ABSTRACT
Objective To investigate the effect of human platelet-rich plasma-derived exosomes(PRP-exos)on the proliferation of Schwann cell(SC)cultured in vitro. Methods PRP-exos were extracted by polymerization-precipitation combined with ultracentrifugation.The morphology of PRP-exos was observed by transmission electron microscopy,and the concentration and particle size distribution of PRP-exos were determined by nanoparticle tracking analysis.Western blotting was employed to determine the expression of the marker proteins CD63,CD81,and CD9 on exosome surface and the platelet membrane glycoprotein CD41.The SCs of rats were isolated and cultured,and the expression of the SC marker S100β was detected by immunofluorescence staining.The fluorescently labeled PRP-exos were co-cultured with SCs in vitro for observation of their interaction.EdU assay was employed to detect the effect of PRP-exos on SC proliferation,and CCK-8 assay to detect the effects of PRP-exos at different concentrations(0,10,20,40,80,and 160 μg/ml)on SC proliferation. Results The extracted PRP-exos appeared as uniform saucer-shaped vesicles with the average particle size of(122.8±38.7)nm and the concentration of 3.5×1012 particles/ml.CD63,CD81,CD9,and CD41 were highly expressed on PRP-exos surface(P<0.001,P=0.025,P=0.004,and P=0.032).The isolated SCs expressed S100β,and PRP-exos could be taken up by SCs.PRP-exos of 40,80,and 160 μg/ml promoted the proliferation of SCs,and that of 40 μg/ml showed the best performance(all P<0.01). Conclusions High concentrations of PRP-exos can be extracted from PRP.PRP-exos can be taken up by SCs and promote the proliferation of SCs cultured in vitro.
Subject(s)
Humans , Rats , Animals , Exosomes/metabolism , Platelet-Rich Plasma , Schwann Cells , Coculture Techniques , Cell Proliferation , Cells, CulturedABSTRACT
This paper is to illustrate the infestation and related ecological characteristics of chigger mites on the Asian house rat (Rattus tanezumi). A total of 17,221 chigger mites were collected from 2,761 R. tanezumi rats, and then identified as 131 species and 19 genera in 2 families. Leptotrombidium deliense, the most powerful vector of scrub typhus in China, was the first major dominant species on R. tanezumi. All the dominant mite species were of an aggregated distribution among different individuals of R. tanezumi. The species composition and infestations of chiggers on R. tanezumi varied along different geographical regions, habitats and altitudes. The species-abundance distribution of the chigger mite community was successfully fitted and the theoretical curve equation was Ŝ (R)=37e–(0.28R)2. The total chigger species on R. tanezumi were estimated to be 199 species or 234 species, and this further suggested that R. tanezumi has a great potential to harbor abundant species of chigger mites. The results of the species-plot relationship indicated that the chigger mite community on R. tanezumi in Yunnan was an uneven community with very high heterogeneity. Wide geographical regions with large host samples are recommended in the investigations of chigger mites.
ABSTRACT
This paper is to illustrate the infestation and related ecological characteristics of chigger mites on the Asian house rat (Rattus tanezumi). A total of 17,221 chigger mites were collected from 2,761 R. tanezumi rats, and then identified as 131 species and 19 genera in 2 families. Leptotrombidium deliense, the most powerful vector of scrub typhus in China, was the first major dominant species on R. tanezumi. All the dominant mite species were of an aggregated distribution among different individuals of R. tanezumi. The species composition and infestations of chiggers on R. tanezumi varied along different geographical regions, habitats and altitudes. The species-abundance distribution of the chigger mite community was successfully fitted and the theoretical curve equation was Ŝ (R)=37e–(0.28R)2. The total chigger species on R. tanezumi were estimated to be 199 species or 234 species, and this further suggested that R. tanezumi has a great potential to harbor abundant species of chigger mites. The results of the species-plot relationship indicated that the chigger mite community on R. tanezumi in Yunnan was an uneven community with very high heterogeneity. Wide geographical regions with large host samples are recommended in the investigations of chigger mites.
ABSTRACT
OBJECTIVE@#To analyze the role of endoplasmic reticulum stress response in the development of osteoblast apoptosis and osteolysis in osteolytic bone tissue, and to explore the causes of artificial joint loosening, so as to provide new ideas and theoretical basis for the prevention and treatment of artificial joint loosening.@*METHODS@#The animal model of osteolysis induced by wear particles was established by mouse skull, and randomly divided into 4 groups, 7 rats in each group:group 1, blank control group;group 2, wear particles tial6v4 nano alloy powder (TiNPs) group;group 3, endoplasmic reticulum stress response positive control (TiNPs+Tg) group; group 4, endoplasmic reticulum stress response inhibitor (TiNPs+4-PBA) group. The pathological changes of osteolysis were observed by toluidine blue staining, HE staining and ALP staining;the expression of endoplasmic reticulum stress response marker protein was detected by Western Blotting;the apoptosis of osteoblasts in osteolytic skull tissue was detected by TUNEL and Caspase-3 immunohistochemistry.@*RESULTS@#Wear particles TiNPs can induce osteolysis in vitro, aggravate the infiltration of inflammatory cells and inhibit the differentiation and maturation of osteoblasts. At the same time, wear particles can also up regulate the markers of endoplasmic reticulum stress response and promote the apoptosis of osteoblasts in osteolytic bone tissue. After adding 4-PBA, an inhibitor of endoplasmic reticulum stress (4-PBA), on the basis of wear particles TiNPs, the symptoms of osteolysis were significantly relieved, bone erosion and inflammatory infiltration were significantly reduced, the differentiation and maturation of osteoblasts were improved, the number of apoptotic osteoblasts decreased sharply, and the expression of endoplasmic reticulum stress marker protein gradually decreased.@*CONCLUSION@#Endoplasmic reticulum stress is involved in the formation of osteolysis and plays an important role in the occurrence and development of osteolysis. At the same time, endoplasmic reticulum stress can be used as a new therapeutic target to provide new ideas and methods for clinical reversal or treatment of osteolysis and aseptic loosening.