International Journal of Biological Sciences最新文献

Background: Mitochondrial dysfunction is widely regarded as a central and early feature of Alzheimer's disease (AD) pathology. Prior studies suggest that the accumulation of amyloid precursor protein (APP) within mitochondria contributes to this dysfunction. Mutations in presenilin-1 (PS1), which account for most cases of early-onset familial AD (FAD), have also been shown to impair mitochondrial function. In this study, we investigated how APP influences PS1 mutation-induced mitochondrial dysfunction in human cortical neurons derived from patient induced pluripotent stem cells (iPSCs).

Methods: We analyzed transcriptomic and proteomic datasets from postmortem sporadic AD cortex to identify key dysregulated pathways. To functionally interrogate selected mechanisms, we established a panel of CRISPR/Cas9-engineered human iPSC lines, including PS1 mutant lines (PS1^+/F105C and PS1^+/A246E), an APP knockout derivative (APP^-/-_PS1^+/F105C), and their isogenic wild-type controls. These iPSCs were differentiated into cortical neurons for functional studies. Following directed differentiation into cortical neurons, biochemical analyses and super-resolution imaging were conducted to evaluate mitochondrial and neuronal phenotypes.

Results: Analyses of sporadic AD cortical transcriptomes and proteomes identified mitochondrial dysfunction as a prominently altered pathway. In agreement, cortical neurons differentiated from FAD PS1 mutant (F105C and A246E) iPSCs displayed mitochondrial defects and AD-related phenotypes, both of which were mitigated by APP knockout.

Conclusions: These findings provide critical insights into the bridging role of APP in FAD PS1 mutant-mediated mitochondrial dysfunction, advancing our understanding of the cellular mechanisms underlying AD.

Triple-negative breast cancer (TNBC) is an aggressive malignancy with limited treatment options. It lacks hormone receptors and human epidermal growth factor receptor 2. The immunosuppressive tumor microenvironment (TME), particularly cancer-associated fibroblasts (CAFs), significantly hinders chimeric antigen receptor (CAR)-T cell therapy success. Novel strategies to overcome TME-mediated immunosuppression are urgently needed. We evaluated whether targeting CAFs with fibroblast activation protein alpha (FAP)-coated, 8-O-methylfusarubin-loaded nanoparticles called anti-FAP@OMF-NPs could enhance the anti-tumor efficacy of folate receptor alpha (FRα)-specific CAR-T cells against TNBC in a 3D cancer cells-CAFs co-culture heterospheriod (HS) model. FRα and FAP expression in TNBC cells and primary breast CAFs were assessed using immunofluorescence and flow cytometry. Anti-FRα-CAR-T cells were generated via lentiviral transduction and characterised for activation markers. Cytotoxic activity of CAR-T cells, anti-FAP@OMF-NPs, and their combination was evaluated in 3D-HS comprising FRα-high TNBC cells and FAP-high CAFs. A fluorescent transfection assay measured cell viability. Cytokine bead arrays quantified IFN-γ, granzyme A, and granzyme B levels to assess anti-tumor immune activation. PC-B-130CAFs and PC-B-132CAFs demonstrated high FAP expression compared with PC-B-004CAFs and normal human dermal fibroblast cells (HDFa). Anti-FRα-CAR-T cells selectively targeted FRα-positive TNBC cells whilst showing minimal cytotoxicity towards normal MCF-10A cells. Anti-FAP@OMF-NPs induced potent cytotoxic effects specifically in FAP-expressing CAFs. Combined treatment significantly enhanced the destruction of MDA-MB-231/130CAF and MDA-MB-231/132CAF HSs compared with monotherapies. This combination increased secretion of IFN-γ, granzyme A, and granzyme B from anti-FRα-CAR-T cells. Targeting CAFs using anti-FAP@OMF-NPs enhances the cytotoxic efficacy of FRα-specific CAR-T cells in TNBC. This combinatorial approach offers a promising strategy to overcome TME-mediated immunosuppression. These findings support further development of dual-targeting approaches to improve therapeutic outcomes in TNBC.

Acute Myeloid Leukemia (AML) is a heterogeneous hematologic malignancy driven by genetic and epigenetic alterations, where super-enhancers (SEs) play key oncogenic roles, representing promising therapeutic targets in AML. Through H3K27ac ChIP-seq profiling of 7 AML cell lines and 13 primary samples, we identified USP20 as the deubiquitinase that most frequently associated with super-enhancers. Public database analysis confirmed USP20 overexpression in AML and its correlation with adverse prognosis. Genetic knockdown of USP20 via shRNA significantly induced apoptosis and suppressed proliferation in AML cells in vitro, while in vivo depletion of USP20 attenuated leukemia development and improved overall survival. AS1517499, a novel USP20 inhibitor identified via virtual screening, recapitulated these anti-leukemic effects in vitro and in vivo with low toxicity. Mechanistically, USP20 interacts with CTNNB1 and stabilizes the CTNNB1 protein via deubiquitination. Cut&tag analysis indicated that USP20 co-localizes with CTNNB1 on the genome, where they jointly regulate target genes in AML. Collectively, our study identified USP20 as a super-enhancer-regulated oncogene maintaining AML cell survival and proliferation through CTNNB1 stabilization. Pharmacologic targeting of USP20 with AS1517499 presents a promising therapeutic strategy targeting the SE-USP20- CTNNB1 axis.

The nuclear factor kappaB (NF-κB) is a critical regulator in immune development, responses, and tumorigenesis. A range of signals can stimulate its activation by interacting with the inhibitor of κB (IκB) and IκB kinase (IKK) through the canonical pathway or non-canonical pathway. Activation of NF-κB results in this transcriptional factor binding with specific κB sites of different target genes. The NF-κB signaling pathway is particularly associated with liver diseases including hepatitis B virus (HBV) infection. HBV proteins have been shown to interact with different members of the NF-κB system, either enhancing or suppressing its activity. Here, we summarize current understanding on the interaction between HBV proteins and the NF-κB pathway, along with its association with liver diseases and potential therapeutic targets.

ARID1A, a key component of the SWI/SNF chromatin remodeling complex, is a tumor suppressor frequently inactivated in many cancer types, including endometrial cancer. Exploiting ARID1A deficiency has emerged as a therapeutic strategy in these types of cancer. We here employed a synthetic lethal drug screen for ARID1A and found that JAK/STAT3 pathway is a therapeutic vulnerability in ARID1A-deficient endometrial cancer. Inhibition of JAK/STAT3 selectively inhibited the growth of ARID1A deficient endometria cancer cells in vitro and in a mouse xenograft tumor model. Mechanistically, ARID1A deficiency activates JAK/STAT3 signaling through promoting the transcription of the pleiotropic cytokine Oncostatin M (OSM). Autocrine activation of JAK/STAT3 signal by OSM in ARID1A-deficient endometrial cancer cells promotes PLK1 levels, inducing mitotic abnormality. These cells are highly vulnerable to JAK/STAT3 and PLK1 inhibitors for mitotic arrest and death. ARID1A and OSM protein levels are inverse correlated in patients with endometrial cancer, where elevated OSM levels are associated with poor patient survival. Our study indicates that OSM-STAT3-PLK1 axis inhibition presents a new therapeutic approach for endometrial cancer with ARID1A loss.

Sirtuin 1 (SIRT1) and Sirtuin 2 (SIRT2) are NAD⁺-dependent deacetylases that regulate cancer metabolic stress, exerting their effects primarily through post-translational modification of metabolic enzymes and transcription factors. They modulate glucose, lipid, and mitochondrial metabolism, as well as immune metabolism responses within the tumor microenvironment. Depending on cellular context, they can promote or suppress tumor growth by directing energy production, redox balance, and metabolic adaptation. These context-dependent and often opposing activities constitute a Yin-Yang mode of regulation in cancer metabolism, reflecting a dynamic balance between metabolic activation and constraint. Autophagy has emerged as a critical metabolic integration node regulated by both SIRT1 and SIRT2, linking nutrient sensing, mitochondrial quality control, and stress adaptation. This review summarizes recent advances in understanding how SIRT1 and SIRT2 coordinate tumor metabolism and discusses therapeutic strategies that target their regulatory balance to reprogram cancer metabolism. SIRT2 also functions as a metabolic checkpoint that restrains CD8⁺ T cell effector metabolism, providing a rationale for combining SIRT2 inhibition with immune checkpoint blockade in metabolically stressed tumor microenvironments.

Patients with ulcerative colitis (UC) exhibit heightened depression risk, linked to microbiota-gut-brain axis dysfunction. This study isolated a novel low-molecular-weight Schisandra chinensis polysaccharide (SCP) that ameliorated UC and comorbid depression by remodeling gut microbiota, redirecting tryptophan (Trp) metabolism toward the indole pathway, and activating aryl hydrocarbon receptor (AhR). Structurally, SCP features a →4)-α-D-Glcp backbone with O-6 branched chains. In dextran sulfate sodium-induced UC mice, SCP mitigated colonic inflammation, restored intestinal barrier integrity, and improved depression-like behaviors by repairing blood-brain barrier, reducing neuroinflammation, preserving hippocampal neurons, and modulating synaptic plasticity. Multi-omics revealed SCP enriched beneficial microbiota (e.g., Limosilactobacillus reuteri) and rebalanced Trp metabolism along the gut-brain axis. SCP suppressed the hyperactive kynurenine (Kyn) pathway (reduced Kyn/Trp ratio) while elevating indole-3-propionic acid (IPA) levels in colon, serum, and hippocampus. Functioning as a pivotal molecule, IPA exerted dual anti-inflammatory effects in both colon and hippocampus via AhR activation and NF-κB inhibition. Antibiotic depletion and fecal microbiota transplantation validated SCP's microbiota-dependent efficacy, while IPA supplementation recapitulated SCP's benefits. AhR inhibition abolished SCP's therapeutic actions, confirming AhR as the critical target. Collectively, these findings propose a novel therapeutic strategy for UC and associated depression, highlighting SCP's potential value in targeting the Trp metabolism-AhR axis.

Particulate matter exposure, especially diesel exhaust particles (DEP), can exacerbate neutrophilic airway inflammation which presents corticosteroid insensitivity, resulting in the loss of asthma control. The underlying biological mechanisms remain poorly understood, thereby impeding the development of innovative therapeutic strategies. Itaconate (ITA) is an anti-inflammatory metabolite that suppresses excessive immune activation in multiple pathological conditions. In this study, we identified that neutrophil acted as an essential regulator in DEP-induced corticosteroid-resistant asthma mouse models. Multi-omics and single-cell sequencing analysis found that aconitate decarboxylase 1 (ACOD1)/ITA was significantly elevated in neutrophils via the NF-κB signaling pathway in DEP-exacerbated asthma. Knockout of Acod1 exacerbated asthma pathogenesis, while treatment with exogenous ITA or 4-octyl itaconate (4-OI) conferred protection against airway inflammation and reversed corticosteroid resistance in asthma mouse models. Mechanistically, neutrophil-derived ITA helped maintain immune homeostasis by reducing the formation of neutrophil extracellular traps (NETs), which further inhibited Th17 cell differentiation in DEP-exacerbated asthma. Our results delineate the dual immunoregulatory function of neutrophils in DEP-induced corticosteroid-resistant asthma, wherein they simultaneously propagate inflammation through NETosis and Th17 activation while restraining immune hyperactivation via ITA-mediated metabolic regulation. ITA serves as a negative regulator of airway inflammation and corticosteroid resistance, highlighting its promising therapeutic potential in asthma.

The PD-1/PD-L1 axis represents a well-established immunotherapeutic target. Nevertheless, anti-PD-1/PD-L1 therapeutics have shown limited efficacy in the management of solid tumors, particularly in the context of hepatocellular carcinoma (HCC). Among the various factors contributing to the resistance to anti-PD-1/PD-L1 therapy, tumor-associated macrophages (TAMs) have attracted significant interest because of the immunosuppressive properties. NPLOC4 has been explored as an antitumor drug target. However, whether NPLOC4 functions in TAMs or immunotherapy is unclear. Here, we report a new role for NPLOC4⁺ TAMs in inhibiting antitumor immune responses by facilitating the proteasomal degradation of RIG-I. Clinical specimens revealed that the number of NPLOC4⁺ TAMs are negatively correlated with the prognosis of patients with HCC. Proteomic data and in vitro/in vivo experiments demonstrated that NPLOC4 inhibits the type I interferon pathway in TAMs, promotes M2 polarization, and suppresses CD8⁺ T-cell infiltration, thereby creating an immunosuppressive microenvironment in HCC. NPLOC4 can bind to RIG-I and mediate its ubiquitination-mediated degradation, thus suppressing the type I interferon pathway. Animal studies have indicated that disulfiram/copper (DSF/Cu) can target the NPLOC4 protein, and that the combination of DSF/Cu with PD-1 therapy significantly inhibits HCC growth. In conclusion, targeting NPLOC4⁺ TAMs can significantly increase the resistance of HCC to anti-PD-1 therapy, which makes it a promising novel immune target for HCC treatment.

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) is a prevalent chronic liver condition characterized by pathological fat accumulation in hepatocytes, with a global prevalence of approximately 30% that continues to rise. Current treatment options are limited, highlighting an urgent need for novel therapeutic strategies. This review systematically examines the emerging promise of oligonucleotide-based drugs for MASLD treatment, including antisense oligonucleotide (ASO), small interfering RNA (siRNA), microRNA (miRNA) mimic or inhibitor, small activating RNA (saRNA) and splicing-switching oligonucleotide (SSO). We summarize the mechanisms of action of these therapeutics, which enable precise targeting of genes involved in MASLD pathogenesis. Furthermore, the review explores advanced delivery systems, particularly N-acetylgalactosamine (GalNAc) conjugation, which enhances hepatocyte-specific targeting. Finally, we discuss the current challenges facing oligonucleotide drug development and outline future directions for this rapidly advancing field, underscoring its potential to revolutionize MASLD management.