yielding a profound understanding of various aspects of these cells. The ability of monocyte-derived macrophages to metamorphose from pro-inflammatory to reparative and consequently to pro-resolving effectors has raised significant interest in its therapeutic potential. Here, we briefly survey macrophages' ontogeny and various polarization phenotypes, highlighting their function in the inflammation-resolution shift. We review their inducing mediators, signaling pathways, and biological programs with emphasis on the nucleic acid sensing-IFN-I axis. We also portray the polarization spectrum of macrophages and the characteristics of their transition between different subtypes. Finally, we highlighted different current drug delivery methods for targeting macrophages with emphasis on nanotargeting that might lead to breakthroughs in the treatment of wound healing, bone regeneration, autoimmune, and fibrotic diseases.