摘要: Periodontal ligament stem cells (PDLSCs) are key cells that suppress periodontal damage during both the progression and recovery stages of periodontitis. Although substantial evidence has demonstrated that incubation under an inflammatory condition may accelerate senescence of PDLSCs, whether cellular senescence in response to inflammatory incubation contributes to cell dysfunction remain unexplored. In this study, we first observed inflammation-caused PDLSC senescence in periodontitis based on comparisons of matched patients, and this cellular senescence was demonstrated in healthy cells that were subjected to inflammatory conditions. We subsequently designed further experiments to investigate the possible mechanism underlying inflammation-induced PDLSC senescence with a particular focus on the role of long noncoding RNAs (lncRNAs). LncRNA microarray analysis and functional gain/loss studies revealed SLC30A4-AS1 as a regulator of inflammation-mediated PDLSC senescence. By full-length transcriptome sequencing, we found that SLC30A4-AS1 interacted with SRSF3 to affect the alternative splicing (AS) of TP53BP1 and alter the expression of TP53BP1-204. Further functional studies showed that decreased expression of TP53BP1-204 reversed PDLSC senescence, and SLC30A4-AS1 overexpression-induced PDLSC senescence was abolished by TP53BP1-204 knockdown. Our data suggest for the first time that SLC30A4-AS1 plays a key role in regulating PDLSC senescence in inflammatory environments by modulating the AS of TP53BP1.

摘要: The cell cycle is crucial for maintaining normal cellular functions and preventing replication errors. FOXM1, a key transcription factor, plays a pivotal role in regulating cell cycle progression and is implicated in various physiological and pathological processes, including cancers like liver, prostate, breast, lung and colon cancer. Despite previous research, our understanding of FOXM1 dynamics under different cell cycle perturbations and its connection to heterogeneous cell fate decisions remains limited. In this study, we investigated FOXM1 behaviour in individual cells exposed to various perturbagens. We found that different drugs induce diverse responses due to heterogeneous FOXM1 dynamics at the single-cell level. Single-cell analysis identified six distinct cellular phenotypes: on-time cytokinesis, cytokinesis delay, cell cycle delay, G1 arrest, G2 arrest and cell death, observed across different drug types and doses. Specifically, treatments with PLK1, CDK1, CDK1/2 and Aurora kinase inhibitors revealed varied FOXM1 dynamics leading to heterogeneous cellular outcomes. Our findings affirm that the dynamics of FOXM1 are essential in shaping cellular outcomes, influencing the signals that dictate responses to various stimuli. Our results gave insights into how FOXM1 dynamics contribute to cell cycle fate decisions, especially under different cell cycle perturbations.

摘要: Neurogenesis is the process of generating new neurons from neural stem cells (NSCs) and plays a crucial role in neurological diseases. The process involves a series of steps, including NSC proliferation, migration and differentiation, which are regulated by multiple pathways such as neurotrophic Trk and fibroblast growth factor receptors (FGFR) signalling. Despite the discovery of numerous compounds capable of modulating individual stages of neurogenesis, it remains challenging to identify an agent that can regulate multiple cellular processes of neurogenesis. Here, through screening of bioactive compounds in dietary functional foods, we identified a flavonoid chrysin that not only enhanced the human NSCs proliferation but also facilitated neuronal differentiation and neurite outgrowth. Further mechanistic study revealed the effect of chrysin was attenuated by inhibition of neurotrophic tropomyosin receptor kinase-B (TrkB) receptor. Consistently, chrysin activated TrkB and downstream ERK1/2 and AKT. Intriguingly, we found that the effect of chrysin was also reduced by FGFR1 blockade. Moreover, extended treatment of chrysin enhanced levels of brain-derived neurotrophic factor, as well as FGF1 and FGF8. Finally, chrysin was found to promote neurogenesis in human cerebral organoids by increasing the organoid expansion and folding, which was also mediated by TrkB and FGFR1 signalling. To conclude, our study indicates that activating both TrkB and FGFR1 signalling could be a promising avenue for therapeutic interventions in neurological diseases, and chrysin appears to be a potential candidate for the development of such treatments. In this study, we found a dietary flavonoid, chrysin, cooperatively activated tropomyosin receptor kinase-B and FGFR1 signalling with up-regulation of their endogenous ligands to promote human neurogenesis. image

摘要: 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.

摘要: Gene-edited (GE) pig-to-human xenotransplantation continues to make breakthroughs, but which kind of gene combination is suitable for organ-specific transplantation remains unclear. In this study, we utilised CRISPR/Cas9 gene editing technology, PiggyBac transposon system, and serial somatic cell cloning technology to develop GTKO/CMAHKO/beta 4GalNT2KO/hCD46/hCD55/hCD59/hCD39/hTBM 8 gene-edited cloned (GEC) donor pigs and performed pig-to-non-human primate (NHP) transplantation to evaluate the effectiveness of these GEC pigs. The 8-GEC pigs were obtained by recloning with a 33-day-old 8-GEC fetus with O blood type, which was generated after cell transfection, screening of cell colonies, and somatic cell cloning. Molecular identification at DNA, mRNA, and protein levels confirmed successful 8-gene editing. Three copies of transgenes were identified by droplet digital polymerase chain reaction and whole genome sequencing, which were inserted into the introns of pig RFTN1 and MYO10 genes, as well as the intergenic region between PRLR and LOC110257300 genes of these 8-GEC pigs. The 8-GEC pigs also exhibited the ability of germline transmission when mated with our previously generated 4-GEC male pigs. Moreover, antigen-antibody binding assay and complement-dependent cytotoxicity assay demonstrated that 8-gene editing effectively reduced the immune incompatibility and kidney xenograft from 8-GEC pigs survived for 15 and 17 days in two NHPs, respectively. Postoperatively, the recipient serum antibodies IgA, IgG and IgM, complements C3 and C4, coagulation indicators PT, APTT, TT and FIB, as well as most electrolytes and liver function indicators remained relatively stable. Serum creatinine was normal within 10 days post operation. However, the kidney xenograft developed active antibody-mediated rejection at necropsy, characterised by the deposition of antibodies IgG and IgM, as well as complements C4d, C3c and C5b-C9, infiltration of CD68+ macrophages, and micro-thrombotic embolism of glomerular capillaries, etc. In conclusion, we successfully developed fertile 8-GEC pigs, which effectively alleviated immune rejection and exerted life-supporting kidney function in the recipients.