Annual Variation of Water Quality in Aquaculture Ponds for Apostichopus japonicus

By measuring water temperature,salinity,pH,dissolved oxygen,nitrite and ammonia nitrogen,the annual variation regularity of water quality in the aquaculture ponds for sea cucumbers Apostichopus japonicus in Dalian were studied.Results showed that the physicochemical indicators kept changing in the year,and the various ranges of water temperature,salinity,pH,dissolved oxygen,nitrite,and ammonia nitrogen were 6.38-27.27℃,29.20‰-33.78‰,7.86-8.38,5.19-13.36 mg/L,0.0037-0.0090 mg/L and 0.0171-0.0908 mg/L,respectively.Analysis indicated that there was an extremely significant negative correlation between water temperature and dissolved oxygen(P<0.01),an extremely significant positive correlation between water temperature and ammonia nitrogen(P<0.01),a significant negative correlation between salinity and nitrite(P<0.05),a significant negative correlation between dissolved oxygen and nitrite(P<0.05),and an extremely significant negative correlation between dissolved oxygen and ammonia nitrogen(P<0.01)in the aquaculture ponds for sea cucumber in Dalian.Research showed that the water quality of aquaculture ponds kept fluctuating all the time during the tested period,there were complicated and close relationships among physicochemical indicators,and a slight variation of external factors would bring consecutive reactions to different indicators in the water quality of aquaculture ponds.A reference for the production and management of sea cucumbers could be provided from the results.

Tropoelastin improves adhesion and migration of intra-articular injected infrapatellar fat pad MSCs and reduces osteoarthritis progression

Intra-articular injection of mesenchymal stem cells(MSCs)is a promising strategy for osteoarthritis(OA)treatment.However,more and more studies reveal that the injected MSCs have poor adhesion,migration,and survival in the joint cavity.A recent study shows that tropoelastin(TE)regulates adhesion,proliferation and phenotypic maintenance of MSCs as a soluble additive,indicating that TE could promote MSCs-homing in regenerative medicine.In this study,we used TE as injection medium,and compared it with classic media in MSCs intra-articular injection such as normal saline(NS),hyaluronic acid(HA),and platelet-rich plasma(PRP).We found that TE could effectively improve adhesion,migration,chondrogenic differentiation of infrapatellar fat pad MSCs(IPFP-MSCs)and enhance matrix synthesis of osteoarthritic chondrocytes(OACs)in indirect-coculture system.Moreover,TE could significantly enhance IPFP-MSCs adhesion via activation of integrin β1,ERK1/2 and vinculin(VCL)in vitro.In addition,intra-articular injection of TE-IPFP MSCs suspension resulted in a short-term increase in survival rate of IPFP-MSCs and better histology scores of rat joint tissues.Inhibition of integrin β1 or ERK1/2 attenuated the protective effect of TE-IPFP MSCs suspension in vivo.In conclusion,TE promotes performance of IPFP-MSCs and protects knee cartilage from damage in OA through enhancement of cell adhesion and activation of integrin β1/ERK/VCL pathway.Our findings may provide new insights in MSCs intra-articular injection for OA treatment.