The lack of accurate understanding of cellular physiology and pathophysiology during the WOI constitutes the major obstacle to correct diagnosis and treatment for patients with recurrent implantation failure (RIF). The role of cilia as one of the key organelles in endometrial epithelium has been poorly understood during embryo implantation. In this study, the morphological and molecular changes of endometrial cilia regulated by hormones were demonstrated in endometrial epithelial organoid models. Multi-omics studies revealed highly relevant cilia-related activities like cilia movement during endometrial receptivity establishment. Interestingly, both in vitro model and in vivo patient data have shown that the apical part of cilium formed a cilia-derived spherical structure after hormone stimulation. We also found intraflagellar transport (IFT) train multi-subunit complex B (IFT-B) was aggregated in the sphere during the implantation window. Meanwhile mitochondria localization signal increased at the cilia basement. Proteomics and the functional assay showed the deficiency of energy metabolism in RIF patients and cilia formation abnormalities. The abnormal energy supply resulted in the failure of vesicle transport by deficiency of IFT-B location, ultimately leading to the failure of receptivity establishment. Our study revealed the essential role of endometrial cilia in embryo implantation and indicated that mitochondrial metabolism was crucial for normal ciliogenesis and embryo implantation.

Retinal ischaemia/reperfusion injury (RI/RI) is the primary pathophysiological mechanism underlying retinal ischaemic diseases, potentially resulting in significant and irreversible visual impairment. Currently, there are no effective treatments available for RI/RI, and oxidative stress is a critical factor that contributes to the associated damage. DJ-1, an important endogenous antioxidant, has been proposed as a promising therapeutic agent for RI/RI owing to its potential for overexpression. In this study, tetrahedral frame nucleic acids (tFNAs) were utilised as an effective delivery vehicle for DJ-1 small activating RNA (saRNA), resulting in the synthesis of a novel nanocomposite (tFNAs-DJ-1-saRNA). In vitro experiments demonstrated that tFNAs effectively delivered DJ-1-saRNA to R28 cells, thus exerting a repair effect on oxidative stress injury. In vivo investigations revealed that the intravitreal injection of tFNAs-DJ-1-saRNA facilitated retinal DJ-1 gene expression and mitigated retinal atrophy induced by RI/RI. Mechanistically, tFNAs-DJ-1-saRNA activated the xCT/GPX4 pathway, thereby inhibiting ferroptosis, reducing ganglion cell damage and protecting the retinal tissue. In conclusion, this study demonstrated that the tFNAs-DJ-1-saRNA complex can ameliorate RI/RI by inhibiting ferroptosis, suggesting its potential as a novel agent for the treatment of retinal ischaemic diseases.

Chronic obstructive pulmonary disease (COPD) is characterised by chronic inflammation and senescence. Previous studies showed that club cells and club cell secretory proteins (CCSP) have anti-inflammatory roles, which reduced in COPD. Klotho (KL) decreased in human COPD lung tissue. KL-deficient mice showed aging phenotypes, such as obvious emphysema and premature senility at the early stage, which are characteristics of COPD. However, little is known about the relationship between KL, club cells, and COPD. We speculated lack of KL would aggravate club cell senescence, which contributes to COPD inflammation. We collected COPD lung tissue using single-cell RNA sequencing (scRNA-seq), revealing club cells heterogeneity and cellular senescence in COPD. In addition, KL and CCSP expressions were downregulated in cigarette smoke (CS)-induced COPD mice, associated with increasing age-related markers. After KL knockout, more ciliated cells appeared where club cells disappeared. Furthermore, KL deficiency aggravated club cell senescence and CSE-induced pulmonary inflammation. To investigate the specific regulation mechanism, hnRNPA2/B1 was recognised and identified it was the key molecule in KL-regulated club cell senescence, and neddylation of club cell was a crucial factor contributing to hnRNPA2/B1 downregulation. In vitro, SA-β-gal staining suggested the aging phenotype was aggravated in hnRNPA2/B1-silenced groups, and hnRNPA2/B1 over-expressed achieved a rescue result. Thus, KL could regulate club cell senescence and differentiation. When CS stimulates the small airway epithelium, KL deficiency aggravates lung inflammation, club cell senescence and dysfunctional of ciliated cell. Targeting neddylation might be a promising strategy to reverse lung aging and club cell senescence. These results provide a mechanism about COPD-linked lung inflammation.

To date, generating viable and functional hepatocytes in large scale remains challenge. By employing 3D suspension condition with the support of low concentration Matrigel, a novel culture system was developed to generate expandable hepatoblast organoids (HB-orgs) and mature polarised hepatocyte organoids (P-hep-orgs) from human embryonic stem cells (hESCs) in both dishes and bioreactors. scRNA-seq and functional assays were used to characterise HB-orgs and P-hep-orgs. hESC-derived HB-orgs could proliferate at least for 15 passages, leading to 10¹² in total cells in 4 weeks. P-hep-orgs differentiated from HB-orgs displayed characteristics of mature hepatocytes with polarisation. Moreover, single-cell RNA sequencing exhibited that over 40% of cells in P-hep-orgs were highly fidelity with human primary hepatocytes. Eventually, large-scale production of P-hep-orgs could be generated from massively expanded HB-orgs within 1 week with similar number in bioreactors, which were achieved by the enhancements in energy metabolism contribute to the expansion of HB-orgs and maturation of P-hep-orgs in bioreactors. By providing a cost-efficient and robust platform, our study represents a significant step toward manufacturing large-scale functioning hESC-derived hepatocytes for cell-based therapeutics, disease modelling, pharmacology and toxicology studies.

m.3243A>G is the most common pathogenic mtDNA mutation. High energy-demanding organs, such as heart, are usually involved in mitochondria diseases. However, whether and how m.3243A>G affects cardiomyocytes remain unknown. We have established patient-specific iPSCs carrying m.3243A>G and induced cardiac differentiation. Cardiomyocytes with high m.3243A>G burden exhibited hypertrophic phenotype. This point mutation is localised in MT-TL1 encoding tRNA^{Leu (UUR)}. m.3243A>G altered tRNA^{Leu (UUR)} conformation and decreased its stability. mtDNA is essential for mitochondrial function. Mitochondria dysfunction occurred and tended to become round. Its interaction with ER, mitochondria-associated ER membrane (MAM), was disrupted with decreased contact number and length. MAM is a central hub for calcium trafficking. Disrupted MAM disturbed calcium homeostasis, which may be the direct and leading cause of cardiomyocyte hypertrophy, as MAM enforcement reversed this pathological state. Considering the threshold effect of mitochondrial disease, mito-TALENs were introduced to eliminate mutant mitochondria and release mutation load. Mutation reduction partially reversed the cellular behaviour and made it approach to that of control one. These findings reveal the pathogenesis underlying m.3243A>G from perspective of organelle interaction, rather than organelle. Beyond mitochondria quality control, its proper interaction with other organelles, such as ER, matters for mitochondria disease. This study may provide inspiration for mitochondria disease intervention.

Proper segregation of homologous chromosomes during meiosis requires crossovers that are tightly regulated by the chromosome structure. PDHA2 is the testis-specific paralog of PDHA1, a core subunit of pyruvate dehydrogenase. However, its role during spermatogenesis is unclear. We show that PDHA2 knockout results in male infertility in mice, but meiotic DSBs in spermatocytes occur normally and are efficiently repaired. Detailed analysis reveals that mid/late recombination intermediates are moderately reduced, resulting in fewer crossovers and many chromosomes without a crossover. Furthermore, defective chromosome structure is observed, including aberrant histone modifications, defective chromosome ends, precocious release of REC8 from chromosomes and fragmented chromosome axes after pachytene. These defects contribute to the failure of pyruvate conversion to acetyl-CoA, resulting in decreased acetyl-CoA and precursors for metabolites and energy in the absence of PDHA2. These findings reveal the important functions of PDHA2 in ensuring proper crossover formation and in modulating chromosome structure during spermatogenesis.

Human midbrain organoids with functional dopaminergic (DA) neurons are invaluable for the therapeutic development of Parkinson's disease (PD). However, current methods face significant limitations, including challenges in generating pint-sized organoids enriched with DA neurons and the lack of robust functional assays for efficiently evaluating neural networks over extended periods. Here we present an innovative approach that combines developmental patterning with mechanical cutting to produce small midbrain organoids, with diameters less than 300 μm, suitable for long-term evaluation, along with a comprehensive functional assay system consisting of calcium transient assay, neurite extension assay, and multielectrode array (MEA) assay. Radial cutting of organoids into four to eight portions according to their sizes at the appropriate developmental stage significantly increases the yield of viable organoids while reducing necrotic cell regions. Using the functional assay system, we demonstrate that DA neurons within the organoids extend long projections, respond to dopamine stimulation, and form neural networks characterised by giant depolarising potential-like events. Our approach supports the generation of midbrain organoids and PD models that can be used for long-term functional testing.

Hepatocellular carcinoma (HCC) is one of the most challenging malignancies of the digestive system. Screening for novel biomarkers and therapeutic targets is a promising strategy to enhance HCC prognosis. Recently, liquid biopsy with circulating nucleic acids as the detection targets has attracted much attention in the field of early screening of tumours. However, the diagnostic value and biological functions of transfer RNA-derived small RNAs (tsRNAs) in serum, particularly in HCC, remains unknown. In this study, we characterised the expression profile of tsRNAs in hepatitis B virus (HBV)-related HCC, and confirmed the diagnostic potential of serum tRF-3a-Pro. On this basis, we established a diagnostic model that integrates tRF-3a-Pro with the classic HCC biomarker alpha-fetoprotein (AFP) through logistic regression analysis. Besides, both in vivo and in vitro experiments demonstrated that tRF-3a-Pro, a highly expressed tsRNA, promotes HCC cell proliferation. These findings suggested that tRF-3a-Pro could serve as a novel biomarker for HBV-related HCC.

Metabolic syndrome encompasses a cluster of predictive metabolic risk factors, including obesity, insulin resistance, dyslipidemia, hyperglycemia and hypertension. It is strongly associated with the development of type 2 diabetes and cardiovascular disease. Given the increasing morbidity and mortality associated with metabolic syndrome, along with the limited availability of drug treatments, it is high time to investigate the pathogenesis of this condition and explore potential pharmacotherapies. Macrophages, well-known innate immune cells, play an essential role in maintaining tissue immune homeostasis and multiple physiological processes, including glucose and lipid metabolism, oxidative stress and inflammation. Emerging evidence indicates that the effects of macrophages in metabolic syndrome are linked to macrophage-mediated metaflammation. Phytochemicals derived from natural plants have been shown to exert therapeutic effects on metabolic syndrome by modulating macrophage function. In this review, we sort out the role of macrophage-mediated metaflammation in the pathogenesis of metabolic syndrome and summarise potential phytochemicals that target macrophages for the treatment of this condition.

Ageing is often accompanied by cognitive decline and an increased risk of dementia. Exercise is a powerful tool for slowing brain ageing and enhancing cognitive function, as well as alleviating depression, improving sleep, and promoting overall well-being. The connection between exercise and healthy brain ageing is particularly intriguing, with exercise-induced pathways playing key roles. This review explores the link between exercise and brain health, focusing on how skeletal muscle influences the brain through muscle–brain crosstalk. We examine the interaction between the brain with well-known myokines, including brain-derived neurotrophic factor, macrophage colony-stimulating factor, vascular endothelial growth factor and cathepsin B. Neuroinflammation accumulates in the ageing brain and leads to cognitive decline, impaired motor skills and increased susceptibility to neurodegenerative diseases. Finally, we examine the evidence on the effects of exercise on neuronal myelination in the central nervous system, a crucial factor in maintaining brain health throughout the lifespan.

Osteoarthritis (OA) is the most prevalent degenerative joint disease worldwide, imposing a substantial global disease burden. However, its pathogenesis remains incompletely understood, and effective treatment strategies are still lacking. Organoid technology, in which stem cells or progenitor cells self-organise into miniature tissue structures under three-dimensional (3D) culture conditions, provides a promising in vitro platform for simulating the pathological microenvironment of OA. This approach can be employed to investigate disease mechanisms, carry out high-throughput drug screening and facilitate personalised therapies. This review summarises joint structure, OA pathogenesis and pathological manifestations, thereby establishing the disease context for the application of organoid technology. It then examines the components of the arthrosis organoid system, specifically addressing cartilage, subchondral bone, synovium, skeletal muscle and ligament organoids. Furthermore, it details various strategies for constructing OA organoids, including considerations of cell selection, pathological classification and fabrication techniques. Notably, this review introduces the concept of intelligent manufacturing of OA organoids by incorporating emerging engineering technologies such as artificial intelligence (AI) into the organoid fabrication process, thereby forming an innovative software and hardware cluster. Lastly, this review discusses the challenges currently facing intelligent OA organoid manufacturing and highlights future directions for this rapidly evolving field. By offering a comprehensive overview of state-of-the-art methodologies and challenges, this review anticipates that intelligent, automated fabrication of OA organoids will expedite fundamental research, drug discovery and personalised translational applications in the orthopaedic field.

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer mortality. Despite advancements in gene targeted therapies and immunotherapies, high heterogeneity contributes to limited efficacy and therapeutic resistance. Ubiquitination, a crucial post-translational modification that regulates protein stability and degradation, plays a significant role in cancer pathogenesis by influencing key oncogenic pathways and tumour progression. This review systematically explores the ubiquitin-proteasome system (UPS) and its potential as a therapeutic target for NSCLC. We highlight recent preclinical and clinical studies focusing on ubiquitination-related biomarkers, drug targets and emerging therapies like proteasome inhibitors and Proteolysis-targeting chimeras (PROTACs). By exploring the impact of the UPS on tumour biology, the progression of NSCLC and its response to therapy, we aim to underscore the potential of targeting the ubiquitination-deubiquitination system as a complementary or synergistic approach to existing therapeutic strategies in NSCLC, thereby enhancing patient outcomes and overcoming treatment resistance.