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Aim To explore the effect of endoplasmic reticulum (ER) stress-related exosomes derived from hepatocellular carcinoma (HCC) cells on the M2 polarization of macrophages via Toll-like receptor 4 (TLR4) and the underlying mechanism. Methods Western blot experiments were conducted to evaluate the GRP78 levels in HCC tissues and HCC cells with or without pre-treatment of tunicamycin and the identification of the isolated exosomes. Immunohistochemical staining was also employed to detect the expression of GRP78 in HCC tissues. Immunofluorescence was used to confirm the effective absorbance of exosomes by macrophages. Flow cytometry ( FCM ) , Western blot and CBA kit were used to detect M2 polarization-asso ciated markers and the expression of TLR4 on macrophages. Affymetrix gene chip and bioinformatics analy-sis were used to screen the differential expression of mRNA in macrophages stimulated by ER stressed-relat- ed exosomes and TLR4 expression. Results In clinical samples, GRP78 expression in liver cancer tissues was higher than that in the adjacent tissues. In cell experiments, tunicamycin (2.5 jxmol • L"1 ) treatment for 24 hours in HCC cells could significantly increase the expression of ER stress marker protein GRP78 compared with control group. Western blot showed that HCC cell-derived exosomes positively expressed exosom- al marker proteins,such as CD63,TSG101 and HSP70, and negatively expressed Calnexin. Interestingly, HSP70-enriched exosomes released by ER-stressed HCC cells were observed. Laser confocal microscopy found that exosomes could be effectively taken up by RAW264.7 macrophages. Flow cytometry and Western blot further indicated that ER stress-related exosomes could significantly up-regulate the expression of CD206, transformed growth factor-beta (TGF-p) and arginase-1 (Arg-1) in macrophages. Meanwhile, these exosomes could promote the secretion of IL-6 and IL- 10,and up-regulate the expression of TLR4 in macrophages. Conclusions ER stressed-HCC cells could promote macrophage M2 polarization by releasing HSP70-enriched exosomes and activating TLR4 signaling.
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<p><b>Background</b>Jejunal feeding tube allows the nutrition of critical care patients more easy and safe. However, its placement remains a challenge. This study aimed to introduce a jejunal feeding tube through an ultrasound-guided antral progressive water injection method and subsequently to examine its efficacy.</p><p><b>Methods</b>Between April 2016 and April 2017, 54 patients hospitalized in the Department of Critical Care Medicine, Peking Union Medical College Hospital, China who needed nutritional support through a jejunal feeding tube were recruited for this study. Patients who applied ultrasound-guided antral progressive water injection method were classified into the experimental group. Patients who applied conventional method were registered as control group.</p><p><b>Results</b>No significant differences were found in age, body mass index, and Acute Physiology and Chronic Health Evaluation score, but a significant difference in operation time was found between the experimental group and the control group. Of the 24 individuals in the control group, 17 displayed clear catheter sound shadows once the tube entered the esophagus. In comparison, of the 30 individuals in the experimental group, all harbored catheter sound shadows through the esophageal gas injection method. Subsequent observation revealed that in the control group (via ultrasonographic observation), 15 individuals underwent successful antral tube entry, for a success rate of 63%. In the experimental group (via antral progressive water injection), 27 individuals underwent successful antral tube entry, for a success rate of 90%. There was a significant difference between the success rates of the two groups (χ = 5.834, P = 0.022).</p><p><b>Conclusion</b>The antral progressive water injection method for the placement of a jejunal feeding tube is more effective than the traditional ultrasonic placement method.</p>