Panoply™ Human DLL4 Knockdown Stable Cell Line

To improve the efficacy of autologous fat grafting (AFG) in reconstructive surgery, researchers have demonstrated the novel use of adipose-derived mesenchymal stem cells (ADSCs) and their extracellular vesicles (EVs) as delivery vehicles for delta-like ligand 4 (DLL4) siRNA. This study aimed to inhibit the DLL4 gene. Transcriptome analysis identified DLL4 as a key regulatory gene in endothelial cells of AFG tissue, negatively impacting endothelial cell function and graft survival through the Notch signaling pathway. By engineering ADSC EVs to carry DLL4 siRNA (ADSC EVs-siDLL4), the study demonstrated significant improvements in endothelial cell proliferation, migration, and tube formation, enhanced in vivo angiogenesis, and ultimately significantly improved AFG survival. This approach represents a significant advancement in tissue engineering and regenerative medicine, offering a potential approach to overcome the limitations of current fat grafting techniques.

To investigate the relationship between DLL4 expression and angiogenesis, the researchers isolated and characterized mVECs (Figure 1A). Furthermore, they established DLL4-overexpressing and control cell lines (oe-DLL4 and oe-NC) (Figure 1B and C). The angiogenic capacity of these cell lines was assessed using proliferation, migration, and tube formation assays. Results showed that compared with oe-NC, oe-DLL4 had significantly reduced proliferation, migration, and tube formation abilities. Next, they investigated whether DLL4 inhibition could enhance the angiogenic capacity of mVECs. Researchers generated DLL4 knockdown cell lines (sh-DLL4 and sh-NC) using mVECs as a basis (Figure 1D and E) and blocked DLL4 using anti-DLL4 antibody or its isotype control. Changes in various cell markers were then assessed. Results showed that, compared with sh-NC or isotype controls, proliferation, migration, and tube formation abilities were significantly upregulated in the DLL4 knockdown cell lines or in the anti-DLL4 antibody-treated groups (Figure 1F-I), indicating that DLL4 inhibition can promote the angiogenic capacity of mVECs.

Figure 1. Overexpression and knockdown of delta-like ligand 4 (DLL4) in microvascular endothelial cells (mVECs) and the effect of DLL4 knockdown on vascular formation ability in mVECs. (Deng S L, et al., 2024)