Journal of Biomedical Science最新文献

Background: The airway epithelium represents the first line of defense of the lungs, functioning both as a physical barrier as well as an active immune modulator. However, in the last years, pneumonia caused by the opportunistic pathogen Acinetobacter baumannii have become difficult to treat due to the increase of the number of extensively drug resistant strains. In this study, we report for the first time the use of an ex vivo air-liquid interface (ALI) model of differentiated human bronchial epithelial cells to unravel the early response to A. baumannii infection.

Methods: Epithelial integrity, tissue architecture, and goblet cell function were assessed through FITC-dextran permeability assays, hematoxylin and eosin staining, and indirect immunofluorescence. Transcriptomic profiling was performed to characterize host gene expression changes.

Results: Initial tissue damage began as early as at 4 h post-infection (hpi); at 24 hpi, goblet cell hypertrophy, reduced mucin secretion, and compromised epithelial integrity were highly evident. Transcriptomic data at 4 hpi revealed 668 differentially expressed genes (441 upregulated, 227 downregulated), mainly involved in a strong pro-inflammatory response and characterized by IL-8/CCL20-driven neutrophil recruitment and type 2 cytokine activation (IL-4, IL-13). Noteworthy, genes related to cytoskeletal organization, adhesion, and extracellular matrix remodeling were significantly altered, suggesting a bacterial mechanism to enhanced tissue dissemination. The PI3K-Akt survival pathway was inhibited, with downregulation of PIK3R1 and PIK3R2 genes, implying the induction of apoptosis/cell death and epithelial damage. Our findings are in agreement with previous in vivo studies, further strengthening the value of our ALI model in mimicking the early infection response of bronchial cells to A. baumannii infection.

Conclusion: Our data highlight the early molecular mechanisms underlying A. baumannii pathogenesis and open new avenues for future investigations for therapeutic interventions.

Chitosan is a cationic natural polymer composed of glucosamine and N-acetylglucosamine residues that are held together by a glycosidic bond. Chitosan has many excellent properties, including physicochemical properties, i.e., stability in the natural environment, chelation of metal ions, high sorption properties, biological properties such as biocompatibility and biological activity, ecological properties resulting from biodegradability, and physiological properties, which include non-toxicity, and economic affordability, and is used in various biomedical and industrial applications. The presented article highlights recent developments in chitosan-based formulations for the treatment of bacteria, viruses, cancer, or gastroesophageal reflux disease. Moreover, chitosan-derived biomaterials can also be used in regenerative medicine or food packaging to prevent contamination by pathogenic microorganisms. In summary, this is a valuable compilation in this emerging field that focuses on the biomedical application of chitosan-based biomaterials.

Background: Various epigenetic modifiers are involved in the regulation of gene expression during pathological cardiac hypertrophy-a critical event in the development of heart failure. Our previous research has demonstrated that protein arginine methyltransferase 5 (PRMT5) in cardiac fibroblasts is a crucial epigenetic writer implicated in pathological cardiac fibrosis. Moreover, treatment with a PRMT5 inhibitor also suppressed cardiac hypertrophy in mice after transverse aortic constriction (TAC) surgery. However, as the functional role of PRMT5 in cardiomyocytes remains to be fully elucidated in pathological cardiac hypertrophy and systolic dysfunction, this study aimed to clarify the gain-of-function of PRMT5 in cardiomyocytes.

Methods: Cardiac-specific PRMT5 transgenic (PRMT5-TG) mice were generated to evaluate the gain-of-function of PRMT5 in cardiac hypertrophy and dysfunction in male mice undergoing TAC surgery. Cardiac function and myocardial cell hypertrophy were evaluated in wild-type (WT) and PRMT5-TG mice after TAC surgery. To elucidate the molecular mechanistic basis through which PRMT5 induces cardiomyocyte hypertrophy, we examined epigenetic modifications of histones in cardiomyocytes.

Results: Echocardiography revealed that fractional shortening was reduced in PRMT5-TG mice compared to WT mice after TAC surgery. Both heart weight/BW and lung weight/BW ratios increased significantly more in PRMT5-TG than in WT mice. Histological analyses showed that cardiomyocyte diameter and perivascular fibrosis were elevated in PRMT5-TG mice in comparison to WT mice. Hypertrophic gene expression significantly increased in PRMT5-TG mice after TAC surgery. In primary cultured neonatal rat cardiac myocytes, EPZ015666, a specific inhibitor of PRMT5, and PRMT5 knockdown significantly inhibited phenylephrine (PE)-induced cell hypertrophy. Cardiac overexpression of PRMT5 promoted the acetylation of H3K9, a histone marker associated with cardiomyocyte hypertrophy, and the histone acetyltransferase activity of p300. Conversely, treatment with EPZ015666 reduced the acetylation of H3K9 induced by TAC surgery and PE treatment. Finally, we found that PRMT5 interacts with and methylates p300 at R200. The R200 point mutation in p300 abolished PRMT5-mediated enhancement of its histone acetyltransferase activity.

Conclusions: The gain-of-function of PRMT5 in cardiomyocytes exacerbates pressure overload-induced cardiac hypertrophy and left ventricular systolic dysfunction, at least partially, through p300 methylation and histone acetyltransferase activation.

Introduction: Autism spectrum disorder (ASD) is characterized by disruption of the gut-brain axis, which leads to behavioral, psychiatric, metabolic and gastrointestinal symptoms. Effective ASD treatments are limited. Research highlights the roles of the endocannabinoidome (eCBome) and gut microbiome (GM), both crucial for brain and gut function. This review summarizes research on therapeutic targets within the eCBome-GM-brain axis for ASD and related comorbidities.

Discussion: Evidence suggests that reduced levels of eCBome mediators, like oleoylethanolamide and anandamide, and altered cannabinoid type 1 and type 2 (CB1 and CB2) receptors activity may contribute to ASD symptoms, making them promising targets. Modulating the eCBome-GM-brain axis with inhibitors of fatty acid amide hydrolase (FAAH), transient receptor potential vanilloid 1, and monoacylglycerol lipase (MAGL) may improve repetitive, stereotypical, and sensory behaviors, and alleviate sociability impairments, depression and anxiety. However, inhibition of FAAH and MAGL may also induce ADHD-like behaviors, which can be reversed by CB1 inverse agonists. Targeting metabotropic glutamate receptor 5 to increase levels of the eCBome mediator 2-arachidonoylglycerol (2-AG) may benefit ASD-related behaviors. eCBome mediators such as 2-AG, 1/2-palmitoylglycerol and palmitoylethanolamide may also help manage ASD- and GI-related symptoms, and systemic inflammation. Other potential therapeutic targets that deserve further investigation are eCBome-related receptors G-protein-coupled receptor 55 and peroxisome proliferator-activated receptors-alpha and -gamma, and the cyclooxygenase-2/prostaglandin E2 pathway, which may address hyperactivity and repetitive behaviors. Additionally, mucin-degrading genera like Akkermansia and Ruminococcus may improve ASD-related GI symptoms such as hypersensitivity and inflammation. Selective antibiotics against specific Clostridium strains may improve irritability and aggression. In ASD with ADHD and OCD, treatments may involve modulating the CB1 and CB2 receptor, and bacterial families like Ruminococcaceae and Lachnospiraceae. Lastly, modulating the abundance of anti-inflammatory genera like Prevotella and Anaeroplasma, and taxa associated with gut health such as Roseburia may also offer therapeutic value.

Conclusion: The eCBome-GM-brain axis is a promising target for ASD treatment, meriting further clinical and preclinical research.

Background: The COVID-19 pandemic continues to affect the world in 2025. The rapid mutation of SARS-CoV-2 results in breakthrough infections and diminishes the efficacy of vaccines and anti-viral drugs. The severity of the disease varies across different variants, and the underlying mechanisms driving these differences remain unclear. This study explores the relationship between different Spike variants and cytotoxicity, aiming to determine whether the humanized decoy receptor ACE2-Fc can neutralize spikes from diverse variants, offering a solution to overcome rapid mutating SARS-CoV-2 induced immune escape.

Methods: We co-cultured 293 T-ACE2 cells with 293 T cells transfected with various Spike protein variants or used H1650-ACE2 cells transfected with these Spike variants. This allowed us to observe the effects of different Spike mutations, specifically focusing on cell fusion, cytotoxicity, and cytokine release from human peripheral blood mononuclear cells. Flow cytometry is employed to determine if ACE2-Fc can recognize different Spike variants. We also assess the ability of ACE2-Fc to inhibit infection, cell fusion, cytotoxicity, and cytokine release through pseudovirus infections or Spike protein transfections. Additionally, we use actual viruses from SARS-CoV-2 patients to validate the impacts of Spike mutations and the effectiveness of ACE2-Fc. Furthermore, human plasma is utilized to evaluate ACE2-Fc's capability to inhibit Spike-induced clot formation.

Results: We found that different Spike variants, particularly those with enhancements at the S2' site, increased cell-cell fusion capability, which correlated positively with cytotoxicity and cytokine IL-6 and TNF-α released from PBMCs. ACE2-Fc recognized spikes from wide-range of variants, including wild type, Alpha, Delta, Delta plus, Lambda, BA.2, BA.2.75, BA.5, BF.7, BQ.1, XBB.1, JN.1, KP.2, and KP.3, and effectively prevented these spike-expressing pseudo-viruses from entering host cells. Crucially, ACE2-Fc can prevent spike-induced cell fusion, thereby reducing subsequent cytotoxicity and the release of IL-6 and TNF-α from PBMCs. ACE2-Fc also effectively reduces plasma clot formation induced by trimeric spike proteins.

Conclusions: These findings demonstrated that ACE2-Fc could effectively combat the infection of rapidly mutating SARS-CoV-2, providing a potential solution to overcome immune evasion.

Background: Chagas disease, caused by Trypanosoma cruzi parasites, leads to chronic cardiac disease in 20-40% of infected patients, while the majority remain asymptomatic. The mechanisms and drivers of pathogenesis are still poorly understood, limiting treatment options. We tested for differences in immunoglobulin (Ig) and T cell receptor (TCR) repertoires and their association with T. cruzi parasite diversity (i.e. the cruziome) and host responses in naturally infected rhesus macaques.

Methods: Ig and TCR complementarity-determination region (CDR)3 sequences were identified from RNA-sequencing data from peripheric blood mononuclear cells of T. cruzi infected rhesus macaques and analyzed for composition and diversity.

Results: T. cruzi chronic infection was associated with a broader Ig clonotype repertoire, while TCR repertoire presented limited clonal expansion. There was a high individual diversity as most of these repertoires were private, although a few public clonotypes were detected. Remarkably, limited differences in Ig and TCR repertoires were found in association with the cruziome of infected macaques, even though parasite diversity seemed to play an important in shaping the immune response.

Conclusion: Chronic T. cruzi infection is associated with strong alterations in Ig and TCR repertoires in rhesus macaques, but these repertoires are minimally affected by parasite diversity and host responses to infection. A better understanding of these processes could help develop new immunotherapies against T. cruzi infection.

Background: Traumatic Brain Injury (TBI) is a major risk factor for neurodegenerative disorders such as Parkinson's disease (PD) and Alzheimer's disease (AD), with neuroinflammation playing a critical role in the secondary cell death that exacerbates the initial injury. While targeting neuroinflammation holds significant therapeutic promise, clinical trials of available anti-inflammatory agents have fallen short. 3-Mono-thiopomalidomide (3-MP), a novel immunomodulatory imide drug (IMiD), was designed to curb inflammation without the adverse effects of traditional IMiDs and was evaluated across models involving neuroinflammation.

Methods: 3-MP anti-inflammatory activity was evaluated across cellular (RAW 264.7, IMG cells) and mouse studies following lipopolysaccharide (LPS)-challenge (for pro- and anti-inflammatory cytokines/chemokines), and mice subjected to controlled cortical impact (CCI) moderate traumatic brain injury (TBI). 3-MP human cereblon binding, including neosubstrate and molecular modeling evaluation, as well as chicken teratogenicity, ex vivo mouse and human stability studies, and mouse pharmacokinetics were appraised.

Results: 3-MP binds human cereblon, a key protein in the E3 ubiquitin ligase complex, without triggering downstream cascades leading to thalidomide-like teratogenicity in chicken embryos. 3-MP reduces pro-inflammatory markers in LPS-stimulated mouse macrophage and microglial cell cultures, and lowers pro-inflammatory cytokine/chemokine levels in plasma and brain of mice challenged with systemic LPS without lowering anti-inflammatory IL-10. 3-MP readily enters brain following systemic administration, and achieves a brain/plasma concentration ratio of 0.44-0.47. 3-MP mitigates behavioral impairments and reduces activation of astrocytes and microglia in mice challenged with CCI TBI.

Conclusion: 3-MP represents a promising new class of thalidomide-like IMiDs with potent anti-inflammatory effects that offers potential for treating TBI and possibly other neurodegenerative diseases possessing a prominent neuroinflammatory component.

The innate immune system is the host's initial response to eliminate pathogens and repair tissue damage. Innate immune cells, such as macrophages and dendritic cells, use pattern recognition receptors (PRRs) to recognize microbial structures and stress-induced molecules released from dead or damaged cells, thereby initiating immune responses. Among PRRs, Toll-like receptors (TLRs) are well-studied and are located either on the cell surface or in endosomal compartments. Most endosomal TLRs specifically recognize nucleic acids and are thus referred to as nucleic acid (NA)-sensing TLRs. Upon activation, these receptors induce the production of inflammatory cytokines and type I interferons and initiate subsequent adaptive immunity. These immune responses work to suppress pathogens and inhibit tumor growth. However, excessive cytokine and interferon production can lead to various inflammatory diseases. This review focuses on mammalian nucleic acid-sensing TLRs, summarizing the molecular regulation of their activations, the impact of their dysregulation on human diseases, and therapeutic strategies that target these TLRs.

Background: This study aimed to investigate whether probiotics can ameliorate the H. pylori-induced Wnt/β-catenin-related COX-2 carcinogenesis signaling pathway by regulating the expression of microRNAs (miRNAs).

Methods: An H. pylori isolate and GES-1 cells were used to establish a COX-2-associated carcinogenesis axis. Western blot analysis was conducted to investigate Wnt/β-catenin and COX-2 signaling. Next-generation sequencing and DIANA Tools identified significant differences in miRNA expressions. The probiotics Lactobacillus acidophilus and Bifidobacterium lactis were used to study anti-carcinogenesis effects in GES-1 and miRNA-transfected GES-1 cells. The H. pylori-infected patients with intestinal metaplasia (IM) were randomly allocated into probiotic treatment or not after successful eradication, the IM regression was assessed by the 2nd esophagogastroduodenoscopy one year after treatment.

Results: Pretreatment with probiotics significantly reduced H. pylori-induced nuclear β-catenin phosphorylation and COX-2 levels in GES-1 cells. Among 9 significantly altered miRNAs, miR-185 was the only miRNA targeting the Wnt/β-catenin signaling pathway. H. pylori increased miR-185 expression and upregulated COX-2 carcinogenesis through the Wnt/β-catenin pathway, but not the JAK2/STAT3 pathway. B. lactis ameliorated H. pylori-induced miR-185 expression and nuclear β-catenin/COX-2 signaling in a dose-dependent manner. In the 6-month probiotic-treated patients had a significantly higher IM regression rate than controls (intention-to-treat: 37.5 vs 11.5%, OR: 4.60, 95% CI: 1.134-18.65, p = 0.025; per-protocol: 46.2 vs 17.6%, OR: 4.00, 95% CI: 0.923-17.33, p = 0.055). Patients without IM regression had significantly higher miR-185 levels in follow-up biopsies (p < 0.01).

Conclusions: Pretreatment with B. lactis ameliorated the H. pylori-induced COX-2 carcinogenesis pathway by reducing miR-185 expression, which targets Wnt/β-catenin signaling. (ClinicalTrials.gov, NCT05544396).

Background: Ubiquitin-specific peptidase 24 (USP24), a deubiquitinating enzyme, regulates protein stability by removing ubiquitin. This study investigates the role of UPS24 in lipid metabolism, inflammation, and fibrosis. It also explores the effect of targeting USP24 on metabolic disorders, focusing on high-fat diet (HFD)-induced obesity and liver diseases.

Methods: This study utilized CRISPR/Cas9 to create functional knockout mice (USP24^C1695A) and treated HFD-fed mice with USP24 inhibitor (USP24-i-101). The effects of USP24 inhibition or knockout on 3T3-L1 derived adipocytes, primary hepatocytes, hepatic stellate cells, and murine hepatocyte cell line AML12 (alpha mouse liver 12) cells were assessed with RNA-sequencing. Molecular mechanisms and the interaction between USP24 and PKA-Cα were studied with co-immunoprecipitation. Downstream signaling pathways involving CREB, SREBP1, PPARγ, and C/EBPβ, as well as USP24 role in liver inflammation and fibrosis, were studied using western blot and real-time PCR. Clinical and animal tissue samples were examined with immunohistochemistry to identify the correlations between USP24 and metabolic-associated liver diseases.

Results: Knockout or inhibition of USP24 reduced body weight, lipid accumulation, inflammation, and fibrosis in HFD-fed mice. The expression of genes related to lipogenesis, inflammation, and fibrosis was downregulated in USP24^C1695A mice and those treated with USP24 inhibitor (USP24-i-101). USP24 inhibition decreased lipid droplet accumulation in adipocytes and hepatocytes, suppressed inflammation in hepatocytes and AML12 cells, and reduced fibrosis in hepatic stellate cells. Mechanistically, USP24 expression was upregulated by PKA activation during adipocyte differentiation, leading to increased PKA-Cα stability and CREB phosphorylation, which promoted lipogenic gene expression. Free fatty acids (FFA) increased USP24 expression, activating NF-κB and TGFβ pathways to induce inflammation (Cox2) and fibrosis (α-SMA). USP24 was highly expressed in patients with metabolic dysfunction-associated steatohepatitis (MASH) and correlated with Cox2 and α-SMA levels.