OBJECTIVETo explore effects and potential mechanisms of high insulin environment on high density lipoprotein (HDL) generation-related functional protein ABCA1.

METHODS[(3)H] labeled cholesterol efflux from mature 3T3-L1 adipocytes was detected by liquid scintillation counting. ABCA1 mRNA and protein expression in mature 3T3-L1 adipocytes post stimulation with various concentrations of insulin was detected by real-time fluorescence-based quantitative techniques and Western blot, respectively, in the absence and presence of CHX (cycloheximide, CHX), calpeptin (calpain pathway inhibitor) or MG-132 (proteasome pathway inhibitor).

RESULTSCholesterol efflux rates were reduced post insulin stimulation in a dose-dependent manner ((7.06 ± 0.27)%, (6.59 ± 0.30)%, (6.34 ± 0.24)%, (5.07 ± 0.40)%, and (4.71 ± 0.40)% at 0, 1, 10, 10², and 10³ nmol/L of insulin, P < 0.05). Cholesterol efflux rates decreased in a time-dependent manner post 10³ nmol/L insulin stimulation (6.52 ± 0.30)%, (5.59 ± 0.71)%, (5.44 ± 0.37)%, (4.52 ± 0.32)%, and (4.38 ± 0.33)% at 0, 2, 4, 6, 12 h, respectively). ABCA1mRNA levels were not affected by insulin (P > 0.05). ABCA1 protein level was significantly downregulated in 10³ nmol/L insulin group compared to 0 nmol/L insulin group (P < 0.01). Compared with the 0 h group, ABCA1 protein level was significantly reduced in 6 h group (P < 0.05) and further reduced in 12 h group (P < 0.01). Both calpeptin and MG-132 could partly reduce insulin-induced degradation of ABCA1. Compared with the negative control group, ABCA1 protein levels were significantly upregulated by cotreatment with calpeptin and MG-132, respectively (both P < 0.01).

CONCLUSIONOur data suggest that high insulin level could promote the ABCA1 protein degradation and reduce cholesterol efflux from mature 3T3-L1 adipocytes through calpain and proteasome pathway, thus, produce a circumference not suitable for nascent HDL formation in 3T3-L1 adipocytes.

3T3-L1 Cells ; ATP Binding Cassette Transporter 1 ; Adipocytes ; Animals ; Calpain ; Insulin ; Leupeptins ; Lipoproteins, HDL ; Mice ; Proteasome Endopeptidase Complex ; RNA, Messenger

Objective: To evaluate the feasibility and safety of applying enhanced recovery after surgery (ERAS) protocol in patients undergoing laparoscopic distal pancreatectomy. Methods: Data of 36 patients undergoing laparoscopic distal pancreatectomy from May 2016 to May 2017 in the First Affiliated Hospital, Zhejiang University School of Medicine were reviewed. The patients were divided into ERAS group (n=12) and control group (n=24). The patients in ERAS group received a series of enhanced recovery procedures, including multimodal analgesia, early off-bed activity and early oral food-taking, etc. Operation time, intraoperative blood loss, time to first flatus, postoperative complications, and length of postoperative hospital stay were evaluated. Results: There were no statistically significant differences in operation time and intraoperative blood loss between ERAS group and control group (all P0.05). The time to first flatus and length of postoperative hospital stay were significantly shortened in ERAS group (all P<0.05). The ERAS group had lower incidence of postoperative complications (41.7% vs. 66.7%), and the complications in ERAS group tended to be milder, but the differences failed to show statistical significance (all P0.05). Conclusion: The ERAS protocol for laparoscopic distal pancreatectomy can significantly promote gastrointestinal function recovery and shorten postoperative hospital stay, and may reduce the incidence of postoperative complications.
Case-Control Studies ; Humans ; Laparoscopy ; standards ; Length of Stay ; Pancreatectomy ; instrumentation ; methods ; Postoperative Complications ; prevention & control ; Postoperative Period ; Retrospective Studies