Probiotic Sonicates Selectively Induce Mucosal Immune Cells Apoptosis Through Ceramide Generation Via Neutral Sphingolyelinase

Background: Probiotics appear to be beneficial in inflammatory bowel disease, but their mechanism of action is incompletely understood. We investigated whether probiotic-derived sphingomyelinase mediates this beneficial effect. Methodology/Principal Findings: Neutral sphingomyelinase (NSMase) activity was measured in sonicates of the probiotic L.brevis (LB)and S. thermophilus (ST) and the non-probiotic E. coli EC) and E. faecalis (EF). Lamina propria mononuclear cells (LPMC) were obtained from patients with Crohn"s disease (CD) and Ulcerative Colitis (UC), and peripheral blood mononuclear cells (PBMC) from healthy volunteers, analysing LPMC and PBMC apoptosis susceptibility, reactive oxygen species (ROS) generation and JNK activation. In some experiments, sonicates were preincubated with GSH or GW4869, a specific NSMase inhibitor. NSMase activity of LB and ST was 10-fold that of EC and EF sonicates. LB and ST sonicates induced significantly more apoptosis of CD and UC than control LPMC, whereas EC and EF sonicates failed to induce apoptosis. Pre-stimulation with anti-CD3/CD28 induced a significant and time-dependent increase in LB-induced apoptosis of LPMC and PBMC. Exposure to LB sonicates resulted in JNK activation and ROS production by LPMC. NSMase activity of LB sonicates was completely abrogated by GW4869, causing a dose-dependent reduction of LB -induced poptosis. LB and ST selectively induced immune cell apoptosis, an effect dependent on the degree of cell activation and mediated by bacterial NSMase. Conclusions: These results suggest that induction of immune cell apoptosis is a mechanism of action of some probiotics and that NSMase-mediated ceramide generation contributes to the therapeutic effects of probiotics

Prostaglandin E2 Exerts Multiple Regulatory Actions on Human Obese Adipose Tissue Remodeling, Inflammation, Adaptive Thermogenesis and Lipolysis

Obesity induces white adipose tissue (WAT) dysfunction characterized by unremitting inflammation and fibrosis, impaired adaptive thermogenesis and increased lipolysis. Prostaglandins (PGs) are powerful lipid mediators that influence the homeostasis of several organs and tissues. The aim of the current study was to explore the regulatory actions of PGs in human omental WAT collected from obese patients undergoing laparoscopic bariatric surgery. In addition to adipocyte hypertrophy, obese WAT showed remarkable inflammation and total and pericellular fibrosis. In this tissue, a unique molecular signature characterized by altered expression of genes involved in inflammation, fibrosis and WAT browning was identified by microarray analysis. Targeted LC-MS/MS lipidomic analysis identified increased PGE2 levels in obese fat in the context of a remarkable COX-2 induction and in the absence of changes in the expression of terminal prostaglandin E synthases (i.e. mPGES-1, mPGES-2 and cPGES). IPA analysis established PGE2 as a common top regulator of the fibrogenic/inflammatory process present in this tissue. Exogenous addition of PGE2 significantly reduced the expression of fibrogenic genes in human WAT explants and significantly down-regulated Col1α1, Col1α2 and αSMA in differentiated 3T3 adipocytes exposed to TGF-β. In addition, PGE2 inhibited the expression of inflammatory genes (i.e. IL-6 and MCP-1) in WAT explants as well as in adipocytes challenged with LPS. PGE2 anti-inflammatory actions were confirmed by microarray analysis of human pre-adipocytes incubated with this prostanoid. Moreover, PGE2 induced expression of brown markers (UCP1 and PRDM16) in WAT and adipocytes, but not in pre-adipocytes, suggesting that PGE2 might induce the trans-differentiation of adipocytes towards beige/brite cells. Finally, PGE2 inhibited isoproterenol-induced adipocyte lipolysis. Taken together, these findings identify PGE2 as a regulator of the complex network of interactions driving uncontrolled inflammation and fibrosis and impaired adaptive thermogenesis and lipolysis in human obese visceral WAT

Adjuvant therapy sparing in rectal cancer achieving complete response after chemoradiation

AIM: To evaluate the long-term results of conventional chemoradiotherapy and laparoscopic mesorectal excision in rectal adenocarcinoma patients without adjuvant therapy. METHODS: Patients with biopsy-proven adenocarcinoma of the rectum staged cT3-T4 by endoscopic ultrasound or magnetic resonance imaging received neoadjuvant continuous infusion of 5-fluorouracil for five weeks and concomitant radiotherapy. Laparoscopic surgery was planned after 5-8 wk. Patients diagnosed with ypT0N0 stage cancer were not treated with adjuvant therapy according to the protocol. Patients with ypT1-2N0 or ypT3-4 or N+ were offered 5-fluorouracil-based adjuvant treatment on an individual basis. An external cohort was used as a reference for the findings. RESULTS: One hundred and seventy six patients were treated with induction chemoradiotherapy and 170 underwent total mesorectal excision. Cancer staging of ypT0N0 was achieved in 26/170 (15.3%) patients. After a median follow-up of 58.3 mo, patients with ypT0N0 had five-year disease-free and overall survival rates of 96% (95%CI: 77-99) and 100%, respectively. We provide evidence about the natural history of patients with localized rectal cancer achieving a complete response after preoperative chemoradiation. The inherent good prognosis of these patients will have implications for clinical trial design and care of patients. CONCLUSION: Withholding adjuvant chemotherapy after complete response following standard neoadjuvant chemoradiotherapy and laparoscopic mesorectal excision might be safe within an experienced multidisciplinary team

Probiotic Sonicates Selectively Induce Mucosal Immune Cells Apoptosis Through Ceramide Generation Via Neutral Sphingolyelinase

Background: Probiotics appear to be beneficial in inflammatory bowel disease, but their mechanism of action is incompletely understood. We investigated whether probiotic-derived sphingomyelinase mediates this beneficial effect. Methodology/Principal Findings: Neutral sphingomyelinase (NSMase) activity was measured in sonicates of the probiotic L.brevis (LB)and S. thermophilus (ST) and the non-probiotic E. coli EC) and E. faecalis (EF). Lamina propria mononuclear cells (LPMC) were obtained from patients with Crohn"s disease (CD) and Ulcerative Colitis (UC), and peripheral blood mononuclear cells (PBMC) from healthy volunteers, analysing LPMC and PBMC apoptosis susceptibility, reactive oxygen species (ROS) generation and JNK activation. In some experiments, sonicates were preincubated with GSH or GW4869, a specific NSMase inhibitor. NSMase activity of LB and ST was 10-fold that of EC and EF sonicates. LB and ST sonicates induced significantly more apoptosis of CD and UC than control LPMC, whereas EC and EF sonicates failed to induce apoptosis. Pre-stimulation with anti-CD3/CD28 induced a significant and time-dependent increase in LB-induced apoptosis of LPMC and PBMC. Exposure to LB sonicates resulted in JNK activation and ROS production by LPMC. NSMase activity of LB sonicates was completely abrogated by GW4869, causing a dose-dependent reduction of LB -induced poptosis. LB and ST selectively induced immune cell apoptosis, an effect dependent on the degree of cell activation and mediated by bacterial NSMase. Conclusions: These results suggest that induction of immune cell apoptosis is a mechanism of action of some probiotics and that NSMase-mediated ceramide generation contributes to the therapeutic effects of probiotics

Adjuvant therapy sparing in rectal cancer achieving complete response after chemoradiation

AIM: To evaluate the long-term results of conventional chemoradiotherapy and laparoscopic mesorectal excision in rectal adenocarcinoma patients without adjuvant therapy. METHODS: Patients with biopsy-proven adenocarcinoma of the rectum staged cT3-T4 by endoscopic ultrasound or magnetic resonance imaging received neoadjuvant continuous infusion of 5-fluorouracil for five weeks and concomitant radiotherapy. Laparoscopic surgery was planned after 5-8 wk. Patients diagnosed with ypT0N0 stage cancer were not treated with adjuvant therapy according to the protocol. Patients with ypT1-2N0 or ypT3-4 or N+ were offered 5-fluorouracil-based adjuvant treatment on an individual basis. An external cohort was used as a reference for the findings. RESULTS: One hundred and seventy six patients were treated with induction chemoradiotherapy and 170 underwent total mesorectal excision. Cancer staging of ypT0N0 was achieved in 26/170 (15.3%) patients. After a median follow-up of 58.3 mo, patients with ypT0N0 had five-year disease-free and overall survival rates of 96% (95%CI: 77-99) and 100%, respectively. We provide evidence about the natural history of patients with localized rectal cancer achieving a complete response after preoperative chemoradiation. The inherent good prognosis of these patients will have implications for clinical trial design and care of patients. CONCLUSION: Withholding adjuvant chemotherapy after complete response following standard neoadjuvant chemoradiotherapy and laparoscopic mesorectal excision might be safe within an experienced multidisciplinary team

Adjuvant therapy sparing in rectal cancer achieving complete response after chemoradiation

AIM: To evaluate the long-term results of conventional chemoradiotherapy and laparoscopic mesorectal excision in rectal adenocarcinoma patients without adjuvant therapy. METHODS: Patients with biopsy-proven adenocarcinoma of the rectum staged cT3-T4 by endoscopic ultrasound or magnetic resonance imaging received neoadjuvant continuous infusion of 5-fluorouracil for five weeks and concomitant radiotherapy. Laparoscopic surgery was planned after 5-8 wk. Patients diagnosed with ypT0N0 stage cancer were not treated with adjuvant therapy according to the protocol. Patients with ypT1-2N0 or ypT3-4 or N+ were offered 5-fluorouracil-based adjuvant treatment on an individual basis. An external cohort was used as a reference for the findings. RESULTS: One hundred and seventy six patients were treated with induction chemoradiotherapy and 170 underwent total mesorectal excision. Cancer staging of ypT0N0 was achieved in 26/170 (15.3%) patients. After a median follow-up of 58.3 mo, patients with ypT0N0 had five-year disease-free and overall survival rates of 96% (95%CI: 77-99) and 100%, respectively. We provide evidence about the natural history of patients with localized rectal cancer achieving a complete response after preoperative chemoradiation. The inherent good prognosis of these patients will have implications for clinical trial design and care of patients. CONCLUSION: Withholding adjuvant chemotherapy after complete response following standard neoadjuvant chemoradiotherapy and laparoscopic mesorectal excision might be safe within an experienced multidisciplinary team

Protective ileostomy creation after anterior resection of the rectum: Shared decision-making or still subjective?

Aim: The choice of whether to perform protective ileostomy (PI) after anterior resection (AR) is mainly guided by risk factors (RFs) responsible for the development of anastomotic leakage (AL). However, clear guidelines about PI creation are still lacking in the literature and this is often decided according to the surgeon's preferences, experiences or feelings. This qualitative study aims to investigate, by an open-ended question survey, the individual surgeon's decision-making process regarding PI creation after elective AR. Method: Fifty four colorectal surgeons took part in an electronic survey to answer the questions and describe what usually led their decision to perform PI. A content analysis was used to code the answers. To classify answers, five dichotomous categories (In favour/Against PI, Listed/Unlisted RFs, Typical/Atypical, Emotions/Non-emotions, Personal experience/No personal experience) have been developed. Results: Overall, 76% of surgeons were in favour of PI creation and 88% considered listed RFs in the question of whether to perform PI. Atypical answers were reported in 10% of cases. Emotions and personal experience influenced surgeons' decision-making process in 22% and 49% of cases, respectively. The most frequently considered RFs were the distance of the anastomosis from the anal verge (96%), neoadjuvant chemoradiotherapy (88%), a positive intraoperative leak test (65%), blood loss (37%) and immunosuppression therapy (35%). Conclusion: The indications to perform PI following rectal cancer surgery lack standardization and evidence-based guidelines are required to inform practice. Until then, expert opinion can be helpful to assist the decision-making process in patients who have undergone AR for adenocarcinoma