Cells

Glioblastoma (GBM) is the most aggressive primary brain tumor, marked by molecular heterogeneity and poor clinical prognosis. Lysyl oxidase-like 3 (LOXL3) is frequently upregulated in GBM, but its mechanistic contribution remains insufficiently defined. Here, we investigated the functional role of LOXL3 in GBM using CRISPR-Cas9-mediated LOXL3 knockdown in two genetically distinct GBM cell lines: U87MG (wild-type TP53) and U251 (mutant TP53). Reduced LOXL3 expression markedly reduced α-tubulin acetylation, particularly in U87MG cells, and downregulated genes involved in cell cycle progression and proliferation. Both cell lines exhibited mitotic defects, including delayed cell cycle progression and spindle abnormalities; however, cell fate diverged according to TP53 status. U87MG cells, sustained spindle checkpoint activation triggered a p53-dependent spindle checkpoint response culminating in apoptosis, while U251 cells underwent mitotic slippage and senescence. Transcriptomic analyses confirmed differential regulation of apoptosis versus senescence pathways in accordance with TP53 functionality. Additionally, reduced LOXL3 expression markedly impaired adhesion and migration in U87MG cells, whereas U251 cells were minimally affected, consistent with more pronounced microtubule destabilization. Collectively, these findings identify that LOXL3 is a key regulator of microtubule homeostasis, mitotic fidelity, adhesion, and invasive behavior in GBM. Targeting LOXL3 may therefore provide a therapeutic opportunity for genotype-informed intervention in GBM.

Abdominal aortic aneurysm (AAA) is a serious disease with no effective pharmacological therapy. Although inflammation is recognized as a key regulator of AAA, targeting inflammatory pathways once the disease is established does not improve outcomes. Understanding the earliest molecular indicators could clarify precise biological targets and prognostic markers for AAA. Using ApoE-deficient mice, we performed RNA-Seq on suprarenal abdominal aortas (SRAs) from Ang II- and saline-treated mice 24 h after infusion. We further developed a unique model of hyperlipidemic mice in which the expression of the inhibitor of nuclear factor kappa B kinase subunit beta (IKKβ) can be conditionally suppressed in vascular smooth muscle cells (VSMCs). RNA-Seq data revealed early IKKβ-dependent cellular anabolic processes in SRAs, including activation of the mammalian target of rapamycin complex 1 (mTORC1) pathway. Furthermore, deletion of the Ikbkb gene in VSMCs significantly reduced the rate of aneurysm rupture in mice exposed to Ang II. In situ analysis further confirmed that the absence of IKKβ in VSMCs is associated with a reduced inflammatory response and the preservation of their contractile phenotypes. Our results reinforce the crucial role of VSMCs in rapid adaptation, leading to deleterious inflammation-dependent remodeling of the vascular wall, and define a previously unrecognized anabolic role of IKKβ in AAA pathogenesis.

The 25 kDa glycoprotein lipocalin-2 (LCN2) is widely expressed and has diverse functions, ranging from physiological to pathophysiological processes. In the liver, LCN2 is primarily associated with inflammatory processes and is considered a potential biomarker in metabolic disorders. However, a significant challenge is the absence of a suitable human in vitro model for studying LCN2 and its associated signaling pathways. Therefore, we have successfully generated patient-derived liver organoids of both male and female origin, providing a novel in vitro model for LCN2 research. Our data show that the self-renewing organoids mimic essential architectural features of hepatocytes, as demonstrated by electron microscopy and F-actin staining. Consistent with the expression profile observed in liver tissue, the isolated 3D organoids exhibit minimal endogenous LCN2 levels. Next, the LCN2 expression was studied at the protein and mRNA levels under inflammatory conditions by treating the organoids with various cytokines and lipopolysaccharides (LPS). Our results show that LCN2 expression is significantly upregulated by IL-1β and TNF-α in an NF-κB-dependent manner, but remains unchanged with IL-6 or LPS. In conclusion, we have established human patient-derived liver organoids as a valuable model for investigating LCN2 signaling mechanisms. This study lays the foundation for future research on the role of LCN2 in liver pathologies, aiding in disease progression understanding and facilitating patient-specific treatment predictions.