Periapical periodontitis is one of the most common inflammatory bone destructive diseases. Epidemiological evidence suggests that hypoxia exposure, such as that resulting from high-altitude exposure or sleep apnea syndrome, may be a significant risk factor that exacerbates the disease process. However, its specific role and the underlying molecular mechanisms remain unclear. In this study, we established a mouse model of periapical periodontitis under conditions of chronic hypoxia to evaluate its impact on pathological bone loss using micro-computed tomography, histological staining, and serum cytokine analysis. Furthermore, we explored the potential molecular regulatory mechanisms using in vitro osteoclast differentiation models, adeno-associated virus-mediated in vivo gene knockdown, and cleavage under targets and tagmentation (CUT&Tag) sequencing. Our study revealed that hypoxia exposure significantly aggravated alveolar bone resorption, osteoclast activation, and systemic inflammation in the mouse model of periapical periodontitis compared to normoxia. At the molecular level, hypoxia-inducible factor-1α (HIF-1α) showed a rapid but transient increase under hypoxia, whereas HIF-2α displayed a progressive and sustained elevation throughout osteoclast differentiation. These dynamics indicate that HIF-2α plays a more prominent role than HIF-1α in mediating the hypoxia-accelerated osteoclastogenic response. In vivo, local knockdown of HIF-2α in the periapical region markedly attenuated bone destruction exacerbated by hypoxia exposure. Further mechanistic investigation, combining CUT&Tag sequencing and functional validation experiments, revealed that HIF-2α mediates its pro-osteoclastogenic function by directly binding to the promoter region of the calmodulin-dependent protein kinase IV (Camk4) gene and activating its transcription. This study unveils that hypoxia exposure, acting as a critical environmental risk factor, functions as a ‘synergistic amplifier’ to enhance pathological osteoclastic responses in periapical periodontitis through the HIF-2α–CAMK4 regulatory axis. The findings deepen our understanding of periapical periodontitis and suggest that targeting HIF-2α or downstream pathways may be an adjunctive therapeutic strategy for hypoxia-associated inflammatory bone loss.

Liver grafts from donation-after-cardiac-death (DCD) are vulnerable to ischemia–reperfusion injury, which compromises graft function after transplantation. Agrimoniin has been shown to possess antioxidant and anti-inflammatory properties, making it a potential therapeutic agent for organ preservation. This study investigated whether supplementing agrimoniin to the University of Wisconsin (UW) cold storage solution protected liver grafts from DCD rats or cold preserved human liver cell lines (QSG-7701 and HepG2). Agrimoniin supplementation significantly reduced oxidative damage, alleviated ferroptosis, and mitigated liver injury by activating the Nrf-2 pathway, both in vivo and in vitro. These findings suggest that ferroptosis is a mediator in DCD liver injury, and agrimoniin, through its activation of the Nrf-2 pathway, may be an effective therapeutic agent for enhancing liver graft preservation and improving outcomes in DCD liver transplantation.

Retinal neovascularisation (RNV) is manifested in various retinal pathological conditions, often leading to irreversible blindness. The oxygen-induced retinopathy (OIR) mouse model proves to be a useful tool for understanding RNV pathogenesis. In this model, retinal vascular phenotype undergoes two distinct stages: neovascular formation, followed by spontaneous regression. While microglial functions in the neovascular formation stage have been extensively studied, their behaviors and roles during regression remain unclear. In this study, we characterise the spatiotemporal dynamics and molecular heterogeneity of retinal microglia across both stages. During RNV formation, microglia exhibit an outer-to-inner and central-to-midperipheral migration pattern, whereas a reversed migration trend is observed during regression. We confirm a highly glycolytic microglia (HGM) subpopulation during RNV formation and demonstrate its pro-angiogenic role by targeting a highly expressed pyruvate kinase M2 (Pkm2), a crucial enzyme for glycolysis. Importantly, we find that microglia exhibit enhanced phagocytic activity during regression, constituting a distinct phagocytosis-associated microglia (PAM) subtype, expressing mannose receptor C-type 1 (Mrc1/CD206). Altogether, our findings reveal stage-specific microglial functional dynamics, providing novel insights into RNV pathogenesis and intervention.

Failure of timely bone regeneration compromises structural integrity and delays functional recovery; therefore immune regulation of the early repair microenvironment is crucial for successful healing. M1 (pro-inflammatory) phenotype macrophages play pivotal roles in vascularisation during the early phase of bone regeneration and are typically activated by interferon-gamma (IFN-γ) or lipopolysaccharide (LPS) as well as by metabolite-derived signals. Lactate, a metabolite known to regulate a series of pathophysiological processes, has not yet been fully investigated for its specific immunomodulatory role in the microenvironment of bone injury healing. Our in vitro experiments demonstrated that lactate induced macrophage polarisation to the M1 phenotype and accelerated angiogenesis, with the HIF1α-NOD1-calcium influx axis identified as a key mediator. In vivo validation further confirmed the positive effects of lactate intervention in promoting vascularised bone regeneration at the early stage of injury. Thus, this study uncovers how lactate modulates immune response in association with M1 macrophages and indicates its potential as a therapeutic strategy for promoting vascularised bone healing.

The dysfunctional reconstitution of the intestinal barrier is pivotal in driving the initiation of inflammatory pathogenesis in Crohn's disease (CD), although the exact pathophysiology underlying this phenomenon has yet to be definitively characterised. This study aimed to investigate the role of the histone methyltransferase mixed lineage leukaemia 1 (MLL1) in the development of CD-like colitis and to elucidate the mechanism by which MLL1 promotes epithelial cell differentiation. Colonic tissue specimens from CD patients and TNBS-induced murine models were analysed to assess MLL1 expression dynamics. The functional impact of MLL1 on murine colitis modelling CD was systematically investigated through clinical symptom scoring, histopathological profiling and quantitative evaluation of intestinal barrier integrity. The role of MLL1 in promoting epithelial cell differentiation and repairing the intestinal barrier was investigated through immunofluorescence and western blotting. Additionally, potential mechanisms underlying the reparative effects of MLL1 on intestinal barrier function were explored. MLL1 expression was upregulated in colonic tissues from CD patients and TNBS-induced murine colitis models. In contrast, MLL1 suppression in the TNBS cohort attenuated mucosal inflammation and downregulated pro-inflammatory cytokine production (IL-1β, IL-6, TNF-α) within the colonic mucosa. Additionally, reduced MLL1 expression increased the differentiation capacity of intestinal epithelial cells, including goblet cells, absorptive cells and tuft cells, and promoted barrier function restoration in injured colons and lipopolysaccharide-stimulated colonic organoids. MLL1 downregulation activated the Gata4/Bmp4 signalling pathway, which may contribute to the reparative effects of MLL1 on intestinal barrier integrity. Downregulating MLL1 expression promotes intestinal epithelial cell differentiation by activating the Gata4/Bmp4 pathway. These findings elucidate a pathophysiological mechanism wherein MLL1 suppression potentiates intestinal barrier restoration, thereby attenuating colitis severity in murine models. The observed therapeutic efficacy positions MLL1 inhibition presents a novel strategy for CD management.

Although the role of retinoic acid (RA) signalling in odontogenesis is well established, its involvement in the repair of injured tooth germs remains unclear. To investigate this, we generated a Tg(scpp5:Dendra2-NTR) zebrafish line for labelling tooth germ cells and established a tooth germ injury model using the nitroreductase (NTR)/metronidazole (MTZ) system. We then modulated RA signalling by exogenous activation with RA, retinol, retinal, talarozole (TZ) or Tg(hsp70l:aldh1a2-p2a-mCherry; cryaa:venus), and by suppression with 4-diethylaminobenzaldehyde (DEAB) or Tg(hsp70l:dnRARAA-p2a-DsRed; cryaa:venus), to examine its function in tooth germ repair. Following targeted ablation of tooth germ cells, RA signalling was activated, with aldh1a2 showing the most pronounced upregulation. Exogenous RA promoted injury-induced tooth germ repair, whereas its precursors (retinol and retinal) had no significant effect on aldh1a2 expression or repair. Pharmacological inhibition of RA degradation with TZ enhanced repair, while dominant-negative inhibition of RA signalling impaired it. Furthermore, modulation of aldh1a2 revealed its essential role: inhibition with DEAB attenuated repair, whereas genetic activation facilitated tissue restoration. In summary, this study clarifies the regulatory role of RA signalling in tooth germ injury repair, offering a theoretical foundation and potential therapeutic targets for the treatment of injured tooth germs.

Although Myo-Inositol/D-Chiro-Inositol (Ins) and berberine (BBR) have each shown beneficial effects in polycystic ovary syndrome (PCOS), their combined therapeutic potential has not been systematically evaluated. Here, we demonstrate that Ins/BBR exerts superior efficacy compared with single treatments by targeting multiple pathogenic pathways in PCOS. In a DHEA+HFD-induced mouse model, Ins/BBR restored systemic sex steroid balance, normalized LH/FSH ratio, and improved estrous cyclicity. It also reduced ovarian cysts and enhanced fertility, accompanied by partial normalization of steroidogenic enzyme expression. At the cellular level, Ins/BBR alleviated mitochondrial defects and broadly reprogrammed metabolic landscape in granulosa cells, in specific, restoring nucleotide pools and amino acid turnover and preventing abnormal long-chain fatty acid accumulation. Together, these findings provide preclinical evidence that Ins/BBR acts through coordinated endocrine, ovarian and metabolic mechanisms, supporting its promise as a safe and effective therapeutic strategy for PCOS.

Huntington's disease (HD) is an inherited neurodegenerative disease characterised by progressive degeneration of GABAergic medium spiny neurons (MSNs) in the striatum. Neural precursor cells (NPCs) derived from human induced pluripotent stem cells (iPSCs) have been considered as a promising and scalable source for neuronal replacement and circuit restoration. In this study, we investigated the therapeutic effects of a clinical-grade, human leukocyte antigen (HLA)-homozygous iPSC line (YZWJ-s513) differentiated into NPCs (s513-NPCs) in a quinolinic acid (QA)-lesioned rat model of HD. Following intrastriatal transplantation, s513-NPCs not only survived for 12 weeks but also differentiated into neurons, astrocytes, and oligodendrocytes, while generating new DARPP32⁺ GABAergic MSNs. Specifically, graft-derived neurons projected to the host globus pallidus, indicating structural integration into the striato-pallidal pathways. Additionally, NPC-transplanted rats exhibited significant motor recovery across multiple tasks for up to 12 weeks, accompanied by reduced striatal atrophy and ventricular enlargement. Histological findings also revealed attenuated astrogliosis and microgliosis, along with a shift toward an anti-inflammatory milieu. Collectively, these results demonstrate that transplantation of clinical-grade, HLA-homozygous iPSC-derived NPCs can provide both neuronal replacement and modulation of the diseased microenvironment, supporting their potential as a regenerative therapy for HD. Key quality attributes and release criteria supporting the clinical-grade characterisation of the cell product used in vivo are summarised in Table S1.

Airway remodelling is a major contributor to persistent airflow limitation and irreversible lung function impairment in asthma, with epithelial-mesenchymal transition (EMT) serving as a key driver. However, the molecular mechanisms controlling EMT in asthma epithelium remain incompletely elucidated. This study reported that integrin α5 (ITGA5) was markedly upregulated in asthma patients, house dust mite (HDM)-sensitised asthma mice, and transforming growth factor beta 1 (TGF-β1)-induced in vitro EMT models. Elevated ITGA5 expression correlated positively with reduced lung function, asthma severity and higher levels of EMT regulators (Fibronectin, N-cadherin, Vimentin) and was functionally linked to anoikis resistance. In TGF-β1-induced bronchial epithelial cells exhibiting anoikis resistance, quantitative proteomics revealed that ITGA5 promoted mesenchymal transition via the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway and negatively regulated anoikis. ITGA5 directly bound to PI3K in vitro, and ITGA5 knockdown reversed TGF-β1-induced EMT, inhibited the activation of the PI3K/Akt pro-survival pathway, and restored anoikis sensitivity. According to molecular docking, molecular dynamics simulation and in vivo and in vitro pharmacological assays, resveratrol (Res) and M200 were found to be potential ITGA5 inhibitors that successfully reduced EMT and anoikis resistance, thereby attenuating airway remodelling in asthma mice and offering promising drug candidates for ITGA5-targeted therapy.

Osteocytes, the central regulators of bone remodelling, are essential for maintaining bone homeostasis. Embedded in a nutrient-limited matrix and burdened by cumulative stress over their exceptionally long lifespan, how osteocytes sustain long-term viability remains elusive. Tunnelling nanotubes (TNTs) are newly described intercellular bridges that enable long-range transfer of organelles and have been implicated in stress adaptation. Here, we provide the first definitive identification of TNTs between cultured osteocytes, which exhibit canonical TNT morphology together with osteocyte-specific features. Functionally, osteocytic TNTs mediate intercellular transfer of membrane-bound cargo, predominantly lysosomes. Under nutrient deprivation, TNT formation and lysosome transfer are both increased, replenishing the lysosomal pool in stressed osteocytes. Transferred lysosomes then fuse with accumulated autophagosomes, thereby restoring impaired autophagic flux and suppressing apoptosis. This cytoprotective effect requires TNT integrity and intact autophagic flux. Although mitochondrial transfer is detectable, it does not confer comparable protection. The findings identify a transcellular autophagy pathway mediated by TNT-dependent lysosome sharing, revealing a previously unrecognized cooperative survival strategy among osteocytes. This work establishes a novel conceptual framework in osteocyte biology and suggests potential therapeutic avenues for bone diseases associated with osteocyte apoptosis and impaired bone remodelling.

Chronic kidney disease (CKD) has emerged as a critical public health challenge worldwide, and organ donor shortages underscore the urgent need for alternative therapeutic strategies. Advances in stem cell technologies have enabled the generation of kidney organoids, providing innovative platforms to model renal development, investigate disease mechanisms, support drug discovery, and explore applications in regenerative medicine. Yet, limitations such as immature tissue architecture, insufficient vascularisation, and unaddressed safety concerns still hinder their translation into regenerative medicine. In this review, we summarise the fundamentals of kidney development, current differentiation approaches, and the signalling and epigenetic mechanisms underlying organoid lineage specification. We further highlight the roles of bioengineering innovations and single-cell transcriptomics in establishing evaluation frameworks and enhancing structural complexity. We finally emphasise that existing optimisation frameworks, primarily focused on improving differentiation efficiency and enforcing relatively restricted lineage specification, may prove inadequate for bridging the gap to clinical translation. Instead, the most promising paradigm shift involves the convergence of bioengineering modulation and high-resolution functional assessment to facilitate the synchronised advancement of organoid complexity and physiological utility.

The immunosuppressive tumour immune microenvironment (TIME) is a fundamental barrier that renders “cold” tumours resistant to conventional cancer immunotherapies. Nanozymes, catalytic nanomaterials with enzyme-mimicking activities, have emerged as powerful and versatile agents for reprogramming the TIME and igniting robust antitumour immunity. This review systematically elucidates how nanozymes, through their multi-enzyme catalytic properties, orchestrate a multifaceted attack on the immunosuppressive TIME by regulating reactive oxygen species, alleviating hypoxia, depleting antioxidants, and inducing immunogenic cell death, ferroptosis, and cuproptosis. These catalytic actions collectively promote dendritic cell maturation, enhance cytotoxic T lymphocyte infiltration, and repolarise tumour-associated macrophages toward an M1 phenotype, thereby effectively converting immunologically “cold” tumours into “hot” ones. Furthermore, we deeply analyse the synergistic potential of nanozymes when integrated with established therapies—including immune checkpoint blockade, phototherapy, sonodynamic therapy, chemotherapy, and radiotherapy. Finally, by discussing advanced bioengineered platforms and addressing the ongoing challenges related to biosafety and clinical translation, we envision that nanozyme-based catalytic immunoengineering represents a paradigm-shifting approach for next-generation combinatorial cancer immunotherapy.