👤 Meng-Chuan Huang

Axis inhibition protein 1 (AXIN1), a scaffold protein interacting with various critical molecules, plays a vital role in determining cell fate. However, its impact on the antiviral innate immune response remains largely unknown. Here, we identify that AXIN1 acts as an effective regulator of antiviral innate immunity against both DNA and RNA virus infections. In the resting state, AXIN1 maintains the stability of the transcription factor interferon regulatory factor 3 (IRF3) by preventing p62-mediated autophagic degradation of IRF3. This is achieved by recruiting ubiquitin-specific peptidase 35 (USP35), which removes lysine (K) 48-linked ubiquitination at IRF3 K366. Upon virus infection, AXIN1 undergoes a phase separation triggered by phosphorylated TANK-binding kinase 1 (TBK1). This leads to increased phosphorylation of IRF3 and a boost in IFN-I production. Moreover, KYA1797K, a small molecule that binds to the AXIN1 RGS domain, enhances the AXIN1-IRF3 interaction and promotes the elimination of various highly pathogenic viruses. Clinically, patients with HBV-associated hepatocellular carcinoma (HCC) who show reduced AXIN1 expression in pericarcinoma tissues have low overall and disease-free survival rates, as well as higher HBV levels in their blood. Overall, our findings reveal how AXIN1 regulates IRF3 signaling and phase separation-mediated antiviral immune responses, underscoring the potential of the AXIN1 agonist KYA1797K as an effective antiviral agent. Show less

Hertwig's epithelial root sheath (HERS) interacts with dental apical mesenchyme and guides development of the tooth root, which is integral to the function of the whole tooth. However, the key genes in HERS essential for root development are understudied. Here, we show that Axin1, a scaffold protein that negatively regulates canonical Wnt signaling, is strongly expressed in the HERS. Axin1 ablation in the HERS of mice leads to defective root development, but in a manner independent of canonical Wnt signaling. Further studies reveal that Axin1 in the HERS negatively regulates the AKT1-mTORC1 pathway through binding to AKT1, leading to inhibition of ribosomal biogenesis and mRNA translation. Sonic hedgehog (Shh) protein, a morphogen essential for root development, is over-synthesized by upregulated mTORC1 activity upon Axin1 inactivation. Importantly, either haploinsufficiency of the mTORC1 subunit Rptor or pharmacological inhibition of Shh signaling can rescue the root defects in Axin1 mutant mice. Collectively, our data suggest that, independently of canonical Wnt signaling, Axin1 controls ribosomal biogenesis and selective mRNA translation programs via AKT1-mTORC1 signaling during tooth root development. Show less

Tripartite motif-containing protein 59 (TRIM59) is a biomarker for multiple tumors with crucial roles. However, the specific role of TRIM59 in germ cells remains largely unknown. Here, we investigated the effects and underlying regulatory mechanisms of TRIM59 on germ cells using the mouse spermatogonial cell line GC-1. Our results demonstrated that TRIM59 promoted proliferation and inhibited apoptosis of GC-1 cells. Mechanistically, TRIM59 maintained GC-1 cell behaviors through ubiquitination of AXIN1 to activate β-catenin signaling. Furthermore, activation of β-catenin signaling reversed the effects mediated by Show less

Wnt/β-catenin signaling is an attractive target for regenerative medicine. A powerful driver of stem cell activity and hence tissue regeneration, Wnt signaling can promote fibroblast proliferation and activation, leading to fibrosis, while prolonged Wnt signaling is potentially carcinogenic. Thus, to harness its therapeutic potential, the activation of Wnt signaling must be transient, reversible, and tissue specific. In the lung, Wnt signaling is essential for alveolar stem cell activity and alveolar regeneration, which is impaired in lung fibrosis. Activation of Wnt/β-catenin signaling in lung epithelium may have anti-fibrotic effects. Here, we used intratracheal adeno-associated virus 6 injection to selectively deliver CasRx into the lung epithelium, where it reversibly activates Wnt signaling by simultaneously degrading mRNAs encoding Axin1 and Axin2, negative regulators of Wnt/β-catenin signaling. Interestingly, CasRx-mediated Wnt activation specifically in lung epithelium not only promotes alveolar type II cell proliferation and alveolar regeneration but also inhibits lung fibrosis resulted from bleomycin-induced injury, relevant in both preventive and therapeutic settings. Our study offers an attractive strategy for treating pulmonary fibrosis, with general implications for regenerative medicine. Show less

Diabetic angiogenesis is closely associated with disabilities and death caused by diabetic microvascular complications. Advanced glycation end products (AGEs) are abnormally accumulated in diabetic patients and are a key pathogenic factor for diabetic angiogenesis. The present study focuses on understanding the mechanisms underlying diabetic angiogenesis and identifying therapeutic targets based on these mechanisms. In this study, AGE-induced angiogenesis serves as a model to investigate the mechanisms underlying diabetic angiogensis. Mouse aortic rings, matrigel plugs, and HUVECs or 293T cells were employed as research objects to explore this pathological process by using transcriptomics, gene promoter reporter assays, virtual screening and so on. Here, we found that AGEs activated Wnt/β-catenin signaling pathway and enhanced the β-catenin protein level by affecting the expression of β-catenin degradation-related genes, such as FZDs (Frizzled receptors), LRPs (LDL Receptor Related Proteins), and AXIN1. AGEs could also mediate β-catenin Y142 phosphorylation through VEGFR1 isoform5. These dual effects of AGEs elevated the nuclear translocation of β-catenin and sequentially induced the expression of KDR (Kinase Insert Domain Receptor) and HDAC9 (Histone Deacetylase 9) by POU5F1 and NANOG, respectively, thus mediating angiogenesis. Finally, through virtual screening, Bioymifi, an inhibitor that blocks VEGFR1 isoform5-β-catenin complex interaction and alleviates AGE-induced angiogenesis, was identified. Collectively, this study offers insight into the pathophysiological functions of β-catenin in diabetic angiogenesis. Show less

Lumbar spine and pelvic fractures(LPF) are combined with peripheral ligament injuries(PLI), frequently. It has been reported that the site of fracture injury is usually paralleled by the secretion of inflammatory proteins. This study aimed to investigate the causal relationship between 91 circulating inflammatory proteins and LPF and PLI by using a Two-sample Mendelian randomization (MR) analysis. Single nucleotide polymorphisms (SNPs) associated with 91 circulating inflammatory proteins, as exposures were selected from a large genome-wide association study (GWAS). The genetic variant data for LPF and PLI as outcomes from the FinnGen consortium. The inverse-variance-weighted (IVW) method was utilized as the main analysis for exposures and outcomes. In addition, the final results were reinforced by the methods of MR Egger, weighted median, simple mode, and weighted mode. The sensitivity analyses were used to validate the robustness of results and ensure the absence of heterogeneity and horizontal pleiotropy. MR-Steiger was used to assess whether the causal direction was correct to avoid reverse causality. This study has shown that Beta-nerve growth factor(Beta-NGF) and Interferon gamma(IFN-gamma) are both involved in the occurrence of LPF and PLI, and they are reducing the risk of occurrence(OR:0.800, 95%CI: 0.650-0.983; OR:0.723, 95%CI:0.568-0.920 and OR:0.812, 95%CI:0.703-0.937; OR:0.828, 95%CI:0.700-0.980). Similarly, Axin-1 and Sulfotransferase 1A1 (SULT-1A1) were causally associated with LPF(OR:0.687, 95%CI:0.501-0.942 and OR:1.178,95%CI:1.010-1.373). Furthermore, Interleukin-4(IL-4), Macrophage inflammatory protein 1a(MIP-1a), and STAM binding protein(STAM-BP) were causally associated with PLI(OR:1.236, 95% CI: 1.058-1.443; OR:1.107, 95% CI: 1.008-1.214 and OR:0.759, 95% CI: 0.617-0.933). The influence of heterogeneity and horizontal pleiotropy were further excluded by sensitivity analysis. This study provides new insights into the relationship between circulating inflammatory proteins and LPF and PLI, and may provide new clues for predicting this risk. Show less

The effectiveness of immune checkpoint inhibitor (ICI) therapy for hepatocellular carcinoma (HCC) is limited by treatment resistance. However, the mechanisms underlying immunotherapy resistance remain elusive. We aimed to identify the role of CT10 regulator of kinase-like (CRKL) in resistance to anti-PD-1 therapy in HCC. Gene expression in HCC specimens from 10 patients receiving anti-PD-1 therapy was identified by RNA-sequencing. A total of 404 HCC samples from tissue microarrays were analyzed by immunohistochemistry. Transgenic mice (Alb-Cre/Trp53 CRKL was identified as a candidate anti-PD-1-resistance gene using a pooled genetic screen. CRKL overexpression nullifies anti-PD-1 treatment efficacy by mobilizing tumor-associated neutrophils (TANs), which block the infiltration and function of CD8 Activation of the CRKL/β-catenin/VEGFα and CXCL1 axis is a critical obstacle to successful anti-PD-1 therapy. Therefore, CRKL inhibitors combined with anti-PD-1 could be useful for the treatment of HCC. Here, we found that CRKL was overexpressed in anti-PD-1-resistant hepatocellular carcinoma (HCC) and that CRKL upregulation promotes anti-PD-1 resistance in HCC. We identified that upregulation of the CRKL/β-catenin/VEGFα and CXCL1 axis contributes to anti-PD-1 tolerance by promoting infiltration of tumor-associated neutrophils. These findings support the strategy of bevacizumab-based immune checkpoint inhibitor combination therapy, and CRKL inhibitors combined with anti-PD-1 therapy may be developed for the treatment of HCC. Show less

Parkinson's disease (PD) is a progressive neurodegenerative disease whose etiology is attributed to development of Lewy bodies and degeneration of dopaminergic neurons in the substantia nigra (SN). Currently, there are no definitive diagnostic indicators for PD. In this study, we aimed to identify potential diagnostic biomarkers for PD and analyzed the impact of immune cell infiltrations on disease pathogenesis. The PD expression profile data for human SN tissue, GSE7621, GSE20141, GSE20159, GSE20163 and GSE20164 were downloaded from the Gene Expression Omnibus (GEO) database for use in the training model. After normalization and merging, we identified differentially expressed genes (DEGs) using the Robust rank aggregation (RRA) analysis. Simultaneously, DEGs after batch correction were identified. Gene interactions were determined through venn Diagram analysis. Functional analyses and protein-protein interaction (PPI) networks were used to the identify hub genes, which were visualized through Cytoscape. A Lasso Cox regression model was employed to identify the potential diagnostic genes. The GSE20292 dataset was used for validation. The proportion of infiltrating immune cells in the samples were determined via the CIBERSORT method. Sixty-two DEGs were screened in this study. They were found to be enriched in nerve conduction, dopamine (DA) metabolism, and DA biosynthesis Gene Ontology (GO) terms. The PPI network and Lasso Cox regression analysis revealed seven potential diagnostic genes, namely SLC18A2, TAC1, PCDH8, KIAA0319, PDE6H, AXIN1, and AGTR1, were subsequently validated in peripheral blood samples obtained from healthy control (HC) and PD patients, as well as in the GSE20292 dataset. The results revealed the exceptional sensitivity and specificity of these genes in PD diagnosis and monitoring. Moreover, PD patients exhibited a higher number of plasma cells, compared to HC individuals. The SLC18A2, TAC1, PCDH8, KIAA0319, PDE6H, AXIN1, and AGTR1 are potential diagnostic biomarkers for PD. Our findings also reveal the essential roles of immune cell infiltration in both disease onset and trajectory. Show less

Alzheimer's disease (AD), a leading neurodegenerative disorder, is closely associated with the accumulation of amyloid-beta (Aβ) peptides in the brain. The enzyme β-secretase (BACE1), pivotal in Aβ production, represents a promising therapeutic target for AD. While bioactive peptides derived from food protein hydrolysates have neuroprotective properties, their inhibitory effects on BACE1 remain largely unexplored. In this study, we evaluated the inhibitory potential of protein hydrolysates from gliadin, whey, and casein proteins prepared using bromelain, papain, and thermolysin. Through in vitro and cellular assays, bromelain-hydrolyzed gliadin (G-Bro) emerged as the most potent BACE1 inhibitor, with an IC Show less

Social isolation (SI) is a common phenomenon in the modern world, especially during the coronavirus disease 2019 pandemic, and causes lasting cognitive impairments and mental disorders. However, it is still unclear how SI alters molecules in the brain and induces behavioural dysfunctions. Here, we report that SI impairs cognitive function and induces depressive-like behaviours in C57BL/6 J mice, in addition to impairing synaptic plasticity and increasing the levels of APP cleavage-related enzymes, thereby promoting Aβ production. Moreover, we show that in APP/PS1 transgenic mice, SI accelerates pathological changes and behavioural deficits. Interestingly, downregulation of the expression of the BACE1 attenuates SI-induced Aβ toxicity and synaptic dysfunction. Furthermore, early intervention with BACE1 shRNA blocks SI-induced cognitive impairments. Together, our data strongly suggest that SI-induced upregulation of BACE1 expression mediates Aβ toxicity and induces behavioural deficits. Down-regulation of BACE1 may be a promising strategy for preventing SI-induced cognitive impairments. Show less

An in-situ nanozyme signal tag combined with a DNA-mediated universal antibody-oriented strategy was proposed to establish a high-performance immunosensing platform for Alzheimer's disease (AD)-related biomarker detection. Briefly, a Zr-based metal-organic framework (MOF) with peroxidase (POD)-like activity was synthesized to encapsulating the electroactive molecule methylene blue (MB), and subsequently modified with a layer of gold nanoparticles on its surface. This led to the creation of double POD-like activity nanozymes surrounding the MB molecule to form a nanozyme signal tag. A large number of hydroxyl radicals were generated by the nanozyme signal tag with the help of H Show less

Alzheimer's disease (AD) is a neurodegenerative disorder associated with age. A wealth of evidence indicates that the amyloid β (Aβ) aggregates result from dyshomeostasis between Aβ production and clearance, which plays a pivotal role in the pathogenesis of AD. Consequently, therapies targeting Aβ reduction represent a promising strategy for AD intervention. Tetramethylpyrazine nitrone (TBN) is a novel tetramethylpyrazine derivative with potential for the treatment of AD. Previously, we demonstrated that TBN markedly enhanced cognitive functions and decreased the levels of Aβ, APP, BACE 1, and hyperphosphorylated tau in 3×Tg-AD mice. However, the mechanism by which TBN inhibits Aβ deposition is still unclear. In this study, we employed APP/PS1 mice treated with TBN (60 mg/kg, ig, bid) for six months, and N2a/APP695swe cells treated with TBN (300 μM) to explore the mechanism of TBN in Aβ reduction. Our results indicate that TBN significantly alleviated cognitive impairment and reduced Aβ deposition in APP/PS1 mice. Further investigation of the underlying mechanisms revealed that TBN decreased the expression of APP and BACE1, activated the AMPK/mTOR/ULK1 autophagy pathway, inhibited the PI3K/AKT/mTOR/ULK1 autophagy pathway, and decreased the phosphorylation levels of JNK and ERK in APP/PS1 mice. Moreover, TBN was found to significantly reduce the mRNA levels of APP and BACE1, as well as those of SP1, CTCF, TGF-β, and NF-κB, transcription factors involved in regulating gene expression. Additionally, TBN was observed to decrease the level of Show less

With the rapid progress in deciphering the pathogenesis of Alzheimer's disease (AD), it has been widely accepted that the accumulation of misfolded amyloid β (Aβ) in the brain could cause the neurodegeneration in AD. Although much evidence demonstrates the neurotoxicity of Aβ, the role of Aβ in the nervous system are complex. However, more comprehensive studies are needed to understand the physiological effect of Aβ Show less

The fruits of Alpinia oxyphylla (Alpiniae Oxyphyllae Fructus, AOF) are one of the "Four Famous South Medicines" in China. In this study, beta-site amyloid protein precursor cleaving enzyme 1 (BACE1) was applied to explore the active components in AOF responsible for type 2 diabetes mellitus (T2DM)-related cognitive disorder. As a result, 24 compounds including three unreported ones (1, 3, 4) were isolated from AOF. Compound 1 is an unusual carbon‑carbon linked diarylheptanoid dimer, and compound 4 is the first case of 3,4-seco-eudesmane sesquiterpenoid with a 5/6-bicyclic skeleton. Four diarylheptanoids (3, 5-7), one flavonoid (9) and two sesquiterpenoids (14 and 20) showed BACE1 inhibitory activity, of which the most active 6 was revealed to be a non-competitive and anti-competitive mixed inhibitor. Docking simulation suggested that OH-4' of 6 played important roles in maintaining activity by forming hydrogen bonds with Ser36 and Ile126 residues. Compounds 3, 5, 9 and 20 displayed neuroprotective effects against amyloid β (Aβ)-induced damage in BV2 cells. Mechanism study revealed that compounds 5 and 20 downregulated the expression of BACE1 and upregulated the expression of Lamp2 to exert effects. Thus, the characteristic diarylheptanoids and sesquiterpenoids in AOF had the efficacy to alleviate T2DM-related cognitive disorder by inhibiting BACE1 activity and reversing Aβ-induced neuronal damage. Show less

Olfactory dysfunction is increasingly recognized as an early indicator of Alzheimer's disease (AD). Aberrations in GABAergic function and the excitatory/inhibitory (E/I) balance within the olfactory bulb (OB) have been implicated in olfactory impairment during the initial stages of AD. While the neuregulin 1 (NRG1)/ErbB4 signaling pathway is known to regulate GABAergic transmission in the brain and is associated with various neuropsychiatric disorders, its specific role in early AD-related olfactory impairment remains incompletely understood. This study demonstrated that olfactory dysfunction preceded cognitive decline in young adult APP/PS1 mice and was characterized by reduced levels of NRG1 and ErbB4 in the OB. Further investigation revealed that deletion of ErbB4 in parvalbumin interneurons reduced GABAergic transmission and increased hyperexcitability in mitral and tufted cells (M/Ts) in the OB, thereby accelerating olfactory dysfunction in young adult APP/PS1 mice. Additionally, ErbB4 deficiency was associated with increased accumulation of Aβ and BACE1-mediated cleavage of APP, along with enhanced CDK5 signaling in the OB. NRG1 infusion into the OB was found to enhance GABAergic transmission in M/Ts and alleviate olfactory dysfunction in young adult APP/PS1 mice. These findings underscore the critical role of NRG1/ErbB4 signaling in regulating GABAergic transmission and E/I balance within the OB, contributing to olfactory impairment in young adult APP/PS1 mice, and provide novel insights for early intervention strategies in AD. This work has shown that ErbB4 deficiency increased the burden of Aβ, impaired GABAergic transmission, and disrupted the E/I balance of mitral and tufted cells (M/Ts) in the OB, ultimately resulting in olfactory dysfunction in young adult APP/PS1 mice. NRG1 could enhance GABAergic transmission, rescue E/I imbalance in M/Ts, and alleviate olfactory dysfunction in young adult APP/PS1 mice. OB: olfactory bulb, E/I: excitation/inhibition, Pr: probability of release, PV: parvalbumin interneurons, Aβ: β-amyloid, GABA: gamma-aminobutyric acid. Show less

CLEC4G, a glycan-binding receptor, has previously been demonstrated to inhibit Aβ generation, yet its brain localization and functions in Alzheimer's disease (AD) are not clear. We explored the localization, function, and regulatory network of CLEC4G via experiments and analysis of RNA-seq databases. CLEC4G transcripts and proteins were identified in brain tissues, with the highest expression observed in neurons. Notably, AD was associated with reduced levels of CLEC4G transcripts. Bioinformatic analyses revealed interactions between CLEC4G and relevant genes such as BACE1, NPC1, PILRA, TYROBP, MGAT1, and MGAT3, all displaying a negative correlation trend. We further identified the upstream transcriptional regulators NR2F6 and XRCC4 for CLEC4G and confirmed a decrease in CLEC4G expression in APP/PS1 transgenic mice. This study highlights the role of CLEC4G in protecting against AD progression and the significance of CLEC4G for AD research and management. Show less

Alzheimer's disease is the most common form of dementia and is characterized by cognitive impairment. The disruption of autophagosome-lysosome function has been linked to the pathogenesis of Alzheimer's disease. Tris (1,3-dichloro-2-propyl) phosphate (TDCIPP) is a widely used organophosphorus flame retardant that has the potential to cause neuronal damage. We found that TDCIPP significantly increased the expression of β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1), presenilin-1 (PS1) and Aβ42. Proteomic studies with TMT labeling revealed changes in the profiles of N2a-APPswe cells after exposure to TDCIPP. Proteomic and bioinformatics analyses revealed that lysosomal proteins were dysregulated in N2a-APPswe cells after treatment with TDCIPP. The LC3, P62, CTSD, and LAMP1 levels were increased after TDCIPP exposure, and dysregulated protein expression was validated by Western blotting. The exposure to TDCIPP led to the accumulation of autophagosomes, and this phenomenon was enhanced in the presence of chloroquine (CQ). Our results revealed for the first time that TDCIPP could be a potential environmental risk factor for AD development. The inhibition of autophagosome-lysosome fusion may have a significant impact on the generation of Aβ1-42 in response to TDCIPP. Show less

Alzheimer's disease (AD) is a significant global health concern, and it is crucial that we find effective methods to prevent or slow down AD progression. Recent studies have highlighted the essential role of blood vessels in clearing Aβ, a protein that contributes to AD. Scientists are exploring blood biomarkers as a potential tool for future AD diagnosis. One promising method that may help prevent AD is remote ischemic conditioning (RIC). RIC involves using sub-lethal ischemic-reperfusion cycles on limbs. However, a comprehensive understanding of how RIC can prevent AD and its long-term effectiveness is still lacking. Further research is essential to fully comprehend the potential benefits of RIC in preventing AD. Female wild-type (WT) and APP/PS1 transgenic rats, aged 12 months, underwent ovariectomy and were subsequently assigned to WT, APP/PS1, and APP/PS1 + RIC groups. RIC was conducted five times a week for 4 weeks. The rats' depressive and cognitive behaviors were evaluated using force swimming, open-field tests, novel objective recognition, elevated plus maze, and Barnes maze tests. Evaluation of the neurovascular unit (NVU), synapses, vasculature, astrocytes, and microglia was conducted using immunofluorescence staining (IF), Western blot (WB), and transmission electron microscopy (TEM). Additionally, the cerebro-vasculature was examined using micro-CT, and cerebral blood flow (CBF) was measured using Speckle Doppler. Blood-brain barrier (BBB) permeability was determined by measuring the Evans blue leakage. Finally, Aβ levels in the rat frontal cortex were measured using WB, ELISA, or IF staining. RIC enhanced memory-related protein expression and rescued depressive-like behavior and cognitive decline in APP/PS1 transgenic rats. Additionally, the intervention protected NVU in the rat frontal cortex, as evidenced by (1) increased expression of TJ (tight junction) proteins, pericyte marker PDGFRβ, and glucose transporter 1 (GLUT1), as well as decreased VCAM1; (2) mitigation of ultrastructure impairment in neuron, cerebral vascular, and astrocyte; (3) upregulation of A2 astrocyte phenotype markers and downregulation of A1 phenotype markers, indicating a shift toward a healthier phenotype. Correspondingly, RIC intervention alleviated neuroinflammation, as evidenced by the decreased Iba1 level, a microglia marker. Meanwhile, RIC intervention elevated CBF in frontal cortex of the rats. Notably, RIC intervention effectively suppressed Aβ toxicity, as demonstrated by the enhancement of α-secretase and attenuation of β-secretase (BACE1) and γ- secretase and Aβ1-42 and Aβ1-40 levels as well. Chronic RIC intervention exerts vascular and neuroprotective roles, suggesting that RIC could be a promising therapeutic strategy targeting the BBB and NVU during AD development. Show less

A series of novel hybrid compounds were designed, synthesized, and utilized as multi-target drugs to treat Alzheimer's disease (AD) by connecting capsaicin and tacrine moieties. The biological assays indicated that most of these compounds demonstrated strong inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities with IC Show less

Alzheimer's disease (AD) is a highly heritable disease. The morphological changes of cortical cortex (such as, cortical thickness and surface area) in AD always accompany by the change of the functional connectivity to other brain regions and influence the short- and long-range brain network connections, causing functional deficits of AD. In this study, the first hypothesis is that genetic variations might affect morphology-based brain networks, leading to functional deficits; the second hypothesis is that protein-protein interaction (PPI) between the candidate proteins and known interacting proteins to AD might exist and influence AD. 600 470 variants and structural magnetic resonance imaging scans from 175 AD patients and 214 healthy controls were obtained from the Alzheimer's Disease Neuroimaging Initiative-1 database. A co-sparse reduced-rank regression model was fit to study the relationship between non-synonymous mutations and morphology-based brain networks. After that, PPIs between selected genes and BACE1, an enzyme that was known to be related to AD, are explored by using molecular dynamics (MD) simulation and co-immunoprecipitation (Co-IP) experiments. Eight genes affecting morphology-based brain networks were identified. The results of MD simulation showed that the PPI between TGM4 and BACE1 was the strongest among them and its interaction was verified by Co-IP. Hence, gene variations influence morphology-based brain networks in AD, leading to functional deficits. This finding, validated by MD simulation and Co-IP, suggests that the effect is robust. Show less

Branched chain α-keto acid dehydrogenase kinase (BCKDK) is a key enzyme involved in the metabolism of branched-chain amino acids (BCAAs). Its potential as a therapeutic target and prognostic factor for a variety of cancers has been widely reported. In this study, we investigated the expression of BCKDK in clinical glioma samples and found that BCKDK was significantly overexpressed in glioblastoma (GBM) and was associated with its poor prognosis. We further found that BCKDK is phosphorylated by tyrosine protein kinase Fyn at Y151, which increases its catalytic activity and stability, and demonstrate through Show less

Altered branched chain amino acids (BCAAs), including leucine, isoleucine, and valine, are frequently observed in patients with advanced cancer. We evaluated the efficacy of chimeric antigen receptor (CAR) T cell-mediated cancer cell lysis potential in the immune microenvironment of BCAA supplementation and deletion. BCAA supplementation increased cancer cell killing percentage, while accelerating BCAA catabolism and decreasing BCAA transporter decreased cancer cell lysis efficacy. We thus designed BCKDK engineering CAR T cells for the reprogramming of BCAA metabolism in the tumor microenvironment based on the genotype and phenotype modification. BCKDK overexpression (OE) in CAR-T cells significantly improved cancer cell lysis, while BCKDK knockout (KO) resulted in inferior lysis potential. In an in vivo experiment, BCKDK-OE CAR-T cell treatment significantly prolonged the survival of mice bearing NALM6-GL cancer cells, with the differentiation of central memory cells and an increasing proportion of CAR-T cells in the peripheral circulation. BCKDK-KO CAR-T cell treatment resulted in shorter survival and a decreasing percentage of CAR-T cells in the peripheral circulation. In conclusion, BCKDK-engineered CAR-T cells exert a distinct phenotype for superior anticancer efficiency. Show less

Branched chain amino acids (BCAAs) are essential amino acids and important nutrient signals for energy and protein supplementation. The study uses muscle-specific branched-chain α-keto acid dehydrogenase kinase (Bckdk) conditional knockout (cKO) mice to reveal the contribution of BCAA metabolic dysfunction to muscle wasting. Muscle-specific Bckdk-cKO mice are generated through crossbreeding of Bckdk Dysfunctional BCAA metabolism contributes to the inhibition of protein synthesis and increases protein degradation in the cancer cachexia model of muscle-specific Bckdk-cKO mice bearing LLC tumors. The reprogramming of BCAA catabolism exerts therapeutic effects by stimulating protein synthesis and inhibiting protein degradation in skeletal muscle. Show less

Metabolic reprogramming of vascular smooth muscle cell (VSMC) plays a critical role in the pathogenesis of thoracic aortic dissection (TAD). Previous researches have mainly focused on dysregulation of fatty acid or glucose metabolism, while the impact of amino acids catabolic disorder in VSMCs during the development of TAD remains elusive. Here, we identified branched-chain amino acid (BCAA) catabolic defect as a metabolic hallmark of TAD. The bioinformatics analysis and data from human aorta revealed impaired BCAA catabolism in TAD individuals. This was accompanied by upregulated branched-chain α-ketoacid dehydrogenase kinase (BCKDK) expression and BCKD E1 subunit alpha (BCKDHA) phosphorylation, enhanced vascular inflammation, and hyperactivation of mTOR signaling. Further in vivo experiments demonstrated that inhibition of BCKDK with BT2 (a BCKDK allosteric inhibitor) treatment dephosphorylated BCKDHA and re-activated BCAA catabolism, attenuated VSMCs phenotypic switching, alleviated aortic remodeling, mitochondrial reactive oxygen species (ROS) damage and vascular inflammation. Additionally, the beneficial actions of BT2 were validated in a TNF-α challenged murine VSMC cell line. Meanwhile, rapamycin conferred similar beneficial effects against VSMC phenotypic switching, cellular ROS damage as well as inflammatory response. However, co-treatment with MHY1485 (a classic mTOR activator) reversed the beneficial effects of BT2 by reactivating mTOR signaling. Taken together, the in vivo and in vitro evidence showed that impairment of BCAA catabolism resulted in aortic accumulation of BCAA and further caused VSMC phenotypic switching, mitochondrial ROS damage and inflammatory response via mTOR hyperactivation. BCKDK and mTOR signaling may serve as the potential drug targets for the prevention and treatment of TAD. Show less

Chromobox Homolog 1 (CBX1) plays a crucial role in the pathogenesis of numerous diseases, including the evolution and advancement of diverse cancers. The role of CBX1 in pan-cancer and its mechanism in hepatocellular carcinoma (HCC), however, remains to be further investigated. Bioinformatics approaches were harnessed to scrutinize CBX1's expression profile, its association with tumor staging, and its potential impact on patient outcomes across various cancers. Single-cell RNA sequencing data facilitated the investigation of CBX1 expression patterns at the individual cell level. The CBX1 expression levels in HCC and adjacent non-tumor tissues were quantified through Real-Time Polymerase Chain Reaction (RT-PCR), Western Blotting (WB), and Immunohistochemical analyses. A tissue microarray was employed to explore the relationship between CBX1 levels, patient prognosis, and clinicopathological characteristics in HCC. Various in vitro assays-including CCK-8, colony formation, Transwell invasion, and scratch tests-were conducted to assess the proliferative and motility properties of HCC cells upon modulation of CBX1 expression. Moreover, the functional impact of CBX1 on HCC was further discerned through xenograft studies in nude mice. CBX1 was found to be upregulated in most cancer forms, with heightened expression correlating with adverse patient prognoses. Within the context of HCC, elevated levels of CBX1 were consistently indicative of poorer clinical outcomes. Suppression of CBX1 through knockdown methodologies markedly diminished HCC cell proliferation, invasive capabilities, migratory activity, Epithelial-mesenchymal transition (EMT) processes, and resistance to Tyrosine kinase inhibitors (TKIs). Contrastingly, CBX1 augmentation facilitated the opposite effects. Subsequent investigative efforts revealed CBX1 to be a promoter of EMT and a contributor to increased TKI resistance within HCC cells, mediated via the IGF-1R/AKT/SNAIL signaling axis. The oncogenic activities of CBX1 proved to be attenuable either by AKT pathway inhibition or by targeted silencing of IGF-1R. The broad overexpression of CBX1 in pan-cancer and specifically in HCC positions it as a putative oncogenic entity. It is implicated in forwarding HCC progression and exacerbating TKI resistance through its interaction with the IGF-1R/AKT/SNAIL signaling cascade. Show less

The Chromobox (CBX) family proteins are crucial elements of the epigenetic regulatory machinery and play a significant role in the development and advancement of cancer. Nevertheless, there is limited understanding regarding the role of CBXs in development or progression of prostate cancer (PCa). Our objective is to develop a unique prognostic model associated with CBXs to improve the accuracy of predicting outcomes of patients with PCa. Data from TCGA and GEO databases were analyzed to assess differential expression, prognostic value, gene pathway enrichment, and immune cell infiltration. COX regression analysis was utilized to identify the independent prognostic factors that impact disease-free survival (DFS). The expression of CBX2 and FOXP3 CBX2, CBX3, CBX4, and CBX8 were upregulated, while CBX6 and CBX7 were downregulated in PCa tissues. CBXs expression varied by stage and grade. Elevated expression of CBX1, CBX2, CBX3, CBX4 and CBX8 is correlated with poor outcome. CBX2 expression, T stage, and Gleason score were independent prognostic factors. The expression level of CBX2 in PCa tissues was significantly higher than that in adjacent normal tissues. More Treg infiltration was observed in the group with high CBX2 expression. CBX2 expression affected PCa cell growth, migration, and invasion. CBX2 is involved in the development and advancement of PCa, suggesting its potential as a reliable prognostic indicator for PCa patients. Show less