Cellular & Molecular Biology Letters最新文献

Immune evasion is one of the hallmarks of cancers, including glioblastoma, the most aggressive form of primary brain tumors. Multiple mechanisms are employed by tumor cells and its microenvironment to evade immune detection and foster tumor growth and progression. The secretion of immunosuppressive molecules such as transforming growth factor-β (TGF-β) and interleukin-10 (IL-10), the expression of checkpoint proteins such programmed death-ligand 1 (PD-L1), and the recruitment of T-regulatory cells (Tregs) and myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment (TME) leads to suppressed immune cell activity, favoring unchecked tumor growth. The FAT atypical cadherin 1 (FAT1) has shown context/tissue-dependent effects in cancers of different tissue origins, with either oncogenic or tumor suppressor roles. Our laboratory has reported FAT1 to have an oncogenic function in glioblastoma. In addition, FAT1 promotes an immunosuppressive microenvironment in glioblastoma, reducing T-cell and monocyte infiltration while increasing immunosuppressive cells such as MDSCs. It also upregulates pro-inflammatory mediators [cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β), and interleukin-6 (IL-6)], fostering tumor-promoting signaling. This dual role in immune evasion and pro-tumorigenic inflammatory processes makes FAT1 a key driver of glioblastoma progression. This highlights the potential of FAT1 as a compelling therapeutic target. This article provides a concise overview of immune tolerance mechanisms in glioblastoma, and the crucial role of FAT1 in promoting immune tolerance and tumor advancement. In addition, this review highlights currently available immunotherapies in clinical use or undergoing trials, and the potential of FAT1 as a promising target for combinatorial therapeutic interventions.

Background: Obtaining human neurons and astrocytes for in vitro studies presents a significant challenge owing to the complexity of replicating their development and functionality outside the human brain. The Ntera-2 cell line is a valuable source of human neurons and astrocytes in neuroscience research. However, differentiating Ntera-2 cells into neurons and astrocytes with all-trans retinoic acid is complicated by the lack of reliable markers to monitor differentiation stages effectively. This study aimed to characterize neuron-enriched and pure astrocyte cultures at two maturation stages and to compare these with the original Ntera-2 cells. Ntera-2 cells and NT2 cells are used interchangeably in this publication.

Methods: Using an advanced proteomic approach, we assessed the protein composition and abundance of neuron and astrocyte co-cultures and discovered that the astrocytic protein profile in co-culture with neurons was more representative compared with that in pure astrocyte cultures. Additionally, electrophysiological studies were conducted to investigate the best astrocyte content for neuronal functionality.

Results: Mass spectrometry-based analysis provided insights into over 9000 proteins, covering well-known protein markers, proteins unique to specific cell types, and differentially expressed proteins. Notably, differences in transcription factors, regulatory proteins, intermediate filaments, and proteins unique to early and mature astrocytes highlighted the distinct maturation, activation, and functional profiles of the various cells. These findings offer a straightforward tool for characterization and monitoring the differentiation process. Three weeks of maturation in pure culture yielded immature astrocytes; however, extending the maturation period to 6 weeks significantly altered the composition of the cellular proteome, indicating increased astrocyte maturity. Studies revealed a broader repertoire of astrocytic proteins in co-culture with neurons. Meanwhile, electrophysiological analyses demonstrated that a high content of astrocytes is essential for neuronal functional maturity.

Conclusions: Astrocyte-neuron co-cultures offer a more accurate model of neural tissue than pure cultures, highlighting the complexity of cell maturation and providing insights for improving in vitro modeling of human neural development.

There is a significant gap in multi-omics studies on keloids, especially concerning the interaction between fibroblasts and super-enhancers (SEs). Identifying novel biomarkers within the epigenetic landscape could greatly improve keloid management. In this study, we investigated gene expression at both transcriptional and translational levels to identify potential biomarkers and employed CUT&Tag technology to validate SE-associated genes and upstream transcription factors (TFs). Through integrated analyses of transcriptomics and proteomics, 10 hub genes that associated with ECM, immune, and metabolic pathways were found. Given the crucial role of fibroblasts in keloid pathogenesis, we further identified five SE-associated genes (SERPINH1 SE, MMP14 SE, COL5A1 SE, COL16A1 SE, and SPARC SE) that exhibit characteristic upregulation in keloids. Analysis of upstream TFs and core transcription regulatory circuitry (CRC) revealed potential master TFs (FOSL2, BACH2, and FOXP1), with FOXP1 emerging as the core TF likely driving pro-fibrotic development through its anti-senescence function. In summary, we anticipate that the outcomes of the integrative omics analysis will facilitate further investigation into the underlying molecular mechanisms of keloid formation and lead to novel strategies for its prevention and management. Specifically inhibiting the anti-senescence function of FOXP1 brings new promise for the treatment of fibrosis-related diseases.

Abnormal climate change seriously endangers the safety of outdoor work and life, often causing hypothermia-induced coma or death. As the underlying mechanism has not been fully elucidated, a targeted treatment for hypothermia-triggered neuronal injury and forensic pathology indicators of fatal hypothermia are lacking. Herein, we aimed to explore hypothermia-induced changes in gene expression and metabolite profiles of cerebral cortical tissues to elucidate the mechanism of hypothermia-promoted necroptosis of cerebral cortical neurons. Flow cytometry and fluoro-jade C staining showed that low temperature caused necroptosis of cerebral cortical neurons. Transcriptomics identified 244 differential genes between hypothermia-exposed cortical tissue and control tissue. These genes were enriched in tumor necrosis factor (TNF)-α and nuclear factor (NF)-kappa B signaling pathways, as revealed by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Broadly targeted metabolomics identified 49 differential metabolites with significant differences. N-alpha-acetyl-L-arginine, argininosuccinic acid, glutaric acid, and other ornithine cycle-associated metabolites were significantly reduced in the hypothermia-exposed cortical tissue, driving fumaric acid reduction in the tricarboxylic acid (TCA) cycle. In addition, KEGG enrichment analysis showed significant changes in the TCA cycle pathway. A combined transcriptomic and metabolomic analysis uncovered that hypothermia induced oxidative stress through NF-κB activation, caused mitochondrial damage, impaired the ornithine cycle, and, ultimately, induced neuronal necroptosis. Pharmacological inhibition of NF-κB by the SC75741 inhibitor effectively ameliorated hypothermia-triggered necroptosis. In conclusion, our results suggest that the NF-κB transcription factor is a potential marker of hypothermia-induced neuronal necroptosis in the mouse cerebral cortex. In addition, our findings indicate the mechanism of necroptosis in cerebral cortical neurons caused by low temperature, which is beneficial for our understanding of hypothermia-induced coma and death.

Background: It is estimated that over 85% of human transcripts are non-coding RNAs, which play an important role in the regulation of numerous biological processes and are closely associated with the development of human cancers. Nevertheless, the functions of the vast majority of non-coding RNAs are yet to be clearly elucidated.

Methods: Long non-coding RNA (lncRNA) LINC02320 was screened out by RNA-sequencing using paired CRC samples. The level of LINC02320 in colorectal cancer (CRC) tissues and cell lines was validated by qRT-PCR and in situ hybridization (ISH). CCK8, colony formation, transwell, wound healing and xenograft experiments were carried out to investigate the function of LINC02320. Antisense oligonucleotide (ASO) was used to target LINC02320. Mass spectrometry, pull-down, western blot and CUT&Tag assays were conducted to investigate the molecular mechanism of LINC02320, ILF2, GRB7, MAPK and FOS.

Results: LINC02320 was highly expressed in metastatic colorectal cancer (CRC) tissues based on RNA-sequencing. ISH staining using tissue microarray (TMA) indicated that LINC02320 is associated with the clinical stage and survival rate of patients with CRC. The results of loss-of-function and gain-of-function experiments demonstrated that LINC02320 facilitates cancer cell proliferation and metastasis in vitro and in vivo while simultaneously inhibiting apoptosis. LINC02320 is present in both the nucleus and cytoplasm, with a nuclear function. Mechanistically, LINC02320 recruits the transcriptional regulator ILF2 to the GRB7 promoter, thereby initiating its transcription. GRB7 then activates the mitogen-activated protein kinase (MAPK) signaling pathway, which contributes to CRC progression and leads to increased phosphorylation of the transcription factor FOS. Phosphorylated FOS directly promotes LINC02320 transcription, forming a positive feedback loop and amplifies this pro-cancer signal. Notably, LINC02320-targeted ASO therapy significantly blocked tumor growth in vivo.

Conclusion: In summary, our findings demonstrate the essential role of LINC02320 involved in CRC progression, which provides novel insights into the importance of lncRNA as a therapeutic target in cancer treatment.

Yes-associated protein (YAP) and its paralog, transcriptional coactivator with PDZ-binding motif (TAZ), are critical effectors of the Hippo pathway, as well as other biochemical and biophysical signals. Through their interaction with DNA-binding partners, YAP/TAZ can modulate the transcription of many genes critical for organ size regulation and tissue homeostasis maintenance. Aberrant expression or activation of YAP/TAZ is implicated in the pathogenesis of many cancers and noncancerous diseases. Notably, their functional outputs demonstrate remarkable diversity, with context-dependent roles emerging across distinct disease models and tissue microenvironments. Posttranslational modifications (PTMs) exert profound impacts on the stability, subcellular localization, and function of YAP/TAZ. The canonical Hippo pathway-mediated phosphorylation and ubiquitination have been well characterized as mechanisms that downregulate YAP/TAZ stability and transcriptional activity. Recent studies have identified novel phosphorylation sites, atypical ubiquitination patterns, along with ubiquitin-like modifications, glycosylation, methylation, acetylation, and lactylation on YAP/TAZ. These PTMs exhibit dynamic regulation in response to microenvironmental stimuli, providing molecular insights into the context-dependent functional versatility of YAP/TAZ. This review systematically synthesizes current understanding of YAP/TAZ PTM networks and discusses their therapeutic implications.

Background: The skin is subjected to constant mechanical stress in both healthy and wounded states. Macrophages play crucial roles in skin homeostasis and in all stages of the wound healing process. However, the effects of static mechanical stretch (MS) on macrophages and the subsequent consequences on skin cells remain largely unclear.

Methods: We applied static MS at amplitudes of 7%, 15%, and 21% to macrophages derived from THP-1 using a customized cell-stretching device, thoroughly investigating its impacts on viability, polarization, secretome, and underlying signaling pathways. Recognizing the substantial influence of the macrophage secretome on neighboring cells, we collected conditioned medium from macrophages exposed to MS (MS-CM) and evaluated its effects on keratinocytes, fibroblasts, and endotheliocytes.

Results: Macrophages exhibited a non-monotonic biological response to MS across the range of 7-21%, resulting in similar non-monotonic effects of MS-CM on the behaviors skin cell behaviors. The most significant effects were observed when macrophages were subjected to 15% MS. The 15% MS promoted macrophage viability and polarization toward the M2 phenotype, leading to increased release of anti-inflammatory cytokines and growth factors, as well as activation of the mechanotransduction pathways Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ). Consistent with these findings, 15% MS-CM enhanced the migration of keratinocytes, endotheliocytes, and fibroblasts, and promoted in vitro tube formation and fibroblast activation. In contrast, both 7% and 21% MS showed a similar tendency but with less pronounced or insignificant effects. Additionally, in a full-thickness wound model, the application of concentrated 15% MS-CM demonstrated additional beneficial effects on wound healing by enhancing angiogenesis and dermal reconstitution.

Conclusions: Our observation of the non-monotonic macrophage response to MS provides a foundation for elucidating how macrophages may translate mechanical cues into paracrine signals that influence skin function and wound healing dynamics.

Background: Mammalian arachidonic acid lipoxygenases (ALOXs) have previously been implicated in the pathogenesis of inflammatory disease, and pro- as well as anti-inflammatory activities have been reported. The human genome involves six functional ALOX genes and each of them encodes for a functionally distinct enzyme. ALOX15 is one of these isoforms and the majority of mammalian ALOX15 orthologs including mouse Alox15 convert arachidonic acid to its 12-hydroperoxy derivative. In contrast, human ALOX15 forms 15-hydroperoxy arachidonic acid instead. This difference in the catalytic properties of the two mammalian ALOX15 orthologs may be of biological relevance since arachidonic acid 15-lipoxygenating ALOX-isoforms exhibit an improved biosynthetic capacity for pro-resolving mediators. We recently generated Alox15 knock-in mice, which homozygously express a humanized Alox15 mutant (Leu353Phe) instead of the wildtype enzyme. These animals should be protected from the development of inflammatory symptoms in whole animal inflammation models if the biosynthesis of pro-resolving mediators plays a major role.

Methods: To explore whether functional humanization of mouse Alox15 might impact the pathogenesis of inflammatory diseases we tested Alox-KI mice in comparison with wildtype control animals in two whole animal inflammation models (dextran sodium sulfate induced colitis, Freund's complete adjuvant induced paw edema). In these experiments we quantified the severity of inflammatory symptoms during the acute phase of inflammation and during the resolution period.

Results: We found that Alox15 knock-in mice are strongly protected from the development of inflammatory symptoms in the dextran sodium sulfate colitis model when the loss of body weight was used as major readout parameter. Quantification of the colon tissue oxylipidomes revealed that the colon concentrations of resolvin D5 were elevated in Alox15-KI mice and thus, this mediator might contribute to the protective effect induced by our genetic manipulation. However, other specialized pro-resolving mediators, such as maresin-2, neuroprotectin-1, and lipoxins, may not play a major role for the protective response. In the Freund's complete adjuvant induced paw edema inflammation model no protective effect was observed.

Conclusions: Taken together, our data suggest that humanization of the reaction specificity of mouse Alox15 (Leu353Phe mutation) exhibits differential effects in two mouse inflammation models.