Ion elemental-optimized layered double hydroxide nanoparticles promote chondrogenic differentiation and intervertebral disc regeneration of mesenchymal stem cells through focal adhesion signaling pathway

Chronic low back pain and dyskinesia caused by intervertebral disc degeneration(IDD)are seriously aggravated and become more prevalent with age.Current clinical treatments do not restore the biological structure and inherent function of the disc.The emergence of tissue engineering and regenerative medicine has provided new insights into the treatment of IDD.We synthesized biocompatible layered double hydroxide(LDH)nanoparticles and optimized their ion elemental compositions to promote chondrogenic differentiation of human umbilical cord mesenchymal stem cells(hUC-MSCs).The chondrogenic differentiation of LDH-treated MSCs was validated using Alcian blue staining,qPCR,and immunofluorescence analyses.LDH-pretreated hUC-MSCs were differentiated prior to transplantation into the degenerative site of a needle puncture IDD rat model.Repair and regeneration evaluated using X-ray,magnetic resonance imaging,and tissue immunostaining 4-12 weeks after transplantation showed recovery of the disc space height and integrated tissue structure.Transcriptome sequencing revealed significant regulatory roles of the extracellular matrix(ECM)and integrin receptors of focal adhesion signaling pathway in enhancing chondrogenic differentiation and thus prompting tissue regeneration.The construction of ion-specific LDH nanomaterials for in situ intervertebral disc regeneration through the focal adhesion signaling pathway provides theoretical basis for clinical transformation in IDD treatment.

Aldolase A promotes proliferation and G1/S transition via the EGFR/MAPK pathway in non-small cell lung cancer

Background:Our previous study demonstrated that aldolase A(ALDOA)is overexpressed in clinical human lung squamous cell carcinoma and that ALDOA promotes epithelial-mesenchymal transition and tumorigenesis.The pre-sent study aimed to explore the function of ALDOA in the modulation of non-small cell lung cancer(NSCLC)prolifera-tion and cell cycle progression and the potential mechanism.Methods:ALDOA was knocked down by short hairpin RNA in H520 and H1299 cells.ALDOA was overexpressed with vectors carrying the full-length ALDOA sequence in H1299 and H157 cells.The proliferation capacities were assessed with immunohistochemical staining,Cell Counting Kit-8 and colony formation assays.The cell cycle distribution was examined by flow cytometry,and molecular alterations were determined by western blotting.Cell synchronization was induced with nocodazole.The stability of cyclin D1 mRNA was tested.The pyruvate kinase M2 and ALDOA protein distributions were examined.Aerobic glycolysis was evaluated with Cell Titer-Glo assay,glucose colorimetric assay and lactate colorimetric assay.Results:ALDOA knockdown inhibited the proliferation and G1/S transition in H520 cells.Conversely,ALDOA over-expression promoted the proliferation and G1/S transition in H157 cells.The cell cycle synchronization assay showed that ALDOA expression increased in the G1 phase and G1/S transition.Furthermore,ALDOA knockdown reduced cyclin D1 expression by regulating epidermal growth factor receptor/mitogen-activated protein kinase(EGFR/MAPK)pathway.Similar results were found in H1299 and H157 cells.The inhibition of mitogen-activated protein kinase kinase 1/2 prompted the nuclear distribution of ALDOA.Additionally,ALDOA knockdown reduced nuclear distribution of PKM2,the extracellular lactate and intracellular adenosine triphosphate concentrations and elevated the extracellular glucose concentration.Conclusions:ALDOA contributed to activation of the EGFR/MAPK pathway,thus promoting cyclin D1 expression and enhancing proliferation and G1/S transition in NSCLC.Additionally,ALDOA facilitated NSCLC aerobic glycolysis.