Inhibition of CXXC5 function rescues Alzheimer's disease phenotypes by restoring Wnt/β-catenin signaling pathway

CXXC5 is a ubiquitinated protein and is degraded by the ubiquitin-proteasome pathway

CXXC5, as a member of the zinc-finger CXXC family proteins, interacts with unmodified CpG dinucleotides to modulate the expression of genes involved in cellular proliferation, differentiation, and death in physiology and pathophysiology. Various signaling pathways, including mitogenic 17β-estradiol (E2), contribute to the expression and synthesis of CXXC5. However, how signaling pathways modulate protein levels of CXXC5 in cells is largely unknown. We previously reported that some key regulators, including retinoblastoma 1 and E74-like ETS transcription factor 1, of the G1 to S phase transitions are involved in the expression of CXXC5 in estrogen-responsive MCF-7 cells, derived from a breast adenocarcinoma. We, therefore, predict that the synthesis of CXXC5 is regulated in a cell cycle-dependent manner. We report here that although E2 in synchronized MCF-7 cells augments both transcription and synthesis of CXXC5 in the G1 phase, CXXC5 protein levels are primarily mediated by ubiquitination independently of cell cycle phases. Utilizing the bioUbiquitination approach, which is based on cellular biotinylation of ubiquitin, in HEK293FT cells derived from immortalized human embryonic kidney cells, followed by sequential immunoprecipitation coupled mass spectrometry analyses, we identified ubiquitinated lysine residues of CXXC5. We show in both MCF-7 and HEK293FT cells that the ubiquitinated lysine residues contribute to the degradation of CXXC5 through the ubiquitin-proteasome pathway.

Wnt signaling pathways in biology and disease: mechanisms and therapeutic advances

The Wnt signaling pathway is critically involved in orchestrating cellular functions such as proliferation, migration, survival, and cell fate determination during development. Given its pivotal role in cellular communication, aberrant Wnt signaling has been extensively linked to the pathogenesis of various diseases. This review offers an in-depth analysis of the Wnt pathway, detailing its signal transduction mechanisms and principal components. Furthermore, the complex network of interactions between Wnt cascades and other key signaling pathways, such as Notch, Hedgehog, TGF-β, FGF, and NF-κB, is explored. Genetic mutations affecting the Wnt pathway play a pivotal role in disease progression, with particular emphasis on Wnt signaling's involvement in cancer stem cell biology and the tumor microenvironment. Additionally, this review underscores the diverse mechanisms through which Wnt signaling contributes to diseases such as cardiovascular conditions, neurodegenerative disorders, metabolic syndromes, autoimmune diseases, and cancer. Finally, a comprehensive overview of the therapeutic progress targeting Wnt signaling was given, and the latest progress in disease treatment targeting key components of the Wnt signaling pathway was summarized in detail, including Wnt ligands/receptors, β-catenin destruction complexes, and β-catenin/TCF transcription complexes. The development of small molecule inhibitors, monoclonal antibodies, and combination therapy strategies was emphasized, while the current potential therapeutic challenges were summarized. This aims to enhance the current understanding of this key pathway.

Construction and evaluation of a diagnostic model for Alzheimer's disease based on mitophagy-related genes

Alzheimer's disease (AD) is the most common cause of dementia. Mitophagy fulfills crucial functions in neurodegenerative disorders and neuronal survival but the relationship between mitophagy and AD is unclear. Mitophagy correlation scores between AD samples and control samples were calculated using single-sample GSEA (ssGSEA) based on two datasets from gene expression omnibus (GEO) database. Mitophagy-related genes (MRGs) and differentially expressed genes (DEGs) in AD screened by WGCNA and "limma" package were intersected to take common genes. These overlapping genes were further compressed and used for diagnostic modeling by adopting the recursive feature elimination (RFE) and LASSO analysis. The reliability of the diagnostic model was verified based on the receiver operating characteristic (ROC) curve. Then, a transcription factor (TF)-mRNA regulatory network of these key genes was established. Lastly, ssGSEA was employed to examine the relationship between the identified genes and cellular pathways and immune cell infiltration. AD samples had notably lower mitophagy correlation scores than control samples. A total of 12 MRGs in the module with the greatest mitophagy connection with AD patients were identified. Functional enrichment analysis revealed that the DEGs were significantly enriched in synaptic function-related pathways. Based on GSE122063, a diagnostic prediction model was created and validated using two mitophagy-related genes (YWHAZ and NDE1), showing an area under ROC curve (AUC) greater than 0.7. This confirmed that the diagnostic model had a high predictive value. The TF-mRNA network showed that four TFs, namely, FOXC1, FOXL1, HOXA5 and GATA2, were regulated by both YWHAZ and NDE1 genes. Immune infiltration analysis revealed that NDE1 promoted the infiltration of most immune cells, while YWHAZ mainly inhibited the infiltration of most immune cells. The current findings improved our understanding of mitophagy in AD, contributing to future research and treatment development in AD.

Unlocking Hope: Therapeutic Advances and Approaches in Modulating the Wnt Pathway for Neurodegenerative Diseases

Neurodegenerative diseases (NDs) are conditions characterized by sensory, motor, and cognitive impairments due to alterations in the structure and function of neurons in the central nervous system (CNS). Despite their widespread occurrence, the exact causes of NDs remain largely elusive, and existing treatments fall short in efficacy. The Wnt signaling pathway is an emerging molecular pathway that has been linked to the development and progression of various NDs. Wnt signaling governs numerous cellular processes, such as survival, polarity, proliferation, differentiation, migration, and fate specification, via a complex network of proteins. In the adult CNS, Wnt signaling regulates synaptic transmission, plasticity, memory formation, neurogenesis, neuroprotection, and neuroinflammation, all essential for maintaining neuronal function and integrity. Dysregulation of both canonical and non-canonical Wnt signaling pathways contributes to neurodegeneration through various mechanisms, such as amyloid-β accumulation, tau protein hyperphosphorylation, dopaminergic neuron degeneration, and synaptic dysfunction, prompting investigations into Wnt modulation as a therapeutic target to restore neuronal function and prevent or delay neurodegenerative processes. Modulating Wnt signaling has the potential to restore neuronal function and impede or postpone neurodegenerative processes, offering a therapeutic approach for targeting NDs. In this article, the current knowledge about how Wnt signaling works in Alzheimer's disease and Parkinson's disease is discussed. Our study aims to explore the molecular mechanisms, recent discoveries, and challenges involved in developing Wnt-based therapies.

Signal integrator function of CXXC5 in Cancer

CXXC type zinc finger protein 5 (CXXC5) is a member of the ZF-CXXC family and plays a pivotal role in signal integration and information transfer within cell signaling network. CXXC5 acts as a regulator in various physiological processes, and abnormalities in its protein structure or function have been linked to multiple pathological processes. In this article, we correspondingly describe the composition of the ZF-CXXC family, emphatically introducing the features of the CXXC5 gene and protein, review the role of CXXC5 in cellular signaling networks, the physiological and pathological processes associated with CXXC5 dysregulation, and particularly focus on the correlation between CXXC5 and cancers. Finally, we summarize the current therapies targeting CXXC5 and their potential applications, and discuss the intriguing findings from current studies, and the opportunities and challenges in future.

Harmony of Wnt pathway in Alzheimer's: Navigating the multidimensional progression from preclinical to clinical stages

The Wnt pathway stands out as a pivotal signal transduction pathway, operating through two distinct modes of signaling: the canonical/β-catenin pathway and the non-canonical pathway. Among these, the canonical pathway assumes a paramount role in various physiological and pathological processes within the human body. Particularly in the brain, Wnt exhibits involvement in fundamental physiological events including neuronal differentiation/survival, axonogenesis, neural stem cell regulation, synaptic plasticity, and cell cycle modulation. Notably, scientific evidence underscores the critical role of the Wnt pathway in the pathogenesis of Alzheimer's disease (AD), correlating with its involvement in key pathological features such as tau tangles, Amyloid-β plaques, synaptic dysfunction, oxidative stress, mitochondrial dysfunction, cognitive impairments, and disruption of the blood-brain barrier integrity. This review aims to comprehensively explore the involvement and significance of Wnt signaling in Alzheimer's. Furthermore, it delves into recent advancements in research on Wnt signaling, spanning from preclinical investigations to clinical trials.

CXXC5 drove inflammation and ovarian cancer proliferation via transcriptional activation of ZNF143 and EGR1

CXXC5, a zinc-finger protein, is known for its role in epigenetic regulation via binding to unmethylated CpG islands in gene promoters. As a transcription factor and epigenetic regulator, CXXC5 modulates various signaling processes and acts as a key coordinator. Altered expression or activity of CXXC5 has been linked to various pathological conditions, including tumorigenesis. Despite its known role in cancer, CXXC5's function and mechanism in ovarian cancer are unclear. We analyzed multiple public databases and found that CXXC5 is highly expressed in ovarian cancer, with high expression correlating with poor patient prognosis. We show that CXXC5 expression is regulated by oxygen concentration and is a direct target of HIF1A. CXXC5 is critical for maintaining the proliferative potential of ovarian cancer cells, with knockdown decreasing and overexpression increasing cell proliferation. Loss of CXXC5 led to inactivation of multiple inflammatory signaling pathways, while overexpression activated these pathways. Through in vitro and in vivo experiments, we confirmed ZNF143 and EGR1 as downstream transcription factors of CXXC5, mediating its proliferative potential in ovarian cancer. Our findings suggest that the CXXC5-ZNF143/EGR1 axis forms a network driving ovarian cell proliferation and tumorigenesis, and highlight CXXC5 as a potential therapeutic target for ovarian cancer treatment.