Fig. (2) MSC-CM confers protection against cytokine-driven apoptosis in islet cell models. BRIN-BD11 and βTC1.6 cells were exposed to 1 µg/ml IFN-γ, 100 ng/ml TNF-α, and 100 ng/ml IL-1β for 24h in the presence or absence of MSC-CM and the induction of apoptosis assessed by TUNEL assay. (A) Fluorescent images showing the ability of MSC-CM to reduce the % of positive TUNEL cells after cytokine challenge. 1% H₂O₂ acted as a positive control in these experiments. Blue staining represents DAPI staining of the nuclei while green staining indicates TUNEL positive cells (B) The % of positive TUNEL cells was measured by calculating the number of TUNEL positive cells divided by the total number of cells. Data are presented as mean ± standard deviation (SD) with n=3. ***P<0.001 compared with untreated controls. The scale bar in all images equals 100 µm. MSC-CM, Mesenchymal Stem Cell Condition Media; IFN-γ, Interferon gamma; TNF-α, tumour necrosis factor alpha; IL-1β, Interleukin 1 beta.