Yanhu Li

Current therapeutic strategies for intervertebral disc degeneration (IDD)-related low back pain are limited to symptomatic alleviation. Notochordal cells (NCs), as progenitor cells of the nucleus pulposus (NP), lead us to develop innovative NC-based new therapies for IDD. A total of 40 NP specimens, obtained according to IDD criteria with defined Pfirrmann grades and histological degeneration score, were categorized as either normal (Grade II) or degenerated (Grade IV). An IDD model was established in SD rats by needle puncture of the annulus fibrosus. Degenerated NP tissue was identified using MRI, H&E, Safranin O, and Masson staining. NCs and NP cells (NPCs) were isolated and identified based on specific cellular markers. Furthermore, mRNA-seq was performed to profile gene expression in these cells. GO annotation and KEGG pathway analysis were employed to perform functional enrichment analysis of the differentially expressed genes (DEGs). Cell viability was assessed using the CCK-8 assay. An in vitro cell degeneration model was established by treating NPCs with TBHP. Analysis of specific marker expression was performed using Western blotting, immunohistochemistry, and immunofluorescence. We found that the number of NCs in degenerated NP tissues was significantly reduced compared to those in normal NP tissues, but a small amount of notochordal cell markers could still be detected. Analysis of sequencing data identified 2391 upregulated and 3813 downregulated DEGs. GO enrichment analysis indicated that these DEGs were significantly associated with regulatory signals including cellular senescence and oxidative stress. KEGG pathway analysis further revealed that the DEGs were primarily enriched in the TNF and HIF-1 signaling pathways. Subsequent screening identified the top 10 key genes potentially related to IDD: Sod2, Cxcl12, Spp1, Fn1, Cat, Il6, Ccl2, Igf1, Fgf2, and Acta2. Collectively, our findings establish a clear link between SOD2/CAT and the pathogenesis of IDD. SOD2 and CAT may serve as promising new potential therapeutic targets for IDD by inhibiting oxidative stress and cellular senescence in NPCs.

In recent years, a growing number of studies have disclosed the substantial role of macrophages—key immune cells—in the pathological process of intervertebral disc degeneration. Researchers have categorised macrophage phenotypes into M1 and M2 polarisation, associating these polarisations with intervertebral disc degeneration. Essentially, macrophage phenotypes can be classified as either pro‐inflammatory or anti‐inflammatory. Induced by diverse factors, these distinct polarisation states exert contrary effects on disc injury and repair. Although numerous studies focus on the polarisation of macrophages and the cytokines they secrete in relation to intervertebral disc degeneration, these studies frequently neglect the relationship between the efferocytosis of macrophages and the progression of intervertebral disc degeneration. Efferocytosis is a specialised procedure in which phagocytes, such as macrophages, engulf and eliminate apoptotic cells. This process is crucial for maintaining tissue homeostasis and resolving inflammation. By effectively clearing these dying cells, efferocytosis helps prevent the release of potentially detrimental cellular contents, thereby facilitating healing and the resolution of inflammation. Simultaneously, macrophages digest the engulfed cell debris and release various cytokines that participate in tissue self‐repair. Therefore, this article presents an overview of the molecular mechanisms connecting macrophages and their efferocytosis activity to intervertebral disc degeneration, explores new directions for the utilisation of macrophages in the treatment of intervertebral disc degeneration, and discusses the future prospects for the development of therapeutic targets.

SLC7A11 plays a pivotal role in tumour development by facilitating cystine import to enhance glutathione synthesis and counteract oxidative stress. Disulphidptosis, an emerging form of cell death observed in cells with high expression of SLC7A11 under glucose deprivation, is regulated through reduction–oxidation reactions and disulphide bond formation. This process leads to contraction and collapse of the F‐actin cytoskeleton from the plasma membrane, ultimately resulting in cellular demise. Compared to other forms of cell death, disulphidptosis exhibits distinctive characteristics and regulatory mechanisms. This mechanism provides novel insights and innovative strategies for cancer treatment while also inspiring potential therapeutic approaches for other diseases. Our review focuses on elucidating the molecular mechanism underlying disulphidptosis and its connection with the actin cytoskeleton, identifying alternative metabolic forms of cell death, as well as offering insights into disulphidptosis‐based cancer therapy. A comprehensive understanding of disulphidptosis will contribute to our knowledge about fundamental cellular homeostasis and facilitate the development of groundbreaking therapies for disease treatment.

Intervertebral disc degeneration (IDD) is a prevalent musculoskeletal degenerative disorder worldwide, and ~40% of chronic low back pain cases are associated with IDD. Although the pathogenesis of IDD remains unclear, the reduction in nucleus pulposus cells (NPCs) and degradation of the extracellular matrix (ECM) are critical factors contributing to IDD. Notochordal cells (NCs), derived from the notochord, which rapidly degrades after birth and is eventually replaced by NPCs, play a crucial role in maintaining ECM homeostasis and preventing NPCs apoptosis. Current treatments for IDD only provide symptomatic relief, while lacking the ability to inhibit or reverse its progression. However, NCs and their secretions possess anti‐inflammatory properties and promote NPCs proliferation, leading to ECM formation. Therefore, in recent years, NCs therapy targeting the underlying cause of IDD has emerged as a novel treatment strategy. This article provides a comprehensive review of the latest research progress on NCs for IDD, covering their biological characteristics, specific markers, possible mechanisms involved in IDD and therapeutic effects. It also highlights significant future directions in this field to facilitate further exploration of the pathogenesis of IDD and the development of new therapies based on NCs strategies.

A series of blue-light-emitting conjugated polymers that possess high-lying HOMO energy levels were synthesized by introducing trifluoren-2-yl-amine (TFA) as a building block. The emission color could be effectively tuned in the region of deep-blue and light-blue by introducing various substituents onto the TFA as the pendants. Deep-blue light emission was achieved for the device based on P4FNCz as an emitting layer without using any hole-transport layer (HTL), giving a maximum current efficiency (CE) of 2.44 cd A⁻¹, corresponding to an external quantum efficiency of 3.00%, with Commission Internationale de L'Eclairage (CIE) coordinates of (0.16, 0.12). Thanks to the improved hole injection and transport ability, red- and green-light-emitting devices based on P4FNCz as an HTL were also successfully fabricated, giving a maximum CE of 7 and 25 cd A⁻¹ with CIE coordinates of (0.64, 0.34) and (0.29, 0.64), respectively, which are comparable to those of the devices based on a general HTL of 4,4′-bis(N-(1-naphthyl)-N-phenylamino)biphenyl (NPB). The CIE coordinates of the RGB devices are very close to those of the National Television System Committee (NTSC) and High Definition Television (HDTV) standard colors. The RGB devices achieved by tuning the carrier recombination zone with different electron-transport layers will facilitate the development of the polymer-based full-color flat-panel displays in an alternative process.