Metabolic disorders could cause dysregulated glucose and lipid at the systemic level, but how inter-tissue/organ communications contribute to glucolipotoxicity is difficult to dissect in animal models. To solve this problem, myocardium and nerve tissues were modelled by 3D engineered heart tissues (EHTs) and neural organoids (NOs), which were co-cultured in a generalised medium with normal or elevated glucose/fatty acid contents. Morphology, gene expression, cell death and functional assessments detected no apparent alterations of EHTs and NOs in co-culture under normal conditions. By contrast, NOs significantly ameliorated glucolipotoxicity in EHTs. Transcriptomic and protein secretion assays identified the extracellular matrix protein versican as a key molecule that was transferred from NOs into EHTs in the high-glucose/fatty acid condition. Recombinant versican protein treatment was sufficient to reduce glucolipotoxicity in EHTs. Adeno-associated virus-delivered versican overexpression was sufficient to ameliorate cardiac dysfunction in a murine model of diabetic cardiomyopathy. These data provide the proof-of-concept evidence that inter-tissue/organ communications exist in the co-culture of engineered tissues and organoids, which could be systemically studied to explore potential pathological mechanisms and therapeutic strategies for multi-organ diseases in vitro.

Ginsenoside Rg1 has shown promise in ameliorating cerebral ischemia–reperfusion injury (CIRI). However, its precise molecular mechanisms remain unclear. In this study, an in vitro CIRI model was established using SH-SY5Y and SK-N-AS neuronal cell lines subjected to oxygen–glucose deprivation followed by reoxygenation (OGD/R). For the in vivo model, C57BL/6J mice underwent middle cerebral artery occlusion and subsequent reperfusion (MCAO/R). The protective effects of Rg1 against OGD/R injury were analysed using the CCK-8 assay and the PI exclusion method. The in vivo neuroprotective effects of Rg1 against CIRI were evaluated using various assessments, including brain blood flow, neurological deficits, behavioural tests, TTC, H&E, Nissl and TUNEL staining. Mitophagy was assessed by detecting mitophagy-initiating proteins via Western blotting, transmission electron microscopy, immunohistochemistry and immunofluorescence staining. Additionally, mitochondrial function was assessed by ATP measurement, the JC-1 assay and MitoSOX-based flow cytometry. Our results show that Rg1 significantly mitigated cell death caused by OGD/R and substantially enhanced cell viability in vitro. Moreover, Rg1 alleviated OGD/R-induced mitochondrial dysfunction, as indicated by preserved mitochondrial membrane potential and decreased mitochondrial ROS levels. Mitophagy was induced after OGD treatment, which was subsequently inhibited by Rg1 during reperfusion. Mechanistically, Rg1 disrupted the fusion of mitophagosomes with lysosomes rather than inhibiting mitophagy initiation, leading to an accumulation of mitochondrial proteins and mitophagy-initiating proteins. Notably, prolonged inhibition of mitophagy by Rg1 did not induce cytotoxicity or exacerbate mitochondrial dysfunction. Furthermore, administration of Rg1 in MCAO/R mice significantly improved brain blood reperfusion, reduced infarct volume, improved neurological deficits, preserved brain tissue integrity and decreased neuronal apoptosis. Consistent with the in vitro observations, Rg1 upregulated mitophagy-related protein expression in MCAO/R mouse brain tissues, indicating potential inhibition of mitophagy. In conclusion, our study reveals that Rg1 significantly alleviates CIRI at least partially by suppressing mitophagy, specifically by impeding the fusion of mitophagosomes with lysosomes.

RING finger protein 219 (RNF219) is a co-factor for the CCR4-NOT deadenylase complex in mammals. Here, we found that mutations within the C3HC4 scaffold of the RING finger domain in RNF219 are capable of forming condensates via liquid–liquid phase separation (LLPS), though the wild-type RING finger domain intrinsically suppresses LLPS. We further demonstrated that the adjacent coiled-coil 1 (CC1) domain promotes the potential of RNF219 to form condensates. Moreover, the mutant RNF219 condensates are able to encapsulate the CCR4-NOT complex, inhibiting the RNA deadenylation activity of CCR4-NOT. Additionally, we observed that RNF219 mutations could promote cell proliferation. These findings suggest a pathogenic mechanism whereby RNF219 mutations could induce CCR4-NOT condensate formation, inhibit deadenylation-dependent mRNA decay and drive cell proliferation.

Neurodevelopmental impairment due to hypoxic–ischemic brain damage (HIBD) lacks effective biomarkers and therapeutic targets. Based on some cues from published papers, extracellular serine/threonine protein kinase FAM20C was speculated to play a crucial role in the neurodevelopmental impairment of HIBD. In this study, FAM20C was found suppressed in the ischemic hippocampal tissue of HIBD. The inhibition of FAM20C caused by HIBD affected cell differentiation and subsequently caused cognitive impairment. KAP1 was identified as a kinase substrate of FAM20C in the central nervous system. The regulation of the YTHDC1-NCL-KAP1-LINE1 RNA complex by FAM20C was mediated through KAP1 phosphorylation and LINE1 RNA m6A. These alterations consequently modulated the establishment of the H3K9me3 modification on LINE1 DNA, thereby resulting in neuronal differentiation. Furthermore, E2F4, identified as a transcription factor, regulated FAM20C in HIBD. This research has clarified the novel association between FAM20C and HIBD, laying the foundation for innovative diagnostic and therapeutic strategies to counteract neurodevelopmental disruptions arising from neonatal hypoxic–ischemic encephalopathy (HIE).

Hepatocellular carcinoma (HCC) remains a lethal malignancy with limited therapeutic options. Ferritinophagy, an autophagy-dependent process regulating iron metabolism, has emerged as a key contributor to ferroptosis and tumour progression. This study hypothesised that the ferritinophagy-related gene FTH1 drives HCC pathogenesis by modulating tryptophan metabolism and reactive oxygen species (ROS)-dependent ferroptosis. To test this, we first analysed TCGA data to identify prognostic ferritinophagy genes, revealing FTH1 as a critical risk factor. Functional experiments using FTH1-knockdown/−overexpressing HCC cell lines and xenograft models demonstrated that FTH1 enhances proliferation, migration, and tumour growth by upregulating CYP1A1/CYP1A2 in the tryptophan pathway, thereby increasing the synthesis of 6-hydroxymelatonin (6-HMT). Mechanistically, 6-HMT suppressed ROS and ferroptosis by inhibiting cytochrome P450 oxidoreductase (POR). Concurrently, intracellular tryptophan levels were found to inhibit NCOA4-mediated selective autophagy of FTH1, stabilising FTH1 levels and promoting tumour survival. Collectively, our findings establish FTH1 as a central regulator of ferritinophagy in HCC and reveal its dual role in linking tryptophan metabolism to redox homeostasis. This result provides a hint of how FTH1 influences HCC pathogenesis and positions the tryptophan metabolism pathway as a promising therapeutic target.

The inflammatory storm is a hallmark of acute respiratory distress syndrome (ARDS), yet effective therapies remain unavailable. FK506-binding protein 51 (FKBP5) has emerged as a regulator of inflammatory responses. In this study, FKBP5 expression was markedly increased in patients with sepsis and correlated with both cytokine levels and disease severity. Using sepsis-induced ARDS models in Fkbp5^−/− and bone marrow chimeric mice, this study demonstrated that non-haematopoietic FKBP5 mitigates inflammatory injury. Single-cell transcriptomic analysis identified fibroblasts and epithelial cells as the primary sources of non-haematopoietic FKBP5 in the lung injury. Conditional deletion of FKBP5 in fibroblasts (Col1a2-iCre Fkbp5^flox/flox) confirmed the essential role of fibroblast FKBP5 in the inflammatory response during ARDS. Mechanistically, FKBP5-mediated necroptosis of alveolar fibroblasts triggered NF-κB activation, proinflammatory cytokine release, neutrophil recruitment, and the establishment of an inflammatory microenvironment in alveolar epithelial tissue. These findings suggest a potential therapeutic strategy targeting fibroblast FKBP5 and provide a foundation for future clinical investigation in ARDS management.

Melasma is a recurrent and treatment-resistant hyperpigmentation disorder characterized by a complex and multifactorial pathogenesis. However, the lack of a stable and reliable animal model has hindered systematic investigations into its onset and progression. In this study, we established a melasma-like model in C57BL/6J mice by combining broadband UVB irradiation, intramuscular progesterone administration, and induced emotional stress. The affected skin areas exhibited irregular, brown hyperpigmented patches. Histopathological analysis revealed an accumulation of melanin granules in the epidermis and superficial dermis, elevated levels of tyrosinase (TYR) in both skin and plasma, systemic oxidative stress imbalance, and reduced autophagic activity in the lesional skin. Furthermore, this model displayed distinct differences from a UV-induced post-inflammatory hyperpigmentation (PIH) model. Notably, the melasma-like mice responded to tranexamic acid treatment in a manner that closely resembled clinical outcomes observed in human patients. Collectively, these findings establish a stable, reproducible, and clinically relevant mouse model of melasma, providing a valuable platform for future research into its pathogenesis and treatment.

SNARE proteins are required for membrane fusion events throughout the endomembrane system, and are therefore associated with vesicular transport. Here, we found that the SNARE family member, YKT6, is indispensable for male fertility in mice. Conditional Ykt6 knockout in pre-meiotic and meiotic germ cells leads to complete sterility and meiotic arrest in male mice, which exhibit loss of spermatocytes in seminiferous tubules, but without obvious disruption of chromosomal behaviours during meiosis. We observed that the abundance of syncytia increases along with abnormal morphology of the Golgi apparatus, while lysosomes decrease in Ykt6-cKO testes. Quantitative proteomics and immunofluorescent staining both showed dysregulation of vesicular transport in YKT6-deficient spermatocytes. Additionally, the recombinant mouse proteins, HA::YKT6 and MYC::STX1A, could interact in vitro, further supporting a likely role in mediating transport vesicle fusion with the plasma membrane. Finally, the absence of TEX14 signal within syncytia and enlarged TEX14 rings between spermatocytes together suggest a failure to stabilise intercellular bridges in Ykt6-cKO testes. These results demonstrate that YKT6 is required for male fertility by promoting meiosis progression through vesicular transport regulation during spermatogenesis in mice, expanding our understanding of YKT6 functions, and suggesting a possible strategy for future interventions for male infertility in humans.

Aminoglycoside antibiotics are essential in managing many life-threatening diseases. However, their derivatives, such as neomycin, are associated with severe side effects such as persistent sensorineural hearing loss. Therefore, it is essential to elucidate the molecular and biochemical mechanisms of aminoglycoside-induced ototoxicity and identify targets for alleviating ototoxic injury. Here, we provide a detailed cochlear cell atlas of neomycin-induced acute and chronic ototoxicity-related changes through single-nucleus RNA sequencing profiling. Utilising this cochlear cell atlas, we used the Augur and scDist algorithms to evaluate cell-type-specific susceptibility to neomycin injury. We observed aberrant expression of X-linked inhibitor of apoptosis (Xiap)–associated factor 1 (Xaf1) in neomycin-exposed cochleae using the cochlear cell atlas, and we identified a novel role for Xaf1 in facilitating PANoptosis through overexpression and knockdown assays in vitro. Finally, we assessed the protective role of Xaf1 against neomycin-induced ototoxicity by Xaf1 knockdown in cochlear hair cells using adeno-associated virus-based gene delivery. Mechanistically, Xaf1 orchestrates PANoptosis activation through direct interaction with and transcriptional regulation of ZBP1, establishing its hierarchical position upstream in the signalling cascade. This study presents detailed cochlear cellular maps of neomycin-induced ototoxicity and serves as a valuable resource for identifying transcriptome-wide disease-driving perturbations at the single-cell level. More importantly, we identified Xaf1 as a critical target for modulating the PANoptosis pathway, offering a promising treatment strategy for aminoglycoside-induced ototoxicity.

Piezo2, a mechanically activated ion channel, serves as the key molecular transducer for touch, proprioception and visceral sensation. These mechanosensation processes, where mechanical forces are converted into electrochemical signals, are essential for sensory perception, interoception and systemic homeostasis. Critically, Piezo2 channels are fundamental to diverse physiological functions, such as skeletal growth, respiratory development and inter-organ homeostasis. Despite its established role in sensory neurons and specialised mechanotransducers, the molecular intricacy of Piezo2-mediated signalling and its pathophysiological relevance remain incompletely understood. This review highlights key evidence from recent studies employing advanced technologies supporting the potential of Piezo2 channels as vital mechanosensor that regulate mechanotransduction cascades in physiological systems, demonstrating their potential as drug targets for the development of therapeutic agents.