Osteoarthritis(OA)is a highly incident total joint degenerative disease with cartilage degeneration as the primary pathogenesis.The cartilage matrix is mainly composed of collagen,a matrix protein with a hallmark triplehelix structure,which unfolds with collagen degradation on the cartilage surface.A collagen hybridizing peptide(CHP)is a synthetic peptide that binds the denatured collagen triple helix,conferring a potential diseasetargeting possibility for early-stage OA.Here,we constructed an albumin nanoparticle(An)conjugated with CHP,loaded with a chondrogenesis-promoting small molecule drug,kartogenin(KGN).The CHP-KGN-An particle exhibited sustained release of KGN in vitro and prolonged in vivo retention selectively within the degenerated cartilage in the knee joints of model mice with early-stage OA.Compared to treatment with KGN alone,CHP-KGN-An robustly attenuated cartilage degradation,synovitis,osteophyte formation,and subchondral bone sclerosis in OA model mice and exhibited a more prominent effect on physical activity improvement and pain alleviation.Our study showcases that targeting the degenerated cartilage by collagen hybridization can remarkably promote the efficacy of small molecule drugs and may provide a novel delivery strategy for earlystage OA therapeutics.
The hallmarks of spondyloarthritis(SpA)are type 3 immunity-driven inflammation and new bone formation(NBF).Macrophage migration inhibitory factor(MIF)was found to be a key driver of the pathogenesis of SpA by amplifying type 3 immunity,yet MIF-interacting molecules and networks remain elusive.Herein,we identified hypoxia-inducible factor-1 alpha(HIF1A)as an interacting partner molecule of MIF that drives SpA pathologies,including inflammation and NBF.HIF1A expression was increased in the joint tissues and synovial fluid of SpA patients and curdlan-injected SKG(curdlan-SKG)mice compared to the respective controls.Under hypoxic conditions in which HIF1A was stabilized,human and mouse neutrophils exhibited substantially increased expression of MIF and IL-23,an upstream type 3 immunity-related cytokine.Similar to MIF,systemic overexpression of IL-23 induced SpA pathology in SKG mice,while the injection of a HIF1A-selective inhibitor(PX-478)into curdlan-SKG mice prevented or attenuated SpA pathology,as indicated by a marked reduction in the expression of MIF and IL-23.Furthermore,genetic deletion of MIF or HIF1A inhibition with PX-478 in IL-23-overexpressing SKG mice did not induce evident arthritis or NBF,despite the presence of psoriasis-like dermatitis and blepharitis.We also found that MIF-and IL-23-expressing neutrophils infiltrated areas of the NBF in curdlan-SKG mice.These neutrophils potentially increased chondrogenesis and cell proliferation via the upregulation of STAT3 in periosteal cells and ligamental cells during endochondral ossification.Together,these results provide supporting evidence for an MIF/HIF1A regulatory network,and inhibition of HIF1A may be a novel therapeutic approach for SpA by suppressing type 3 immunity-mediated inflammation and NBF.
Utilizing transplanted human umbilical cord mesenchymal stem cells(HUMSCs)for cartilage defects yielded advanced tissue regeneration,but the underlying mechanism remain elucidated.Early after HUMSCs delivery to the defects,we observed substantial apoptosis.The released apoptotic vesicles(apoVs)of HUMSCs promoted cartilage regeneration by alleviating the chondro-immune microenvironment.ApoVs triggered M2 polarization in macrophages while simultaneously facilitating the chondrogenic differentiation of endogenous MSCs.Mechanistically,in macrophages,miR-100-5p delivered by apoVs activated the MAPK/ERK signaling pathway to promote M2 polarization.In MSCs,let-7i-5p delivered by apoVs promoted chondrogenic differentiation by targeting the eEF2K/p38 MAPK axis.Consequently,a cell-free cartilage regeneration strategy using apoVs combined with a decellularized cartilage extracellular matrix(DCM)scaffold effectively promoted the regeneration of osteochondral defects.Overall,new mechanisms of cartilage regeneration by transplanted MSCs were unconcealed in this study.Moreover,we provided a novel experimental basis for cell-free tissue engineering-based cartilage regeneration utilizing apoVs.Utilizing transplanted human umbilical cord mesenchymal stem cells(HUMSCs)for cartilage defects yielded advanced tissue regeneration,but the underlying mechanism remain elucidated.Early after HUMSCs delivery to the defects,we observed substantial apoptosis.The released apoptotic vesicles(apoVs)of HUMSCs promoted cartilage regeneration by alleviating the chondro-immune microenvironment.ApoVs triggered M2 polarization in macrophages while simultaneously facilitating the chondrogenic differentiation of endogenous MSCs.Mechanistically,in macrophages,miR-100-5p delivered by apoVs activated the MAPK/ERK signaling pathway to promote M2 polarization.In MSCs,let-7i-5p delivered by apoVs promoted chondrogenic differentiation by targeting the eEF2K/p38 MAPK axis.Consequently,a cell-free cartilage regeneration strategy using apoVs combined with a decel
2024年3月7日,北京大学药学院天然药物及仿生药物全国重点实验室王坚成教授/朱元军博士团队和北京大学第三医院运动医学江东主任医师团队共同在国际学术期刊ACS Nano在线发表了题为“Nanomedicines Promote Cartilage Regeneration in Osteoarthritis by Synergistically Enhancing Chondrogenesis of Mesenchymal Stem Cells and Regulating Inflammatory Environment”的研究论文。该研究提出了碳酸酐酶IX siRNA(siCA9)调控炎症微环境调控促进Kartogenin(KGN)诱导的间充质干细胞(MSCs)软骨定向分化作用的新策略,显著提高了MSCs在骨关节炎(OA)治疗中的软骨再生能力,改善了晚期OA治疗效应。
DEAR EDITOR,Sox9 is a member of the Sry-related high-mobility group box(Sox)transcription factor family in animals.In teleost fish,Sox9 undergoes duplication to generate two duplicates,namely Sox9a and Sox9b.However,the functions of these duplicates in the teleost Nile tilapia(Oreochromis niloticus)remain unclear.In this study,we characterized the roles of Nile tilapia Sox9a in chondrogenesis and gonadal development.In situ hybridization assays showed that Sox9a was mainly expressed in cartilage tissues and somatic cells surrounding germ cells of the gonads.CRISPR/Cas9-mediated homozygous mutation of the Sox9a gene resulted in craniofacial deformities and missed mandibles,as well as impaired the expression of Col2a1a that is involved in chondrogenesis.In addition,germ cell number and DNA replication in somatic cells in the gonads of both sexes were reduced following Sox9a mutation.Taken together,this study demonstrates that Sox9a is involved in cartilage development and germ cell proliferation in Nile tilapia.
