RESUMO
Degenerative bone disorders have a significant impact on global health, and regeneration of articular cartilage remains a challenge. Existing cell therapies using mesenchymal stromal cells (MSCs) have shown limited efficacy, highlighting the necessity for alternative stem cell sources. Here, we have identified and characterized MSX1+ mesenchymal progenitor cells in the developing limb bud with remarkable osteochondral-regenerative and microenvironment-adaptive capabilities. Single-cell sequencing further revealed the presence of two major cell compositions within the MSX1+ cells, where a distinct PDGFRAlow subset retained the strongest osteochondral competency and could efficiently regenerate articular cartilage in vivo. Furthermore, a strategy was developed to generate MSX1+PDGFRAlow limb mesenchyme-like (LML) cells from human pluripotent stem cells that closely resembled their mouse counterparts, which were bipotential in vitro and could directly regenerate damaged cartilage in a mouse injury model. Together, our results indicated that MSX1+PDGFRAlow LML cells might be a prominent stem cell source for human cartilage regeneration.
Assuntos
Cartilagem Articular , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Humanos , Camundongos , Animais , Células-Tronco , Terapia Baseada em Transplante de Células e Tecidos , Mesoderma , Transplante de Células-Tronco Mesenquimais/métodos , Diferenciação Celular , Fator de Transcrição MSX1/genéticaRESUMO
NOD-like receptors (NLRs) are traditionally recognized as major inflammasome components. The role of NLRs in germ cell differentiation and reproduction is not known. Here, we identified the gonad-specific Nlrp14 as a pivotal regulator in primordial germ cell-like cell (PGCLC) differentiation in vitro. Physiologically, knock out of Nlrp14 resulted in reproductive failure in both female and male mice. In adult male mice, Nlrp14 knockout (KO) inhibited differentiation of spermatogonial stem cells (SSCs) and meiosis, resulting in trapped SSCs in early stages, severe oligozoospermia, and sperm abnormality. Mechanistically, NLRP14 promoted spermatogenesis by recruiting a chaperone cofactor, BAG2, to bind with HSPA2 and form the NLRP14-HSPA2-BAG2 complex, which strongly inhibited ChIP-mediated HSPA2 polyubiquitination and promoted its nuclear translocation. Finally, loss of HSPA2 protection and BAG2 recruitment by NLRP14 was confirmed in a human nonsense germline variant associated with male sterility. Together, our data highlight a unique proteasome-mediated, noncanonical function of NLRP14 in PGCLC differentiation and spermatogenesis, providing mechanistic insights of gonad-specific NLRs in mammalian germline development.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Diferenciação Celular/fisiologia , Proteínas de Choque Térmico HSP70/metabolismo , Chaperonas Moleculares/metabolismo , Espermatogênese/genética , Transporte Ativo do Núcleo Celular/genética , Transporte Ativo do Núcleo Celular/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Células-Tronco Germinativas Adultas/fisiologia , Animais , Proteínas Reguladoras de Apoptose/genética , Feminino , Deleção de Genes , Regulação da Expressão Gênica/fisiologia , Variação Genética , Células Germinativas , Proteínas de Choque Térmico HSP70/genética , Humanos , Infertilidade Masculina/genética , Masculino , Camundongos , Chaperonas Moleculares/genética , Nucleosídeo-Trifosfatase/genética , Nucleosídeo-Trifosfatase/metabolismo , Espermatogênese/fisiologiaRESUMO
OBJECTIVE: To evaluate the sterilization effect of new designed atmospheric low temperature plasma jet on Candida albicans ( C. albicans) biofilm. METHODS: C. albicans was grown into the logarithmic phase, and then was added to polystyrene 24-well microtitre plate. The amount of germs were calculated by viable plate counting to determine the reproducibility of each biofilm well. The germs in biofilm were treated by plasma for different exposure time and then the survived germs were quantified by plate counting, the dead cells were determined by staining the biofilm with propidium iodide (PI), and the ultrastructural changes of the germs in biofilm were observed by transmission electron microscopy (TEM). RESULTS: When incubated for 72 h, germs tightly polymerized and classical mature biofilm were formed. This atmospheric low temperature plasma jet could inactivate C. albicans biofilm within a short exposure time. C. albicans were 90% inactivated when treated 20 s and 55 s of plasma treatment reduced bacteria populations to undetectable levels. With the increase of treatment time, enlarged fluorescent positive area appeared, and more bacteria died with the extending of exposure. The TEM scanning results showed that the new plasma jet inactivated C. albicans biofilm mainly via disrupting cell envelopes and then leading the release of cellular components, thus resulting in loss of cell viability. CONCLUSION: Plasma generated from atmospheric low temperature plasma jet could damage the cell structure of C. albicans and efficiently sterilize C. albicans biofilm.
