Fig. 1.

Decreased endogenous FGF1 levels in diabetic individuals and comparably protective function of FGF1^WT and FGF1^ΔHBS in high-glucose-treated cardiomyocytes. a Serum levels of FGF1 in healthy subjects (n = 17), T2D patients with (n = 10) and without (n = 12) DCM. b Correlation between serum FGF1 levels and fractional shortening (FS) in T2D patients. c Correlation between serum FGF1 and BNP levels in T2D patients. d Serum FGF1 levels in db/m (Ctrl) and db/db (T2D) mice determined by ELISA. n = 6. e Representative western blot analysis of FGF1 in cardiac tissues from db/m and db/db mice. GAPDH was a loading control. f Densitometric quantification of western blots as shown in e. n = 6. g–l Contractile properties of primary cardiomyocytes from adult C57Bl/6J mice were treated with FGF1^WT or FGF1^ΔHBS (500 ng/mL for 1 h) and exposed to high glucose (HG, 35 mM) for 5 h. n = 62–65. g Resting cell length. h Peak shortening normalized to resting cell length. i Maximal velocity of shortening (+dL/dt). j Maximal velocity of re-lengthening (−dL/dt). k Time to peak shortening. l Time to 90% re-lengthening. Data were mean ± SEM; *P < 0.05, **P < 0.01, ***P < 0.001