摘要: We aimed to investigate the role of renal pericyte pyruvate kinase M2 (PKM2) in the progression of acute kidney injury (AKI) to chronic kidney disease (CKD). The role of PKM2 in renal pericyte-myofibroblast transdifferentiation was investigated in an AKICKD mouse model. Platelet growth factor receptor beta (PDGFR beta)-iCreERT2; tdTomato mice were used for renal pericyte tracing. Western blotting and immunofluorescence staining were used to examine protein expression. An 5-ethynyl-20-deoxyuridine assay was used to measure renal pericyte proliferation. A scratch cell migration assay was used to analyse cell migration. Seahorse experiments were used to examine glycolytic rates. Enzyme-linked immunoassay was used to measure pyruvate kinase enzymatic activity and lactate concentrations. The PKM2 nuclear translocation inhibitors Shikonin and TEPP-46 were used to alter pericyte transdifferentiation. In AKI-CKD, renal pericytes proliferated and transdifferentiated into myofibroblasts and PKM2 is highly expressed in renal pericytes. Shikonin and TEPP-46 inhibited pericyte proliferation, migration, and pericyte-myofibroblast transdifferentiation by reducing nuclear PKM2 entry. In the nucleus, PKM2 promoted downstream lactate dehydrogenase A (LDHA) and glucose transporter 1 (GLUT1) transcription, which are critical for glycolysis. Therefore, PKM2 regulates pericyte glycolytic and lactate production, which regulates renal pericytemyofibroblast transdifferentiation. PKM2-regulated renal pericyte-myofibroblast transdifferentiation by regulating downstream LDHA and GLUT1 transcription and lactate production. Reducing nuclear PKM2 import can reduce renal pericytes-myofibroblasts transdifferentiation, providing new ideas for AKI-CKD treatment.

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摘要: Sinusoidal capillarization - key symptoms of liver fibrosis progression - represents potential therapeutic targets. tRNA modification-mediated tRNA-derived small RNAs (tsRNAs) play a role in angiogenesis. NSun2, an RNA methyltransferase, generates a significant number of tsRNAs. However, the role of NSun2 and its mediated tsRNAs in liver fibrosis remains unclear. In this study, NSun2 deficiency was found to inhibit sinusoidal capillarization, alleviating liver fibrosis. Furthermore, endothelial cell angiogenesis and migration were disrupted in NSun2 knockout mice. Mechanistically, reduced NSun2 expression led to alterations in the functional tsRNAs tRF-1-S25 and tRF-5-V31, which regulate sinusoidal capillarization by targeting key proteins, including DUSP1 and FAK - crucial clinical targets. Moreover, intravenous injection of tRF-1-S25 and tRF-5-V31 inhibitor rescued liver fibrosis in mice. In conclusion, tsRNAs generated by NSun2-mediated modification of tRNAs inhibit sinusoidal capillarization. Furthermore, targeting the DUSP1/FAK/p-FAK pathway offers an innovative approach to treat this disease.

摘要: Ribosome biogenesis occurs within the nucleolus, with the initial step being the transcription of ribosomal DNA (rDNA). Although rDNA transcription is limited in somatic cells, it is more active in stem cells. Nevertheless, the mechanisms involved in somatic cell reprogramming remain elusive. Both somatic and stem cell nucleoli exhibit a reticular structure. However, under the electron microscope, we identified an intermediate nucleolar state during reprogramming. This state underwent changes characterised by rDNA hypertranscription, resulting in an enlarged nucleolus, enhanced activity of nucleolus organiser regions (NORs), and a transition from the reticular nucleolar type to an intermediate state of reprogramming, whose three liquid phase boundaries are blurred. Our research revealed that Oct4 was directly targeted to the rDNA enhancer region, promoting its hypertranscription and nucleolar enlargement during reprogramming. Using rDNA transcriptional inhibitors, we proved that nucleolar remodelling and subsequent reprogramming are halted by inhibiting rDNA transcription. But why could rDNA transcriptional activity influence reprogramming? Our findings elucidate that the active nucleoli have the capability to release perinucleolar heterochromatin. By joint analysis of Assay for Transposase-Accessible Chromatin with high throughput sequencing (ATAC-seq) and RNA-seq, we have characterised the perinucleolar chromatin released by the nucleolus in a reprogramming intermediate state. The released chromatin mainly impacted mesenchymal-to-epithelial transition (MET)-related genes. MET is a stage of silencing of mesenchymal genes, accompanied by the activation of epithelial genes. Concurrently, the morphology of mouse embryonic fibroblast cells (MEFs) transitions from elongated spindle-shaped cells to short roundish forms, exhibiting a propensity to cluster together. MET was considered an early event in reprogramming; our findings suggested that nucleolar remodelling occurred before MET.

摘要: 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.

摘要: Liver transplantation is currently the sole definitive treatment option for end-stage liver failure. However, a significant shortage of donors prevails due to high clinical demands. Recently, human liver organoids have shown significant potential in regenerative medicine for liver diseases. Nevertheless, current static cultures of organoids grown in well-plates heavily rely on extracellular matrix hydrogels (Matrigel), thereby limiting both the scalability and quantity of organoid culture. In this study, we present a groundbreaking culture mode that eliminates all reliance on extracellular matrix hydrogels, enabling the successful preparation of functional human liver ductal organoids (LDOs) based on the cell suspension culture mode in a mechanically stirred bioreactor. Initially, the developed suspension culture in a 6-well plate without matrigel was proven to support robust growth of liver ductal organoids with an average size 2.6 times larger than those obtained in static culture, and with a high organoid survival rate exceeding 90%. Also, the transcriptome profile reveals that suspension culture activates the phosphatidylinositol 3-kinase (PI3K) signalling pathway through mechanical signal transduction, thereby promoting hepatobiliary characteristics. Then, a controllable and scalable bioprocess for liver ductal organoid culture was developed and successfully scaled up to a 50 mL flask bioreactor with a working volume of 15 mL. Finally, animal experiments indicated that the transplantation of liver ductal organoids harvested from suspension culture can effectively alleviate liver injury and inflammation, demonstrating the feasibility of large-scale production of liver ductal organoids cultivated in suspension culture with an improved extracellular matrix environment.

摘要: The intricate mechanisms driving oocyte maturation remain only partially understood, especially within the domains of domestic animal reproduction and translational medicine. In the case of prepubertal girls, the clinical challenge is especially pronounced, as ovarian tissue cryopreservation-though promising-remains an experimental technique necessitating rigorous scientific validation to guarantee the developmental potential of preserved materials and facilitate broader clinical adoption. To address these knowledge gaps, while considering the ethical implications, we applied transcriptome and translatome sequencing to comprehensively profile the transcriptional and translational dynamics of oocyte maturation in adult and prepubertal goats. Our analyses uncovered a sequential transition in gene expression regulation, shifting from cytoplasmic processes to chromosome segregation during the maturation process. Comparative profiling between adult and prepubertal goat oocytes revealed critical regulatory factors essential for prepubertal oocyte maturation. These include genes involved in organelle function (GTPBP4 and TOMM7), spindle organisation (CKS2, CCP110, CKAP5 and ESCO1) and chromosome segregation (CENPE, CENPF, CENPN and SGO2). Functional validation through in vitro maturation experiments demonstrated that GTPBP4 significantly enhances the developmental competence of prepubertal goat oocytes. This enhancement occurs through mechanisms that promote cell cycle progression, organelle maturation and mRNA translation. These findings provide a detailed map of the molecular events underpinning goat oocyte maturation and offer new perspectives on the developmental strategies required for oocyte competence in prepubertal females. Translating these insights to humans, this research highlights potential fertility preservation strategies for prepubertal girls, such as ovarian tissue cryopreservation and transplantation, in vitro follicle culture, meiotic maturation and artificial ovary technologies. Moreover, the identified mechanisms have significant implications for improving reproductive efficiency in domestic animal breeding, bridging basic research and applied science.

摘要: Spermatogenesis is a highly unique and intricate process, finely regulated at multiple levels, including post-transcriptional regulation. N6-methyladenosine (m6A), the most prevalent internal modification in eukaryotic mRNA, plays a significant role in transcriptional regulation during spermatogenesis. Previous research indicated extensive m6A modification at each stage of spermatogenesis, but depletion of Mettl3 and/or Mettl14 in spermatogenic cells with Stra8-Cre did not reveal any detectable abnormalities up to the stage of elongating spermatids. This suggests the involvement of other methyltransferases in the regulation of m6A modification during spermatogonial differentiation and meiosis. As a METTL3/14-independent m6A methyltransferase, METTL16 remains insufficiently studied in its roles during spermatogenesis. We report that male mice with Mettl16(vasa-cre) exhibited significantly smaller testes, accompanied by a progressive loss of spermatogonia after birth. Additionally, the deletion of Mettl16 in A1 spermatogonia using Stra8-Cre results in a blockade in spermatogonial differentiation. Given YTHDC1's specific recognition for METTL16 target genes, we further investigated the role of YTHDC1 using Ythdc1-sKO mouse model. Our results indicate that Ythdc1(Stra8-cre) also impairs spermatogonial differentiation, similar to the effects observed in Mettl16(Stra8-cre) mice. RNA-seq and m6A-seq analyses revealed that deletion of either Mettl6 or Ythdc1 disrupted the gene expression related to chromosome organisation and segregation, ultimately leading to male infertility. Collectively, this study underscores the essential roles of the m6A writer METTL16 and its reader YTHDC1 in the differentiation of spermatogonia.