Project description:Objectives: Articular cartilage damage has become a universal health burden. Despite the recent progresses in cell-based cartilage regeneration, chondrocyte dedifferentiation has compromised the clinical outcomes, which is frequently seen in chondrocyte expansion and osteoarthritis, involving functional phenotype loss. However, its concept remains elusive with unknown intermediate process and mechanisms. Here we demonstrated a time-lapse atlas of chondrocyte dedifferentiation, to provide molecular details and informative biomarkers for clinical chondrocyte evaluation. Methods: Single-cell RNA sequencing (scRNA-seq) was employed to dissect the chondrocyte dedifferentiation and identify distinct cellular subpopulations. To validate the findings, live-cell metabolic assay, high-resolution imaging and ¡°assay for transposase-accessible chromatin with high throughput sequencing¡± (ATAC-seq) were conducted. Using a chemical inhibitor BTB06584 affecting on mitochondrial F1F0ATPase, we revealed the recovery potential of early and late dedifferentiated chondrocytes. Results:Our findings shape a biphasic model consist of early and late dedifferentiation stages. Early dedifferentiated chondrocytes uniquely obtained a transient glycolytic phenotype with an activation of metabolic and anti-oxidant genes; late dedifferentiated chondrocytes exhibited ultrastructural changes including mitochondrion damages and stress-associated chromatin remodeling. Using a chemical inhibitor BTB06584, we revealed that early and late dedifferentiated chondrocytes possessed distinguished recovery potential from functional phenotype loss. BTB06584 treatment ameliorated early phenotype loss through inhibiting MAPK pathway. Notably, this two-stage transition was validated in human chondrocyte culture. An image-based approach was established for clinical utilization, to efficiently predict chondrocytes plasticity with stage-specific biomarkers. Conclusion: Thus this study lays a foundation for future clinical chondrocyte quality regulation and provides insights for deeper understanding of chondrocyte dedifferentiation.

Project description:Background: Sepsis involves aberrant immune responses to infection, but the exact nature of this immune dysfunction remains poorly defined. Bacterial endotoxins like lipopolysaccharide (LPS) are potent inducers of inflammation, which has been associated with the pathophysiology of sepsis, but repeated exposure can also induce a suppressive effect known as endotoxin tolerance or cellular reprogramming. It has been proposed that endotoxin tolerance might be associated with the immunosuppressive state that was primarily observed during late-stage sepsis. However, this relationship remains poorly characterised. Here we clarify the underlying mechanisms and timing of immune dysfunction in sepsis. Methods: We defined a gene expression signature characteristic of endotoxin tolerance. Gene-set test approaches were used to correlate this signature with early sepsis, both newly and retrospectively analysing microarrays from 593 patients in 11 cohorts. Then we recruited a unique cohort of possible sepsis patients at first clinical presentation in an independent blinded controlled observational study to determine whether this signature was associated with the development of confirmed sepsis and organ dysfunction. Findings: All sepsis patients presented an expression profile strongly associated with the endotoxin tolerance signature (p < 0.01; AUC 96.1%). Importantly, this signature further differentiated between suspected sepsis patients who did, or did not, go on to develop confirmed sepsis, and predicted the development of organ dysfunction. Interpretation: Our data support an updated model of sepsis pathogenesis in which endotoxin tolerance-mediated immune dysfunction (cellular reprogramming) is present throughout the clinical course of disease and related to disease severity. Thus endotoxin tolerance might offer new insights guiding the development of new therapies and diagnostics for early sepsis. For the RNA-Seq study reported here, 73 patients were recruited with deferred consent at the time of first examination in an emergency ward based on the opinion of physicians that there was a potential for the patient's condition to develop into sepsis. These were retrospectively divided into groups based on clinical features and compared to 11 non-urgent surgical controls.

			Action	DRS
	ERR5023090_1.fastq.gz	Fastqsanger.gz
	ERR5023090_2.fastq.gz	Fastqsanger.gz
	ERR5023100_1.fastq.gz	Fastqsanger.gz
	ERR5023100_2.fastq.gz	Fastqsanger.gz
	ERR5023110_1.fastq.gz	Fastqsanger.gz

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Dental_Implant_Failure

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