Rabbit Anti-Human FGF20. (a.a. 25-211) Polyclonal antibody

Fibroblast growth factor 20 (FGF20) is a member of the FGF family with potential for use in several different therapeutic categories. In this work, we provide the first structural characterization of FGF20 using a wide variety of approaches. Like other members of the FGF family, FGF20 appears to possess a beta-trefoil structure. The effect of pH on the conformation and thermal stability of FGF20 is evaluated using far-UV circular dichroism (CD), intrinsic and ANS fluorescence, and high-resolution derivative UV absorption spectroscopy. Empirical phase diagrams are constructed to describe the solution behavior of FGF20 over a wide pH and temperature range. The protein appears to be unstable at pH < 5, with aggregation and precipitation observed during dialysis. A major heat-induced conformational change also causes aggregation and precipitation of FGF20 at elevated temperatures. The highest thermal stability is observed near neutral pH (T-m similar to 55 degrees C at pH 7). The effect of several high- and low-molecular mass polyanions on the thermal stability of FGF20 is also examined using CD, intrinsic fluorescence, and DSC analysis. Among these ligands, heparin exhibits the greatest stabilizing effect on FGF20, increasing the T-m by more than 10 degrees C.

Osteoporosis and sarcopenia (osteosarcopenia (OS)) are twin-aging diseases. The biochemical crosstalk between muscle and bone seems to play a role in OS. We have previously shown that osteocytes produce soluble factors with beneficial effects on muscle and vice versa. Recently, enhanced FGF9 production was observed in the OmGFP66 osteogenic cell line. To test its role in myogenic differentiation, C2C12 myoblasts were treated with recombinant FGF9. FGF9 as low as 10 ng/mL inhibited myogenic differentiation, suggesting that FGF9 might be a potential inhibitory factor produced from bone cells with effects on muscle cells. FGF9 (10-50 ng/mL) significantly decreased mRNA expression of MyoG and Mhc while increasing the expression of Myostatin. Consistent with the phenotype, RT-qPCR array revealed that FGF9 (10 ng/mL) increased the expression of Icam1 while decreased the expression of Wnt1 and Wnt6 decreased, respectively. FGF9 decreased caffeine-induced Ca2+ release from the sarcoplasmic reticulum (SR) of C2C12 myotubes and reduced the expression of genes (i.e. Cacna1s, RyR2, Naftc3) directly associated with intracellular Ca2+ homeostasis. Myogenic differentiation in human skeletal muscle cells was similarly inhibited by FGF9 but required higher doses of 200 ng/mL FGF9. FGF9 was also shown to stimulate C2C12 myoblast proliferation. FGF2 and the FGF9 subfamily members FGF16 and FGF20 also inhibited C2C12 myoblast differentiation and enhanced proliferation. Intriguingly, the differentiation inhibition was independent of proliferation enhancement. These findings suggest that FGF9 may modulate myogenesis via a complex signaling mechanism.