Aims: 

Pituitary adenylate cyclase-activating polypeptide PACAP, is widely distributed in the human body. It can be found in the central nervous system but it was detected in endocrine glands and gonads as well. We do not have any evidence of its function in skeletal elements such as hyaline cartilage.

Methods: 

We investigated the effects of PACAP addition and its function in oxidative stress on in vitro formation of cartilage in high density micromass cell cultures of chicken embryonic chondrogenic cells.

Results: 

The mRNA expression of PACAP, PAC1 receptor and protein expression of PAC1 receptor were detected in chondrogenic cells. Administration of PACAP 1-38 and 6-38 increased cartilage formation. It compensated the degeneration effect of 4 mM H₂O₂. Viability of chondrifying cells was constant as a result of PACAP proteins or H₂O₂, while both PACAPs increased the proliferation rate with preventing the antiproliferative effect of oxidative stress. The presence of PACAP proteins increased the mRNA and protein expression of ERK1/2 and elevated the presence of dual phosphorylated ERK1/2. We also demonstrated that addition of PACAP proteins increased the mRNA and protein expression of Ca²⁺-calmodulin dependent Ser/Thr protein phosphatase so called calcineurin. Moreover, it played important role in compensation of the reduction of calineurin activity during oxidative stress.

Conclusion: 

In chondrifying experimental model, we demonstrated the presence of PACAP and its receptor. The administration of PACAP 1-38 elevated cartilage production as well as the PACAP 6-38. Our results also give evidence that calcineurin take important part in the regulation of PACAP signaling pathways.