# Application of Conditioned Medium for In Vitro Modeling and Repair of Respiratory Tissue
## 3 Results
### Application of CM from Non-Respiratory Cells or Tissues  
Non-respiratory tissues were also included to elucidate the role of the secretome in in vitro modeling to discover secretome applications in respiratory in vitro models. Adipose-derived stem cells [51], THP-1 monocytes [52; 53], 3T3 cells [54], MSC [36; 55; 56; 57; 58; 59; 60; 61], and macrophages [62] were among the cells used. Particle-exposed cells such as Buenos Aires urban air particles (UAP-BA)- and residual oil fly ash (ROFA)-treated cells [63] were also included, along with bacteria secretome such as that of _Staphylococcus aureus_[64]. A total of 16 articles were evaluated, which involved >20 separate tests. The most common tests, which were performed in seven studies, were viability and migration assays [36; 51; 52; 54; 55; 56; 62]. Aside from specific marker expression assays, such as immunofluorescence assays, PCR, ELISA, and Western blotting that were evaluated in 15 of the 16 publications, some studies performed uncommon tests, such as ERK1/2 phosphorylation [57], a PPAR activity assay [62], Hoechst 33258 staining assay [58], and luciferase assay [53], all of which were conducted in a single study. Table 2 summarizes the results of various studies evaluating conditioned media (CM) from different cell types and bacteria, which demonstrated \begin{table}
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**CELL TYPE** & **CM CHARACTER-ISTICS** & **EXPERIMENTAL EVALUATION** & **RESULTS AND CONCLUSIONS** \\ \hline \multirow{9}{*}{Lung carcinoma EC (A549) [50]} & From THP-1 cells co-cultured with A549, treated with Metropolitan and untreated co-culture (UT-CM) & & - A549 activated pro-inflammatory response of THP-1 cells by \(\uparrow\) TNF-\(\alpha\) and IL-6 production. - Tectoringin inhibited TNF-\(\alpha\) and IL-6 released by THP-1 cells. - T-CM inhibited cell migration rate and cell invasion compared to UT-CM. - T-CM \(\downarrow\) EMT, observed by \(\downarrow\) E-cadherin and Snail expression. - Tectoringin can prevent lung cancer by inducing an inflammatory and pro-metastatic response in monocytes. & - Bel-7402 co-cultured with HL-7702 or RF/6A \(\downarrow\) migration and invasion of Bel-7402, \(\uparrow\) epithelial marker (E-cadherin-catenin complex) expression, EMT-promoting transcription factors and mesenchymal markers. - MRC-5-CM \(\uparrow\) invasion and migration rate, inhibited tumorigenicity and viability and \(\uparrow\) laminin and integrin expression on Beel-7402. - The findings emphasized the powerful effects of TM on tumor growth via EMI and MEF by influencing the expression of adhesion molecules such as laminins and integrins. & - 3 DCM \(\uparrow\) cell attachment compared to 2 DCM but not significantly. - 2 DCM \(\uparrow\) cell proliferation compared to 3 DCM and control; however, the difference in all groups was not significant. - 2 DCM and 3 DCM \(\uparrow\) cytoprotective effect. - Protein concentration was higher in 3 DCM compared to 2 DCM. - Conclusion: Cytoprotective effect by 3 DCM on proliferating nasal fibroblast cells was equivalent to that of 2 DCM. \\ \hline \hline \end{tabular} Abbreviations: \(\uparrow\) = increase; \(\downarrow\) = decrease; FGF7 = fibroblast growth factor 7; COPD = chronic obstructive pulmonary disease; EMT = epithelial–mesenchymal transition; MET = mesenchymal–epithelial transition; IL-6 = interleukin 6; IL-8 = interleukin 8; MMP2 = matrix metalloproteinases 2; SPARC = osteonectin; CCR5 = C-C motif chemokine receptor 5; TNF-\(\alpha\) = tumor necrosis factor \(\alpha\); VEGF = vascular endothelial growth factor; HA2 KY\({}_{7}\) = phosphorylated H2A histone family member \(\chi\); H2O\({}_{2}\) = hydrogen peroxide.  
\end{table} 
Table 1: _Cont._their ability to promote regeneration, exert protective effects, inhibit fibrosis, and induce epithelial breakdown. Notably, the CM from MSC showed the most promising results in promoting proliferation, wound closure, and exerting antifibrotic effects.