Fig. 1: lnc668 promoted fibroblast-to-myofibroblast differentiation in TGF-β1-activated MRC-5 cells.

a qRT-PCR confirmed that the expression of lnc668 gradually increased in the TGF-β1 group compared with that in the control group and peaked at 72 h. b RNA FISH images revealed that lnc668 was present in the nucleus and cytoplasm but was predominantly present in the nucleus. After TGF-β1 stimulation, lnc668 was upregulated in the nucleus and cytoplasm, with a more pronounced increase in the cytoplasm than in the nucleus. After si-lnc668 treatment, lnc668 levels were downregulated in the nucleus and cytoplasm, whereas lnc668 overexpression resulted in upregulation in both compartments, with a more significant increase in the nucleus than in the cytoplasm. c The nuclear-cytoplasmic separation experiments confirmed that lnc668 was primarily expressed in the nucleus of MRC-5 cells, with TGF-β1 stimulation increasing its cytoplasmic levels. Overexpression of lnc668 similarly elevated its cytoplasmic expression, while lnc668 interference disrupted its nuclear-cytoplasmic shuttling. d Immunofluorescence images revealed that cells treated with TGF-β1 exhibited a spindle shape and an increased expression of the α-SMA protein compared with the normal cell group. Comparison with the TGF-β1 group revealed that α-SMA expression was inhibited by lnc668 silencing and promoted by lnc668 overexpression. Blue represents nuclei marked with DAPI. Green indicates the presence of α-SMA in the cytoplasm. e Western blot analysis revealed that lnc668 intervention downregulated the expression levels of FAP, α-SMA, VIM, COL1A, and COL3A, whereas lnc668 overexpression led to increased levels of these proteins. f IncuCyteS3 analysis revealed that cell proliferation decreased in the si-lnc668 group and increased in the lnc668 overexpression group. g Scratch assay results showed that cell migration in the si-lnc668 group decreased and that in the lnc668 overexpressing group increased compared with that in the control group.