BACKGROUND:Bone marrow mesenchymal stem cells possess multipotent differentiation potential and are an important source of cells for cartilage and bone tissue regeneration research.Kartogenin is a small-molecule drug that has been demonstrated to promote stem cell differentiation towards chondrogenesis.However,the ability to promote osteogenic differentiation is still controversial,and the specific effects of kartogenin on the chondrogenic and osteogenic differentiation of stem cells of different species have not been fully elucidated.OBJECTIVE:To investigate the effects of kartogenin on chondrogenic and osteogenic differentiation in rabbit-derived and rat-derived bone marrow mesenchymal stem cells.METHODS:Rabbit-derived and rat-derived bone marrow mesenchymal stem cells were obtained through whole bone marrow separation and adherence methods,and were treated with varying concentrations of kartogenin.Cell proliferation was detected using the CCK-8 assay.Chondrogenic and osteogenic differentiation was assessed via toluidine blue and alizarin red staining,respectively.After screening for the optimal concentration of kartogenin,alkaline phosphatase staining,qRT-PCR,and western blot assay were employed to analyze the expression of osteogenic and chondrogenic-related genes and proteins.RESULTS AND CONCLUSION:(1)Within the concentration range of 0 to 10 000 nmol/L,kartogenin did not significantly affect the proliferation of rabbit-derived or mouse-derived bone marrow mesenchymal stem cells.(2)The differentiation effect of kartogenin on rabbit-derived and rat-derived bone marrow mesenchymal stem cells showed significant differences.In rabbit-derived bone marrow mesenchymal stem cells,kartogenin predominantly promoted chondrogenic differentiation while inhibiting osteogenic differentiation.This was evident from positive toluidine blue staining,whereas alkaline phosphatase and alizarin red staining exhibited no significant changes.qRT-PCR analysis revealed upregulation of chondrogenic-related genes(Col2a1 and Sox9)and downregulation of genes associated with osteogenesis(Alpl,Col1a1,Runx2,and Bglap).Similar results were found in the western blot assay.(3)In contrast,kartogenin in mouse-derived bone marrow mesenchymal stem cells promoted both chondrogenic and osteogenic differentiation.While toluidine blue staining remained largely unchanged,alkaline phosphatase and alizarin red staining revealed increased positivity,indicative of enhanced osteogenesis.qRT-PCR analysis showed upregulation of not only chondrogenic-related genes(Col2a1 and Sox9)but also genes linked to osteogenesis(Alpl,Col1a1,Runx2,and Bglap).The western blot assay results showed similar results.These findings suggest that kartogenin exerts differential regulatory effects on the differentiation of rabbit and rat bone marrow mesenchymal stem cells,potentially stemming from variations in gene expression profiles and underlying signaling pathways.

BACKGROUND:Bone marrow mesenchymal stem cells possess multipotent differentiation potential and are an important source of cells for cartilage and bone tissue regeneration research.Kartogenin is a small-molecule drug that has been demonstrated to promote stem cell differentiation towards chondrogenesis.However,the ability to promote osteogenic differentiation is still controversial,and the specific effects of kartogenin on the chondrogenic and osteogenic differentiation of stem cells of different species have not been fully elucidated.OBJECTIVE:To investigate the effects of kartogenin on chondrogenic and osteogenic differentiation in rabbit-derived and rat-derived bone marrow mesenchymal stem cells.METHODS:Rabbit-derived and rat-derived bone marrow mesenchymal stem cells were obtained through whole bone marrow separation and adherence methods,and were treated with varying concentrations of kartogenin.Cell proliferation was detected using the CCK-8 assay.Chondrogenic and osteogenic differentiation was assessed via toluidine blue and alizarin red staining,respectively.After screening for the optimal concentration of kartogenin,alkaline phosphatase staining,qRT-PCR,and western blot assay were employed to analyze the expression of osteogenic and chondrogenic-related genes and proteins.RESULTS AND CONCLUSION:(1)Within the concentration range of 0 to 10 000 nmol/L,kartogenin did not significantly affect the proliferation of rabbit-derived or mouse-derived bone marrow mesenchymal stem cells.(2)The differentiation effect of kartogenin on rabbit-derived and rat-derived bone marrow mesenchymal stem cells showed significant differences.In rabbit-derived bone marrow mesenchymal stem cells,kartogenin predominantly promoted chondrogenic differentiation while inhibiting osteogenic differentiation.This was evident from positive toluidine blue staining,whereas alkaline phosphatase and alizarin red staining exhibited no significant changes.qRT-PCR analysis revealed upregulation of chondrogenic-related genes(Col2a1 and Sox9)and downregulation of genes associated with osteogenesis(Alpl,Col1a1,Runx2,and Bglap).Similar results were found in the western blot assay.(3)In contrast,kartogenin in mouse-derived bone marrow mesenchymal stem cells promoted both chondrogenic and osteogenic differentiation.While toluidine blue staining remained largely unchanged,alkaline phosphatase and alizarin red staining revealed increased positivity,indicative of enhanced osteogenesis.qRT-PCR analysis showed upregulation of not only chondrogenic-related genes(Col2a1 and Sox9)but also genes linked to osteogenesis(Alpl,Col1a1,Runx2,and Bglap).The western blot assay results showed similar results.These findings suggest that kartogenin exerts differential regulatory effects on the differentiation of rabbit and rat bone marrow mesenchymal stem cells,potentially stemming from variations in gene expression profiles and underlying signaling pathways.

Degenerative disc disease (DDD) is a leading cause of low back pain, which severely affects the quality of life and incurs significant medical cost. Annulus fibrosus(AF) injuries can lead to substantial deterioration of intervertebral disc degeneration. However, the AF repair/regeneration remains a challenge due to the intrinsic cellular, biochemical and biomechanical heterogeneity of AF tissue. Tissue engineering would be a promising approach for AF regeneration. This article aims to provide a brief overview of the fundamental aspects of AF, the current achievements and future challenges of AF tissue engineering. A multidisciplinary approach is proposed for future studies to fully mimic the native AF tissue and its microenvironment, including choosing adequate cell source, preparing scaffolds with hierarchical microstructures, supplementing appropriate growth factors, and enforcing suitable mechanical stimulation. Hopefully, the engineered AF tissues would be effectively used to facilitate the treatment of DDD in the future.
Humans ; Intervertebral Disc ; growth & development ; Intervertebral Disc Degeneration ; therapy ; Regeneration ; Tissue Engineering

Methylation of histone by protein arginine methyltransferases (PRMTs) plays an important role in gene regulation. PRMT1- and PRMT4-catalyzed methyl-arginine is involved in transcription activation, while PRMT5- and PRMT6-catalyzed methyl-arginine is associated with transcription repression. Histone arginine methylation can be dynamically regulated in vivo, and methyl-arginine is demethylated by "arginine demethylase". Here, the most recent progresses in the methylation studies of histone arginine were summarized.