Journal of Biomedical Science最新文献

The microbiome has emerged as a critical, context-dependent regulator of tumorigenesis and anticancer immunity, capable of either promoting cancer progression or protecting against malignancy. This dual role is mediated by multiple interconnected mechanisms-including chronic inflammation, modulation of immune responses, and alterations in host metabolic signaling. These microbiome-cancer interactions vary across organs, influencing malignancies in the colon, breast, lung, and beyond. Clinically, the microbiome significantly affects patient responses to cancer therapies, particularly immunotherapies such as immune checkpoint blockade (ICB) and chimeric antigen receptor (CAR)-T cell therapy. Although emerging therapeutic strategies aimed at modulating the microbiome have shown promising early results, challenges remain, including individual microbiome variability and the dynamic interplay between the immune system and microbial communities. Nevertheless, harnessing the microbiome holds significant potential to transform precision oncology, offering personalized cancer prevention and treatment strategies tailored to each patient's unique microbial ecosystem.

Background: Recent research has revealed a strong connection between neuroinflammation and TAU protein-related neurodegeneration. A key discovery shows that the NLRP3 inflammasome, when activated, can significantly impact TAU pathology and subsequent neuronal death. This process involves pyroptosis, a lytic form of programmed cell death driven by inflammasome activation, leading to GASDERMIN D (GSDMD) cleavage and the subsequent release of inflammatory molecules IL-1β and IL-18. In this study, we explore the role of pyroptosis and GSDMD in Alzheimer's disease (AD) and tauopathy models, focusing on the TAU-induced neuroinflammatory process and its correlation with synaptic plasticity loss.

Methods: Hippocampal tissue from AD patients at Braak stage II-III has been analyzed using qPCR to assess pyroptosis-related gene expression. To determine the role of TAU in pyroptosis and neuroinflammation, we used two different models: one based on intracerebral injection of an adeno-associated virus that specifically overexpresses TAU in the neurons of the hippocampus (AAV-TAU^P301L), and a transgenic mouse model Tg-TAU^P301S at 8 and 10 months of age. Gene expression, protein levels, and neuroinflammation markers were evaluated using qPCR and immunofluorescence. Additionally, both genetic (GSDMD-deficient mice) and pharmacological (dimethyl fumarate, DMF) interventions targeting pyroptosis have been explored to assess their impact on neuroinflammation and synaptic plasticity.

Results: AD patients exhibited increased expression of pyroptosis-related genes, supporting the involvement of pyroptosis in neurodegeneration. Furthermore, TAU overexpression induced pyroptosis in both mouse models, and GSDMD protein levels increased alongside reactive microglial morphology. Our data supports that TAU-induced neuroinflammation correlated with synaptic plasticity impairment. GSDMD deficiency significantly reduced pyroptosis-related markers associated to TAU, but unexpectedly worsened synaptic plasticity deficits, suggesting GSDMD may play a dual role in inflammation and synaptic function. Finally, we showed that DMF treatment suppressed pyroptosis gene expression, reduced GSDMD levels, and alleviated neuroinflammation, correlating with improved synaptic marker expression.

Conclusion: Our findings demonstrate that TAU-induced pyroptosis contributes to neuroinflammation and synaptic dysfunction. While GSDMD inhibition mitigates inflammation, its absence exacerbates synaptic impairment, highlighting its complex role in tauopathies. Our results indicate that DMF treatment could offer a promising therapeutic avenue to modulate pyroptosis and neuroinflammation, and restore synaptic integrity in tauopathies.

Background: Lactobacillus crispatus is a dominant member of the healthy female reproductive tract microbiota, contributing to mucosal homeostasis and pathogen exclusion. Numerous studies have highlighted the protective effects of L. crispatus against both intestinal and genital infections. In the present study, we build on this foundation to investigate the broader health-promoting properties of L. crispatus, focusing on its antimicrobial and metabolic functions; and its protective roles in hepatic and cardiometabolic disorders.

Methods: Three L. crispatus strains were selected from a panel of sixty isolates based on comprehensive genome mining analyses described in our previous publication. In the present study, we generated complete genome data for these three strains, and delineated biosynthetic pathways including their capacity for antimicrobial peptide production, lactic acid biosynthesis, short chain fatty acid synthesis and biogenic amine production. The antimicrobial activity of these isolates was assessed via agar well-diffusion assay and time-kill assay. Their ability to survive gastric pH and bile stress was evaluated through acid and bile salt tolerance assays. Further, to assess metabolic benefits, anti-steatotic and cardioprotective effects were examined in a preclinical diet-induced mouse model of cardiometabolic disorder.

Results: Complete genome analysis of L. crispatus strains revealed multiple antimicrobial peptide (AMP) biosynthetic gene clusters, including several novel loci associated with bacteriocins. Metabolic profiling identified pathways for bile salt metabolism, folate biosynthesis and short chain fatty acids production. Cell-free culture supernatants exhibited broad-spectrum antibacterial activity, particularly against Escherichia coli, Enterobacter hormaechei, Staphylococcus aureus and Staphylococcus haemolyticus. Further, the strains tolerated gastric pH 2 and physiological bile stress of 0.3% suggesting potential for oral administration. In vivo, oral administration of L. crispatus (10⁸ CFU) daily for 2 weeks followed by twice-weekly for 12 weeks significantly reduced hepatic steatosis, improved insulin sensitivity and cardiac function in a diet-induced cardiometabolic disorder mouse model. This is the first report demonstrating the cardiometabolic protective potential of L. crispatus.

Conclusions: L. crispatus confers diverse health benefits through pathogen resistance functions and modulation of host metabolic pathways. These findings support its potential as a novel biotherapeutic for preventing and managing hepatic and cardiometabolic disorders, extending its therapeutic relevance beyond reproductive health.

Background: Mutations in the Immunoglobulin Mu DNA Binding Protein 2 (IGHMBP2) gene cause Spinal Muscular Atrophy with Respiratory Distress type 1 (SMARD1), a rare, infantile, and fatal motor neuron disease, as well as the milder Charcot-Marie-Tooth disease type 2S (CMT2S). Gene therapy has emerged as a promising approach to correcting IGHMBP2 loss in SMARD1 models, but critical challenges remain.

Methods: In this study, we compared the efficacy of two novel, optimized adeno-associated virus 9 (AAV9)-IGHMBP2 vectors, utilizing either the Chicken β-Actin (CBA) or a truncated form of the methyl-CpG-binding protein 2 (MeCP2) promoter (P546), in the SMARD1 murine model via intracerebroventricular delivery. Treated mice survival, histopathological and molecular profile were analyzed.

Results: Corroborating previous findings, both constructs effectively rescued the pathological phenotype, significantly improving survival, body weight, and motor function while preserving motor neurons and neuromuscular junctions. Notably, histopathological and RNA sequencing analyses revealed, for the first time, inflammatory marker alterations in the SMARD1 spinal cord, which resolved following treatment. A comparative analysis of the two vectors demonstrated superior long-term efficacy of the P546-promoter construct.

Conclusion: ICV gene therapy approach can effectively rescue SMARD1 pathological hallmarks, including astrogliosis and microgliosis. Moreover, P546-promoter construct is superior in terms of safety profile and long-term therapeutic efficacy.

Background: Radiation (RT)-promoted distant metastasis (DM) is an underrecognized complication that can compromise the therapeutic efficacy of local RT. This study aimed to identify tumor microenvironment (TME) traits that predispose to RT-promoted DM and provide mechanistic insights for potential therapeutic intervention.

Methods: We performed NanoString analysis on tumor samples from urothelial cancer patients to compare the TME profiles of those with and without RT-promoted DM. To complement clinical findings, we conducted RNA sequencing (RNAseq) of murine bladder cancer cell lines, MB49 (with RT-promoted DM) and MBT2 (without), followed by in vivo ectopic tumor modeling, flow cytometry of immune cell infiltrates, and cytokine array profiling.

Results: NanoString analysis revealed a significant enrichment of C-X-C motif receptor 2 (CXCR2)-expressing neutrophils in the TME of patients with RT-promoted DM. These tumors also exhibited nuclear factor kappa B (NFκB) activation and increased secretion of neutrophil-recruiting chemokines. RNAseq and cytokine profiling identified CD14 expression in tumor cells as a key upstream regulator of neutrophilic TME via NFκB signaling. The use of antagonists to block neutrophils and inhibit CD14 expression in cancer cells, which reduces the secretion of neutrophil-recruiting chemokines, effectively mitigated RT-promoted DM in both the MB49 and LLC mouse models.

Conclusions: CD14 expression in tumor cells plays a pivotal role in shaping a neutrophil-enriched TME, which increases the susceptibility to RT-promoted DM. CD14 represents a potential predictive biomarker and therapeutic target for mitigating this adverse outcome.

Immune checkpoints play pivotal roles in regulating immune responses and maintaining tolerance. In cancer, these molecules are hijacked to suppress antitumor immunity, resulting in therapeutic resistance to immune checkpoint blockade (ICB). Recent advances have highlighted the critical role of post-translational modifications (PTMs), including phosphorylation, ubiquitination, glycosylation, palmitoylation, UFMylation, acetylation, SUMOylation, methylation, and ISGylation, in modulating checkpoint stability, trafficking, and function across diverse immune and tumor cell types. These dynamic PTMs reshape the tumor microenvironment (TME) by controlling immune cell function, antigen presentation, and inflammatory signaling. This review comprehensively outlines the mechanistic contributions of PTMs to immune checkpoint regulation, emphasizing how these PTMs orchestrate immune evasion and clinical outcomes. Special focus is given to PTMs of PD-L1, PD-1, TIM-3, TIGIT, CTLA-4, LAG-3, VISTA, BTLA, and SIRPα. We also discuss how targeting PTM-regulating enzymes or specific modification motifs offers a promising therapeutic strategy to overcome ICB resistance. Understanding the PTMs landscape provides critical insight into resistance mechanisms and unveils promising opportunities for rational combination therapies aimed at reprogramming the immunosuppressive TME and enhancing antitumor immunity.

Background: Advanced metastasis produces cachexia, a complex skeletal muscle wasting syndrome that accounts for one-third of patient deaths. There is currently no approved drug therapy for cancer cachexia. Cancer-associated fibroblasts (CAF) within tumors have been hypothesized to contribute to cachexia, but the detailed mechanism(s) are unknown.

Methods: Myotubes were treated with conditioned media (CM) from CAF or CAF activated by cancer cells. Upregulated chemokines in the cancer-activated CAF CM were identified by cytokine array. The effects of chemokine neutralization were investigated using in vitro myotube cultures and in vivo mouse models. The mechanism of action was characterized by in vivo RNA Seq and validated in human muscle cells. Immunostaining delineated the chemokine expression pattern in a patient tumor type highly associated with cachexia.

Results: Cancer-activated CAF induced myotube atrophy. CXCL5 was as the major chemokine highly upregulated in the cancer-activated CAF. CXCL5 treatment alone induced myotube atrophy and inhibited myogenic ERK1/2 signaling, similar to cancer-activated CAF treatment. CXCL5 neutralization inhibited cachexia in mice co-injected with HCT 116 colon cancer cells and CAF. RNA Seq showed that CXCL5 neutralization upregulated hypertrophy-related PI3K-AKT-MyoG signaling and remodeled the muscle ECM. CXCL5 neutralization ameliorated muscle wasting induced by CXCL5 and IL-6 co-treatment, and also prevented atrophy in cancer-activated CAF CM-treated human myotubes. CAF were the major detectable source of CXCL5 in a patient tumor highly associated with cachexia.

Conclusion: CAF contribute to cachexia via cancer cell crosstalk that upregulates CXCL5 secretion. CXCL5 neutralization offers a novel therapeutic approach to maintain muscle mass in cancer patients.

Background: Fibrosis is a hallmark of various chronic diseases, for which there is no effective cure. Whilst the recombinant form of the human peptide hormone, relaxin (RLX), is being clinically evaluated for its cardioprotective including anti-fibrotic effects in heart failure patients, this is as an injectable which is invasive. This study therefore used biodegradable nanoparticles as a delivery platform to facilitate the prolonged activity and oral application of RLX and a related mimetic as therapeutics.

Methods: RLX was conjugated to glycine-functionalised biodegradable superparamagnetic iron oxide nanoparticles (SPION-RLX), enabling therapeutic levels of RLX to be systemically or orally delivered to a murine model of cardiomyopathy. The oral (p.o) application of SPION-RLX was evaluated via daily drinking water (125 ng/5mls/day) from days 7-14 or via oral gavage every 72 h (25 ng/day) from days 14-42 post-injury. The longer-term anti-fibrotic effects of p.o administered SPION-RLX (25 ng/day) or SPION-B7-33 (25 ng/day), a single-chain RLX derivative and relaxin family peptide receptor 1 (RXFP1) agonist were compared to the frontline ACE inhibitor, perindopril (60 ng/day) from days 14-42 post-injury.

Results: SPION-RLX was likely phagocytosed by surveiling RXFP1-expressing dendritic cells (DCs) and transported to the circulation and target site. This allowed for the systemic or oral administration of SPION-RLX to maintain its anti-fibrotic efficacy in mice with cardiomyopathy and restore organ dysfunction after 7 days of treatment. Single-cell transcriptomics provided insights into the phagosomal uptake of SPION-RLX which may have been mediated via scavenger receptors expressed by DCs. When orally administered every 72 h to mice with established cardiomyopathy over a 4 week period, SPION-RLX or SPION-B7-33 demonstrated greater anti-fibrotic efficacy than perindopril.

Conclusion: The conjugation of RXFP1-binding peptides to glycine-functionalised biodegradable SPIONs allowed for their circumnavigation of the gut, and prolonged activity as orally administered therapies. These findings have significant ramifications for the oral administration of peptide therapies in general.

Background: Early-onset pre-eclampsia (ePE) is a severe pregnancy complication characterized by dysregulated trophoblast functions and impaired placentation during early pregnancy, leading to substantial maternal and fetal morbidity. While circumstantial evidence indicates defective secretion from endometrial glands impairs placental development, direct evidence linking maternal glandular dysfunction to ePE pathogenesis remains elusive.

Methods: We established endometrial glandular organoids from women with ePE and healthy pregnancies, analyzing their secretomes by iTRAQ-based proteomics, RNAseq, and spatial transcriptomics. Functional effects of organoid secretomes on trophoblasts were examined in vitro. An endometrial-specific apolipoprotein D (APOD) knock-in mouse model was studied in vivo. APOD levels in first-trimester serum samples from women who later developed ePE were compared to healthy pregnancies.

Results: Secretomes from ePE derived endometrial organoids impeded spiral artery remodeling. Multiomic analyses revealed increased APOD production in both ePE organoids and decidual tissues. APOD overexpression disrupted trophoblast functions and endothelial vascular remodeling in vitro, and recapitulated ePE phenotypes in an APOD knock-in mouse model through PI3K/Akt-mediated placental ferroptosis and potential ER stress induction. Ferroptosis inhibition with Fer-1 rescued placental defects and PE symptoms in APOD knock-in mice. Elevated APOD levels in first-trimester serum samples from women who later developed ePE suggest its potential as an early biomarker.

Conclusion: This study provides the first direct evidence linking dysregulated endometrial gland function to defective placentation and ePE. APOD was identified as a crucial endometrial gland-secreted factor contributing to ePE, suggesting its potential as an early biomarker and therapeutic target.

Background: In gene therapy via genome editing, it is essential to precisely repair disease-associated gene sequences without introducing random mutations. However, achieving highly accurate genome editing remains challenging owing to the low efficiency of homology-directed repair (HDR)-mediated gene repair, which relies on template DNA. Therefore, if Cas9 mutants capable of enhancing HDR can be identified, they could enable more precise gene therapies.

Method: In this research project, we developed a screening system that uses the acquisition of diphtheria toxin resistance as an indicator of HDR efficiency in human cells and EGFP disruption as an indicator of off-target effect.

Results: By screening a library of SpCas9 variants with random mutations introduced into its nuclease domain, we identified a novel SpCas9 mutant with higher HDR efficiency than wild-type Cas9.

Conclusion: We explored the possibility of obtaining Cas9 mutants with high HDR efficiency via this screening system.