RSPO3/SDC-1 Pathway Dysfunction in Alveolar Repair After ARDS in Older Adults

"Peripheral Blood: 5 mL collected into EDTA tubes; PBMCs isolated within 2 h for RT-qPCR analysis of RSPO3/SDC-1 mRNA and sandwich ELISA quantification of protein levels.~Saliva: 2-3 mL unstimulated saliva naturally expectorated into sterile tubes, kept at 4 °C and processed within 2 h (centrifuged, aliquoted) before -80 °C storage Subcutaneous Fat: 100-200 mg obtained during elective procedures, preserved in RNAlater at 4 °C for 24 h, then frozen at -80 °C 3D Alveolar Organoid Assay: Lung tissue-derived organoids are cultured in Matrigel and treated ex vivo with recombinant RSPO3 or SDC-1 neutralizing antibody; epithelial repair is assessed over 7 days by Ki-67 immunostaining and wound-closure measurement"

"Peripheral Blood: 5 mL collected into EDTA tubes; PBMCs isolated within 2 h for RT-qPCR analysis of RSPO3/SDC-1 mRNA and sandwich ELISA quantification of protein levels.~Saliva: 2-3 mL unstimulated saliva naturally expectorated into sterile tubes, kept at 4 °C and processed within 2 h (centrifuged, aliquoted) before -80 °C storage"