ABSTRACT
STUDY DESIGN: Experimental human study. PURPOSE: To determine whether angiopoietin-like protein 2 (ANGPTL2) is highly expressed in the hyperplastic facet joint (FJ) synovium and whether it activates interleukin-6 (IL-6) secretion in FJ synoviocytes. OVERVIEW OF LITERATURE: Mechanical stress-induced synovitis is partially, but significantly, responsible for degenerative and subsequently osteoarthritic changes in the FJ tissues in patients with lumbar spinal stenosis (LSS). However, the underlying molecular mechanism remains unclear. IL-6 is highly expressed in degenerative FJ synovial tissue and is responsible for local chronic inflammation. ANGPTL2, an inflammatory and mechanically induced mediator, promotes the expression of IL-6 in many cells. METHODS: FJ tissues were harvested from five patients who had undergone lumbar surgery. Immunohistochemistry for ANGPTL2, IL-6, and cell markers was performed in the FJ tissue samples. After cultured synoviocytes from the FJ tissues were subjected to mechanical stress, ANGPTL2 expression and secretion were measured quantitatively using real-time quantitative reverse-transcription–polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA), respectively. Following ANGPTL2 administration in the FJ synoviocytes, anti-nuclear factor-κB (NF-κB) activation was investigated using immunocytochemistry, and IL-6 expression and secretion were assayed quantitatively with or without NF-κB inhibitor. Moreover, we assessed whether ANGPTL2-induced IL-6 modulates leucocyte recruitment in the degenerative process by focusing on the monocyte chemoattractant protein-1 (MCP-1) expression. RESULTS: ANGPTL2 and IL-6 were highly expressed in the hyperplastic FJ synovium samples. ANGPTL2 was co-expressed in both, fibroblast-like and macrophage-like synoviocytes. Further, the expression and secretion of ANGPTL2 in the FJ synoviocytes increased in response to stimulation by mechanical stretching. ANGPTL2 protein promoted the nuclear translocation of NF-κB and induced IL-6 expression and secretion in the FJ synoviocytes. This effect was reversed following treatment with NF-κB inhibitor. Furthermore, ANGPTL2-induced IL-6 upregulated the MCP-1 expression in the FJ synoviocytes. CONCLUSIONS: Mechanical stress-induced ANGPTL2 promotes chronic inflammation in the FJ synovium by activating IL-6 secretion, leading to FJ degeneration and subsequent LSS.
Subject(s)
Humans , Chemokine CCL2 , Enzyme-Linked Immunosorbent Assay , Immunohistochemistry , Inflammation , Interleukin-6 , Spinal Stenosis , Stress, Mechanical , Synovial Membrane , Synovitis , Zygapophyseal JointABSTRACT
Background: Laparoscopic gastrectomy has several difficult points including,lymph node dissection and resection of several blood vessels for trainee surgeons.Recently, preoperative evaluation of vasculature based three-dimensional (3D)imaging technique resulted in a significantly improved clinical outcome inabdominal surgery. The aim of this study is to investigate the usefulness of the 3Dimage in laparoscopic gastrectomy for trainee surgeons.Method: We adopted a multiphase CT protocol to acquire 3 image sets (arterial,portal, and equilibrium phases). 3D-reconstruction of gastric vasculature wasmade using data from a contrast enhanced MDCT and SYNAPSE VINCENTsoftware. Whole pancreas, spleen, gastric vasculature were extracted from MDCTscans and traced. Thirty three patients, who underwent laparoscopic gastrectomyfor gastric cancer during the period between Jan 2013 and May 2014 wereexamined in this study. Four trainees performed a 19 laparoscopic gastrectomy,while 14 laparoscopic gastrectomy were conducted by the two trainers. Thesurgical outcomes in both groups and the pattern of gastric vasculatures wereevaluated.Result: 3D imaging technique showed a correct positional relationship betweenthe stomach, gastric vessels, pancreas and spleen. Surgical outcome includingestimated blood loss, and operative time in trainee group were not significantlydifferent compared to trainer group. 3D imaging technique showed a correctpositional relationship between the stomach, gastric vessels, pancreas and spleen.Regarding vascular pattern detected by 3D imaging, the origins of IPA were RGEAin 12 cases (36%), GDA in 8 cases (24%).bifurcation of RGEA and GDA in7 cases(21%), and not detected in 1 case (3%), respectively. The types of confluence ofIPV were RGEV in 16 cases (48%), ASPDV in 10 cases (30%), and not detectedin 7 cases (21%), respectively.Conclusions: 3D imaging technique might contribute to successful laparoscopicgastrectomy. Preoperative 3D-simulation techniques enabled trainee surgeons toeasily and safely perform laparoscopic gastrectomy.
ABSTRACT
Background: Laparoscopic gastrectomy has several difficult points including, lymph node dissection and resection of several blood vessels for trainee surgeons. Recently, preoperative evaluation of vasculature based three-dimensional (3D) imaging technique resulted in a significantly improved clinical outcome in abdominal surgery. The aim of this study is to investigate the usefulness of the 3D image in laparoscopic gastrectomy for trainee surgeons. Method: We adopted a multiphase CT protocol to acquire 3 image sets (arterial, portal, and equilibrium phases). 3D-reconstruction of gastric vasculature was made using data from a contrast enhanced MDCT and SYNAPSE VINCENT software. Whole pancreas, spleen, gastric vasculature were extracted from MDCT scans and traced. Thirty three patients, who underwent laparoscopic gastrectomy for gastric cancer during the period between Jan 2013 and May 2014 were examined in this study. Four trainees performed a 19 laparoscopic gastrectomy, while 14 laparoscopic gastrectomy were conducted by the two trainers. The surgical outcomes in both groups and the pattern of gastric vasculatures were evaluated. Result: 3D imaging technique showed a correct positional relationship between the stomach, gastric vessels, pancreas and spleen. Surgical outcome including estimated blood loss, and operative time in trainee group were not significantly different compared to trainer group. 3D imaging technique showed a correct positional relationship between the stomach, gastric vessels, pancreas and spleen. Regarding vascular pattern detected by 3D imaging, the origins of IPA were RGEA in 12 cases (36%), GDA in 8 cases (24%).bifurcation of RGEA and GDA in7 cases (21%), and not detected in 1 case (3%), respectively. The types of confluence of IPV were RGEV in 16 cases (48%), ASPDV in 10 cases (30%), and not detected in 7 cases (21%), respectively. Conclusions: 3D imaging technique might contribute to successful laparoscopic gastrectomy. Preoperative 3D-simulation techniques enabled trainee surgeons to easily and safely perform laparoscopic gastrectomy.