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.

Autophagy in the pathogenesis and therapeutic potential of post-traumatic osteoarthritis

Autophagy,as a fundamental mechanism for cellular homeostasis,is generally involved in the occurrence and progression of various diseases.Osteoarthritis(OA)is the most common muscu-loskeletal disease that often leads to pain,disability and economic loss in patients.Post-traumatic OA(PTOA)is a subtype of OA,accounting for>12%of the overall burden of OA.PTOA is often caused by joint injuries including anterior cruciate ligament rupture,meniscus tear and intra-articular fracture.Although a variety of methods have been developed to treat acute joint injury,the current measures have limited success in effectively reducing the incidence and delaying the progression of PTOA.Therefore,the pathogenesis and intervention strategy of PTOA need further study.In the past decade,the roles and mechanisms of autophagy in PTOA have aroused great interest in the field.It was revealed that autophagy could maintain the homeostasis of chondrocytes,reduce joint inflammatory level,prevent chondrocyte death and matrix degradation,which accordingly improved joint symptoms and delayed the progression of PTOA.Moreover,many strategies that target PTOA have been revealed to promote autophagy.In this review,we summarize the roles and mechanisms of autophagy in PTOA and the current strategies for PTOA treatment that depend on autophagy regulation,which may be beneficial for PTOA patients in the future.

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.