Fibrosis, which is characterized by pathological extracellular matrix (ECM) accumulation impairing organ function, is governed primarily by dysregulated transforming growth factor-β (TGF-β)/Smad signalling. TGF-β1 triggers canonical (Smad2/3-dependent) and noncanonical pathways upon receptor binding, driving profibrotic processes such as fibroblast activation, epithelial–mesenchymal transition (EMT), excessive ECM production (e.g., collagen), and the suppression of matrix degradation. This pathway is central to organ-specific fibrogenesis: In liver fibrosis, it activates hepatic stellate cells (HSCs); in renal fibrosis, it promotes tubular injury and ECM deposition; in pulmonary fibrosis, it induces EMT/fibroblast transition in radiation/bleomycin models; in cardiac fibrosis, it mediates fibroblast activation in diabetic cardiomyopathy/atrial fibrillation via NPRC/TGIF1/USP mechanisms; and in skin fibrosis (e.g., scleroderma), it stimulates collagen overproduction, which is suppressed by osthole or mesenchymal stem cells. The TGF-β/Smad axis thus represents a pivotal therapeutic target. Future research should clarify tissue-specific regulatory networks and develop combinatorial antifibrotic strategies.

The Keap1-Nrf2 signaling pathway is a major regulator of the cytoprotective response, participating in endogenous and exogenous stress caused by ROS (reactive oxygen species). Nrf2 is the core of this pathway. We summarized the literature on Keap1-Nrf2 signaling pathway and summarized the following three aspects: structure, function pathway, and cancer and clinical application status. This signaling pathway is similar to a double-edged sword: on the one hand, Nrf2 activity can protect cells from oxidative and electrophilic stress; on the other hand, increasing Nrf2 activity can enhance the survival and proliferation of cancer cells. Notably, oxidative stress is also considered a marker of cancer in humans. Keap1-Nrf2 signaling pathway, as a typical antioxidant stress pathway, is abnormal in a variety of human malignant tumor diseases (such as lung cancer, liver cancer, and thyroid cancer). In recent years, research on the Keap1-Nrf2 signaling pathway has become increasingly in-depth and detailed. Therefore, it is of great significance for cancer prevention and treatment to explore the molecular mechanism of the occurrence and development of this pathway.

Nrf2 (nuclear factor E2-related factor 2, encoded by Nfe2l2) acts as a master transcriptional regulator in mediating antioxidant, detoxification, and cytoprotective responses against oxidative, electrophilic, and metabolic stress, but also plays a crucial role in cancer metabolism and multiple oncogenic pathways, whereas the redox sensor Keap1 functions as a predominant inhibitor of Nrf2 and, hence, changes in its expression abundance directly affect the Nrf2 stability and transcriptional activity. However, nuanced functional isoforms of Keap1 α and β have rarely been identified to date. Herein, we have established four distinct cell models stably expressing Keap1^−/−, Keap1β(Keap1^Δ1–31), Keap1-Restored, and Keap1α-Restored aiming to gain a better understanding of similarities and differences of two Keap1 isoforms between their distinct regulatory profiles. Our experimental evidence revealed that although Keap1 and its isoforms are still localized in the cytoplasmic compartments, they elicited differential inhibitory effects on Nrf2 and its target HO-1. Furthermore, transcriptome sequencing unraveled that they possess similar but different functions. Such functions were further determined by multiple experiments in vivo (i.e., subcutaneous tumour formation in nude mice) and in vitro (e.g., cell cloning, infection, migration, wound healing, cell cycle, apoptosis, CAT enzymatic activity, and intracellular GSH levels). Of note, the results obtained from tumourigenesis experiments in xenograft model mice were verified based on the prominent changes in the PTEN signaling to the PI3K-AKT-mTOR pathways, in addition to substantially aberrant expression patterns of those typical genes involved in the EMT (epithelial–mesenchymal transition), cell cycle, and apoptosis.

Glioma, particularly glioblastoma (GBM), represent a major challenge in neuro-oncology due to their highly aggressive nature and poor therapeutic outcomes. The presence of the blood-brain barrier (BBB) severely restricts the efficient delivery of therapeutic agents to tumor sites, while the frequent emergence of drug resistance further compromises treatment efficacy. In recent years, nanoparticles have emerged as promising drug delivery platforms, demonstrating considerable potential in overcoming the BBB, enhancing targeting specificity, and reversing drug resistance, owing to their favorable biocompatibility and tunable physicochemical properties. This review provides a comprehensive overview of recent advances in the application of nanoparticles for glioma therapy, with a particular focus on strategies for BBB penetration and resistance reversal. Specifically, we summarize the design principles and functional modifications of nanoparticles, as well as their diverse therapeutic mechanisms, including drug delivery, photothermal and photodynamic therapy, ferroptosis induction, and modulation of the tumor microenvironment. In addition, the mechanisms underlying nanoparticle-mediated targeting and controlled drug release are discussed in detail. Importantly, current evidence suggests that nanoparticle-based platforms offer a versatile and effective approach for overcoming key biological barriers and therapeutic resistance in glioma, although their clinical translation remains constrained by challenges related to safety, scalability, and targeting heterogeneity. Future research should focus on the development of multifunctional and personalized nanomedicine strategies, integration with multimodal therapies, and rigorous evaluation of long-term safety and clinical efficacy, in order to facilitate the successful translation of these technologies into clinical practice.