Nonalcoholic fatty liver disease (NAFLD) is a prevalent chronic condition, yet therapeutic targets remain elusive. Nicotinamide phosphoribosyl transferase (NAMPT) and six-transmembrane epithelial antigen of the prostate 4 (STEAP4) are integral regulators in various metabolic disorders. This study investigates the role and molecular mechanisms of NAMPT in NAFLD pathogenesis. We found that inhibiting NAMPT or knockdown of silent information regulator 1 (SIRT1) exacerbates liver steatosis and impairs hepatic antioxidant defenses in high-fat diet (HFD)-induced obese mice, while reducing STEAP4 expression, suggesting that NAMPT and SIRT1 are pivotal in NAFLD progression and may regulate STEAP4. The role of NAMPT in SIRT1 expression involves nicotinamide adenine dinucleotide (NAD) synthesis. Our results indicate that inhibiting SIRT1's deacetylase activity impairs CCAAT/enhancer-binding protein β (C/EBPβ) deacetylation and consequently its function. Additionally, STEAP4, previously identified as a C/EBPβ target, can upregulate the expression and nuclear translocation of NF-E2-related factor 2 (NRF2) to combat oxidative stress in NAFLD. This study confirms that NAMPT ameliorates NAFLD via the SIRT1-C/EBPβ-STEAP4-NRF2 signaling axis in HFD-induced obese mice, proposing a novel strategy for the prevention and treatment of NAFLD.

Tumorigenesis exhibits complex interactions with the vascular system. Targeting angiogenesis represents an emerging strategy for remodeling the tumor microenvironment. The Notch signaling pathway, a key regulatory mechanism, orchestrates tumor angiogenesis by modulating endothelial cell differentiation and vascular homeostasis. However, the clinical translation of Notch-targeted therapies is limited by severe toxicities due to lack of tissue specificity. Posttranslational modifications (PTMs) chemically regulate protein functions, thereby influencing multiple signaling cascades including Notch signaling. Notably, Notch-associated PTMs are essential for signal transduction integrity. Some types in PTMs, such as glycosylation and ubiquitination, are the core for maintaining the integrity of the Notch signaling pathway. Dysfunctional Notch-related PTMs disrupt signal fidelity and drive pathological angiogenesis. This review systematically explores: (i) crosstalk between Notch signaling and tumor angiogenesis, (ii) regulatory roles of PTMs on Notch molecules in tumor angiogenesis, and (iii) therapeutic potential of targeting Notch-related PTMs for anti-angiogenic strategies in tumor. We aim to elucidate the molecular nexus of PTMs-Notch-angiogenesis in tumor progression. Furthermore, we discuss therapeutic challenges in modulating Notch signaling pathway-dependent PTMs within tumor angiogenesis, focusing on critical barriers to their clinical translation in oncology.

Emerging evidence implicates tumor stemness features-characterized by self-renewal capacity, microenvironment adaptability, and immune evasion mechanisms-as critical determinants of therapeutic resistance and recurrence in hepatocellular carcinoma (HCC). KCNJ12, an inward rectifier potassium channel, has shown electrophysiological functions in cardiomyocytes; however, its oncogenic potential and the role in hepatocarcinogenesis involving cancer stemness regulation remain unexplored. This study systematically characterizes the KCNJ12-mediated molecular pathway driving HCC tumorigenicity. Lentiviral-mediated overexpression and knockdown models with functional assessments revealed KCNJ12's critical role in maintaining cancer cell self-renewal capacity. Mechanistic studies using cycloheximide chase assays, Wnt pathway modulators (LiCl, SKL2001, and Salinomycin), and protein interaction analyses demonstrated that KCNJ12 stabilizes β-catenin through the physical interaction with lipoprotein receptor-associated protein 6 (LRP6), disrupting AXIN/APC/GSK-3β complex assembly and subsequent proteasomal degradation. The nuclear β-catenin accumulation drives TCF/LEF-dependent transcriptional activation and thus enhances the self-renewal capacity of HCC cells. Our findings establish KCNJ12 as a novel Wnt/β-catenin regulator and propose dual therapeutic strategies against HCC-mediated chemoresistance: pharmacological suppression of KCNJ12 channel activity and targeted disruption of KCNJ12-LRP6 protein interactions. This mechanistic framework advances our understanding of stemness regulation in HCC and provides feasible targets for developing next-generation anti-HCC therapies.

Mitochondria are essential organelles responsible for generating ATP through oxidative phosphorylation (OXPHOS). Despite having their own genome, mitochondria rely on a complex interplay with nuclear-encoded proteins to maintain their function, as mutations in these proteins can lead to mitochondrial dysfunction and associated diseases. Mutations in the SLIRP (stem-loop interacting RNA-binding protein) gene are known to cause severe human mitochondrial diseases, and loss of SLIRP function can impair mitochondrial mRNA stability and translation. However, in vivo roles of the SLIRP protein remain inadequately understood. Drosophila melanogaster serves as a powerful model for studying mitochondrial function, particularly in the context of reproductive system development and gametogenesis. In this study, we focus on the role of the fly Slirp2 in oogenesis. Loss of Slirp2 impairs mitochondrial protein synthesis, leading to reduced OXPHOS efficiency, diminished ATP production, and disrupted insulin/mTOR signaling. These defects ultimately promote reactive oxygen species-induced programmed cell death, resulting in infertility. Our findings provide novel insights into the mechanistic role of Slirp2 in mitochondrial function and reproductive biology in vivo. We demonstrate that Slirp2 exhibits species-specific regulation of mitochondrial translation, revealing its complex, context-dependent function. These results have broader implications for understanding mitochondrial diseases, suggesting that the effects of Slirp2 mutations may vary across different organisms and tissue types.

The canonical Wnt/β-catenin pathway critically regulates cardiac calcium homeostasis, yet its interplay with microenvironmental factors remains unclear. This study reveals that fetal bovine serum (FBS) treatment alters Wnt-mediated calcium dynamics in AC16 cardiomyocytes. While Wnt activation elevates cytosol calcium in serum-free conditions, FBS supplementation reverses this response: Wnt inhibitors (SFRP2, XAV939, and LF3) induce cytosol calcium accumulation, while the activators (LiCl and Wnt3a) lose efficacy. Mechanistically, FBS ablates RyR2 expression, uncoupling calcium-induced calcium release. Consequently, calcium handling shifts to SERCA2a-dependent regulation. We identify myoregulin (MLN) as a pivotal effector of the Wnt/β-catenin signaling with Wnt inhibition upregulating MLN to suppress SERCA2a activity. MLN knockdown (90% suppression) abolishes the effects of Wnt inhibitors on SERCA2a function and calcium distribution patterns. RyR2 reconstitution in FBS-treated cells restores calcium release but not Wnt activation responses, confirming the dominant role of MLN. Crucially, a combination of RyR2 overexpression and MLN depletion fully restores Wnt-calcium responses, phenocopying serum-free conditions. Our work establishes a serum-dependent regulatory axis where Wnt/β-catenin signaling maintains calcium homeostasis by repressing MLN, thereby preserving SERCA2a function. This FBS-induced shift mirrors pathological adaptations in heart failure, positioning MLN as a therapeutic target for calcium-handling disorders.

ADP-ribosylation factor (Arf)-specific GTPase-activating proteins (ArfGAPs) regulate cell migration through interactions with small G proteins, including Arfs. In ArfGAPs, the Bin/Amphiphysin/Rvs (BAR) domain plays a key role in membrane binding and curvature induction, yet the molecular mechanisms underlying these processes remain unclear. Here, we investigate the function of the BAR domain and its adjacent pleckstrin homology (PH) domain of ACAP4 in cell migration. We demonstrate that the BAR-PH tandem of ACAP4 induces membrane curvature, promotes cell migration, forms condensates in vitro, and exhibits membrane-associated distribution in cells. The crystal structure of the ACAP4 BAR domain, determined at 2.8 Å resolution, reveals multiple positively charged surface patches. Structural modeling further identifies conserved positively charged residue pairs in the PH domain, which collectively mediate electrostatic interactions essential for both membrane remodeling and membrane localization. Mutagenesis experiments confirm that these regions are required for ACAP4's subcellular localization and pro-migratory activity. Furthermore, we identify that the actin-binding protein Ezrin interacts with a specific C-terminal region of ACAP4 to regulate its function. Ezrin binding enhances condensate formation and enables full-length ACAP4 to associate with membranes and promote cell migration, particularly when co-expressed with the activated Ezrin (T567D). Together, our findings uncover the molecular basis by which ACAP4 coordinates membrane remodeling and cytoskeletal dynamics, offering new insights into the mechanisms that drive cell migration.

Kawasaki disease (KD) is an acute febrile systemic vasculitis associated with the development of coronary artery lesion and coronary artery aneurysm. This condition is characterized by sustained vascular inflammation and endothelial dysfunction, in which pyroptosis serves as a pivotal driver of inflammatory response. However, the molecular mechanisms linking pyroptosis to endothelium injury and KD pathogenesis remain poorly understood. Analysis of public datasets revealed a marked decrease in T-cadherin (T-cad, CDH13) expression in cardiac tissues from KD patients and KD model mice compared to controls. In vitro and in vivo experiments revealed the reduced T-cad expression in both the treated human umbilical vein endothelial cells (HUVECs) and the abdominal aorta of Lactobacillus casei cell wall extract (LCWE)-induced KD mice. RNA sequencing analysis of HUVECs with siRNA-mediated T-cad knockdown showed significant enrichment of genes involved in pro-inflammatory cascades and pyroptosis-associated pathways. Western blot analysis further validated the upregulation of pyroptosis-associated proteins, including NLRP3, caspase-1, GSDMD, IL-1β, and IL-18, in the T-cad knockdown group compared to controls. These findings were supported by functional assays demonstrating the increased lactate dehydrogenase release, higher TUNEL-positive cells, and elevated reactive oxygen species (ROS) levels in the T-cad knockdown group. Collectively, our results indicate that inflammatory stimuli downregulate T-cad expression in endothelial cells, subsequently reducing superoxide dismutase 2 (SOD2) expression and its enzymatic activity. This leads to ROS accumulation, which activates the NLRP3 inflammasome and initiates pyroptosis. Thus, T-cad deficiency induces pyroptosis in HUVECs via the activation of the SOD2/ROS/NLRP3 pathway. These findings highlight the pivotal role of T-cad deprivation-mediated endothelial cell pyroptosis in the initiation and progression of KD, providing novel insights into its pathophysiology and potential therapeutic targets.

Fam3C, also known as Interleukin-like EMT inducer (ILEI), is an established regulator of the epithelial to mesenchymal transition and breast cancer stem cell phenotypes. Multiple cancer cell models and orthotopic animal model experiments have demonstrated a role for Fam3C in tumor progression and metastasis. Here, we establish Fam3C's impact on triple negative breast cancer patients and genetically engineered mouse models of spontaneous breast cancer tumor progression. Though Fam3C is a known secreted protein, we discovered its retention in the Golgi apparatus through anchoring of its signal peptide into the membrane before its signal peptide and pro-peptide are processed and removed. While retained in the Golgi apparatus, Fam3C affects the overall morphology of the organelle and its biological functions, including alterations in protein secretion and invasive potential. Expanding our knowledge of the biological mechanisms behind EMT will help develop therapies to specifically target cells with increased metastatic potential in triple negative breast cancer.

The mechanism underlying the selective loss of dopaminergic neurons in Parkinson's disease (PD) is still not understood at present. MPTP, an illicit drug contaminant, can selectively induce parkinsonism in humans and animals which is very similar to idiopathic PD. Like MPTP, 6-hydroxydopamine (6-OHDA) is another neurotoxicant also capable of selectively inducing parkinsonism in animal models. In this paper, a unifying hypothesis is proposed, which offers a plausible explanation for the pathogenic mechanism of parkinsonism induced by MPTP and 6-OHDA. This hypothesis has three core elements: (i) The vesicular monoamine transporter 2 (VMAT2) is the transporter responsible for the reverse transport (efflux) of the misplaced cytosolic dopamine (DA). (ii) Activation of VMAT2-mediated DA reverse transport is caused by elevated oxidative stress, often resulting from the buildup of cytosolic DA in dopaminergic neurons. (iii) VMAT2 is a major target of MPP+ (a toxic metabolite of MPTP) and 6-OHDA, and inhibition of VMAT2-mediated DA reverse transport by MPP+ or 6-OHDA will result in the buildup of cytosolic DA, and its subsequent oxidation/auto-oxidation will further heighten oxidative stress and generate chemically-reactive, neurotoxic DA derivatives. These DA-associated oxidative changes jointly contribute to the selective injury to dopaminergic neurons and the induction of parkinsonism. This mechanistic hypothesis agrees with a large body of experimental observations, and also offers a mechanistic explanation for many experimental findings. Additionally, this hypothesis offers mechanistic insights into the pathogenic role of α-synuclein in human PD based on its strong ability to suppress VMAT2-mediated DA reverse transport in dopaminergic neurons.

The transcription factor ZBTB7B has been identified as a potential tumor suppressor through a CRISPR-Cas9-based functional screen of tumor-associated genes, as overexpression of ZBTB7B could significantly suppress tumor growth in the models of breast cancer brain metastasis, which prompted our further exploration of its inhibitory role in glioma. To elucidate the underlying mechanisms of this suppressive effect, lentiviral-mediated ZBTB7B overexpression was established in U118 and GL261 glioma cell lines, and systematic evaluation of tumorigenic capacity was performed through in vitro and xenograft assays. The results showed that ZBTB7B transcriptionally activated GPR17 expression, which suppressed protein kinase A phosphorylation, amplified mitochondrial reactive oxygen species generation, and triggered Caspase3-dependent apoptosis. Meanwhile, ZBTB7B upregulated CXCL10 secretion, which markedly enhanced CD4+ and CD8+ T cell accumulation. Clinical validation through multiplex immunofluorescence staining on a tissue microarray of 129 glioma samples revealed a progressive loss of ZBTB7B protein expression across WHO grades II to IV, inversely correlating with tumor malignancy. These findings demonstrate ZBTB7B as a dual-function tumor suppressor that concurrently induces intrinsic apoptosis and remodels the tumor immune microenvironment in glioma toward a 'hot' phenotype. Therefore, we propose ZBTB7B reactivation as a novel therapeutic strategy for glioma.

Obese individuals even with normal glucose tolerance (NGT) are at higher risk for developing type 2 diabetes (T2D), and obesity is associated with inflammation. However, mechanisms linking inflammation to beta-cell function and insulin sensitivity in NGT individuals are not fully understood. We aimed to investigate the relationships between inflammation-related proteins (IRPs) and insulin dynamics in NGT subjects. The explorations were conducted using data from 1109 non-diabetes subjects aged 40-44 with normal or excess body weight and 21 Chinese NGT subjects aged 22-32 with accurate metabolic assessment. IRPs were detected with Olink technology. Insulin sensitivity and beta-cell function were evaluated with hyperinsulinemic-euglycemic clamp and hyperglycemic clamp. Eight associators were identified with obesity in NGT subjects, among which MCP-3, IL-6, TWEAK, HGF, and CST5 also showed associations in non-diabetes people. Four IRPs were linked to insulin sensitivity, with IL-24 being a novel finding. Seven IRPs were related to beta-cell function, including novel associators CD244, CD40, and IL-15RA. Moreover, most IRPs were interconnected, with IL-6 as the hub. In conclusion, insulin sensitivity and beta-cell function are related to IRPs involved in chemotaxis, activation of immune cells, and cell proliferation, which might provide valuable information for the understanding of the mechanisms associated with T2D pathogenesis.

Amyloid precursor protein (APP), a type I transmembrane protein, is closely related to the pathogenesis of Alzheimer's disease (AD). Amyloid beta (Aβ) is generated by sequential processing of APP in the Golgi apparatus and endosomes, and its toxicity leads to neuron dysfunction and neurodegeneration. APP is selectively shuttled between intracellular membrane compartments and ultimately transported into lysosomes. However, the mechanisms underlying APP sorting signals and lysosomal degradation are largely unclear. In this study, we show that the von Hippel‒Lindau protein (VHL), a subunit of an E3 ligase, recognizes the cytoplasmic domain of APP and mediates its ubiquitination. VHL-mediated ubiquitination facilitates the sorting of membrane APP into intraluminal vesicles of multivesicular bodies (MVBs) and subsequent degradation in lysosomes. Therefore, the loss of VHL accelerates Aβ plaque deposition and memory deficits in AD model mice. Our findings reveal the role of VHL in restricting AD pathogenesis through ubiquitination-dependent MVB sorting and lysosomal degradation of APP.

The functional specificity of tubulin isotypes has been demonstrated by various neurological diseases caused by an increasing number of mutations in tubulin isotypes. TUBA8 is specifically localized in cerebellar Purkinje cells, which exhibit the most elaborate dendritic trees in the central nervous system. However, the role and related molecular mechanism of TUBA8 in regulating neuronal dendritic morphology remain poorly understood. Here, we report that TUBA8 is required for neuronal dendrite development. As the most divergent member in α-tubulin isotypes, the expression of TUBA8 in Purkinje cells starts at P0, plateaus at P10 and sustains into adulthood. Loss of TUBA8 in Purkinje cells induces global dendritic height defects in multiple lobules during development and aging. Meanwhile, TUBA8 deficiency causes age-dependent decreased locomotor activity and anxiety-like behavior. In contrast to TUBA8, TUBA4A, another tubulin isotype highly expressed in Purkinje cells, is not required for dendrite development. Furthermore, the 40th alanine, which differs with any other α-tubulin isotype and cannot be modified by acetylation, methylation or lactylation, mediates the promoting effect of TUBA8 in neuronal dendrite development. This study reveals a specific role of TUBA8 in regulating neuronal dendritic morphology and highlights the importance of 40th amino acid in implementing functions of α-tubulin isotypes.

Metabolic adaptability, controlled by transcription factors or oncogenes, is critical for the survival of cancer cells. However, the mechanism by which the transcription factor forkhead box protein O1 (FOXO1) regulates the proliferation and survival of malignant tumor cells under high levels of reactive oxygen species (ROS) remains poorly understood. Here, we found that FOXO1 endows cancer cells with a strong antioxidative capacity and rapid proliferation. By upregulating the expression of glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme in the pentose phosphate pathway, FOXO1 promotes the synthesis of nicotinamide adenine dinucleotide phosphate and ribose 5-phosphate and thus enhances the antioxidative and proliferative capabilities of cancer cells. Induction of G6PD expression in FOXO1-deficient cells mitigates tumor growth inhibition and alleviates ROS level elevation. These results establish a critical role for FOXO1 in the regulation of G6PD during the antioxidative and proliferative processes of cancer cells.

Flaviviridae Dengue virus (DENV) and Zika virus (ZIKV) have posed significant threats to global public health in the past decades. Despite extensive study on therapeutic strategies against these viruses, effective treatment options are still lacking. Within host cells, the cytoskeletal vimentin intermediate filament network facilitates viral replication during DENV and ZIKV infection by shrinking and forming a cage-like structure. Our previous work indicated that MEK1/2 inhibitors can induce the dispersion of vimentin, but their potential impact on flavivirus infection remains unclear. Here, we observed that the MEK1/2 signaling pathway is activated in host cells infected with DENV and ZIKV. Treatment with MEK1/2 inhibitors significantly impaired the replication of both viruses. Further mechanistic studies revealed that MEK1/2 inhibitors prevent viral infection by promoting the dispersion of intracellular vimentin network, thereby disrupting the cytoskeletal structure required for viral replication. Our findings not only expand the understanding of vimentin regulatory mechanisms from a cellular biology perspective but also provide a new perspective on MEK1/2 inhibition as a potential anti-DENV and anti-ZIKV strategy.

Tumor-associated fibroblasts (CAFs) regulate tumorigenesis, tumor cell proliferation, and metastasis via secreting related regulatory factors; however, the evidence for CAFs in regulating development of upper tract urothelial carcinoma (UTUC) remains unclear. Here, by utilizing single-cell RNA sequencing (scRNA-seq), single-nucleus RNA sequencing (snRNA-seq), SpaTial enhanced resolution omics-sequencing (Stereo-seq), and UTUC immunofluorescence chip cohort to construct the first comprehensive microenvironmental atlas of CAFs, we investigated the roles of CAFs in UTUC progression. Through hierarchical clustering and the copy number variation (CNV) scores of UTUC epithelial cells, we first classified tumor epithelial cells into high-malignant, medium-malignant, and low-malignant potential categories. We found that the myofibroblastic CAFs1 (myCAFs1) and myCAFs2 subclusters exhibited significant interaction signals with all three types of epithelial cells, among which high-malignant epithelial cells (HMECs) exhibited pronounced communication signals with CAFs, and FN1 and COL1A1 generated by CAFs played critical roles in this process, suggesting that the progression of UTUC may be attributed to the activation of tumor cells by CAFs. Both myCAFs1 and myCAFs2 simultaneously affect bladder urothelial carcinoma (BUC) prognosis, with the risk model showing good consistency across cohorts. The study constructs a multi-omics landscape of UTUC and identify common prognostic markers shared with BUC.

Tyrosine kinase inhibitors (TKIs) combined with immunotherapy regimens are now widely used for treating advanced hepatocellular carcinoma (HCC), but their clinical efficacy is limited to a subset of patients. Considering that the vast majority of advanced HCC patients lose the opportunity for liver resection and thus cannot provide tumor tissue samples, we leveraged the clinical and image data to construct a multimodal convolutional neural network (CNN)-Transformer model for predicting and analyzing tumor response to TKI-immunotherapy. An automatic liver tumor segmentation system, based on a two-stage 3D U-Net framework, delineates lesions by first segmenting the liver parenchyma and then precisely localizing the tumor. This approach effectively addresses the variability in clinical data and significantly reduces bias introduced by manual intervention. Thus, we developed a clinical model using only pre-treatment clinical information, a CNN model using only pre-treatment magnetic resonance imaging data, and an advanced multimodal CNN-Transformer model that fused imaging and clinical parameters using a training cohort (n = 181) and then validated them using an independent cohort (n = 30). In the validation cohort, the area under the curve (95% confidence interval) values were 0.720 (0.710-0.731), 0.695 (0.683-0.707), and 0.785 (0.760-0.810), respectively, indicating that the multimodal model significantly outperformed the single-modality baseline models across validations. Finally, single-cell sequencing with the surgical tumor specimens reveals tumor ecosystem diversity associated with treatment response, providing a preliminary biological validation for the prediction model. In summary, this multimodal model effectively integrates imaging and clinical features of HCC patients, has a superior performance in predicting tumor response to TKI-immunotherapy, and provides a reliable tool for optimizing personalized treatment strategies.

Organ transplantation is a definitive therapeutic option for patients with end-stage organ dysfunction and failure. Ischaemia-reperfusion (IR) injury is one of the leading causes of low graft utilisation as it significantly increases the risk of primary graft dysfunction and acute rejection following transplantation. This risk is particularly high for organs obtained from donors after circulatory death (DCD) when compared with the donors from brain death (DBD). IR injury exacerbates tissue damage via various mechanisms including the induction of regulated cell death. Regulated cell death and its consequences play critical roles in determining graft survival and function, thereby influencing the overall success of the transplant. Understanding the mechanisms underlying regulated cell death in IR injury is essential for developing therapeutic strategies to minimise tissue damage and improve clinical outcomes in organ transplantation. This review mainly discussed different types of regulated cell death and underlying mechanisms towards preventive cell death strategies in DBD and DCD organ transplantation in preclinical settings.