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A47 THE GUT MICROBIOTA INFLUENCES COLONIC HEALING AFTER SURGERY IN PATIENTS UNDERGOING BOWEL RESECTION FOR COLORECTAL CANCER. J Can Assoc Gastroenterol 2023. [PMCID: PMC9991308 DOI: 10.1093/jcag/gwac036.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
Background The standard treatment of colorectal cancer (CRC) consists of a surgical resection of the colonic segment with the tumor, followed by a reconnection of the remaining bowel ends, or "anastomosis". The anastomosis may fail to heal in up to 20% of patients, which leads to anastomotic leak, a major complication that increases postoperative morbidity and mortality. This complication is unpredictable and its causes remain poorly understood. Purpose The objective of this study is to investigate the possible role of the gut microbiome in anastomotic healing after surgery in patients with CRC. Method We collected preoperative fecal samples and intraoperative mucosal samples from CRC patients undergoing surgery with anastomosis. The gut microbiota of patients with AL and of others that presented optimal healing after surgery was analyzed and compared using the Anchor 16S pipeline. To assess the role of the patients' microbiota in healing, fecal microbiota transplantation (FMT) was performed in mice using preoperative fecal samples from CRC patients with and without AL. Mice were then subjected to colonic surgery using a colonic anastomosis model. Six days after surgery, anastomotic healing was assessed macroscopically and microscopically. The gut barrier function was also assessed. The gut microbiota composition was compared between the groups colonized with samples from patients with and without AL to detect potential differences. Result(s) Mice colonized by FMT with the microbiota of donors with AL displayed poor anastomotic healing macroscopically, and a weaker wound microscopically. These same mice displayed a weaker gut barrier, as objectified by higher bacterial translocation to the spleen. The anastomoses of mice receiving the microbiota of AL donors displayed lower concentrations of collagen and fibronectin and higher inflammatory cytokines and collagenolytic enzymes, indicating poor extracellular matrix formation and collagen degradation locally.The beta-diversity of the gut microbiota was significantly different between mice receiving the microbiota of donors with and without AL, and several bacterial species were differentially abundant between the two groups. Conclusion(s) The preoperative gut microbiota in CRC patients who experience anastomotic leak after surgery induces poor anastomotic healing in mice and a weaker gut barrier after colonic surgery. Several bacterial species were found to be associated with the healing process. Please acknowledge all funding agencies by checking the applicable boxes below CIHR, Other Please indicate your source of funding; NSERC, FRQS, New Frontiers in Research, Montreal Cancer Institute. Disclosure of Interest None Declared
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2021 Canadian Surgery Forum01. Design and validation of a unique endoscopy simulator using a commercial video game03. Is ethnicity an appropriate measure of health care marginalization?: A systematic review and meta-analysis of the outcomes of diabetic foot ulceration in the Aboriginal population04. Racial disparities in surgery — a cross-specialty matched comparison between black and white patients05. Starting late does not increase the risk of postoperative complications in patients undergoing common general surgical procedures06. Ethical decision-making during a health care crisis: a resource allocation framework and tool07. Ensuring stability in surgical training program leadership: a survey of program directors08. Introducing oncoplastic breast surgery in a community hospital09. Leadership development programs for surgical residents: a review of the literature10. Superiority of non-opioid postoperative pain management after thyroid and parathyroid operations: a systematic review and meta-analysis11. Timing of ERCP relative to cholecystectomy in patients with ductal gallstone disease12. A systematic review and meta-analysis of randomized controlled trials comparing intraoperative red blood cell transfusion strategies13. Postoperative outcomes after frail elderly preoperative assessment clinic: a single-institution Canadian perspective14. Selective opioid antagonists following bowel resection for prevention of postoperative ileus: a systematic review and meta-analysis15. Peer-to-peer coaching after bile duct injury16. Laparoscopic median arcuate ligament release: a video abstract17. Retroperitoneoscopic approach to adrenalectomy19. Endoscopic Zenker diverticulotomy: a video abstract20. Variability in surgeons’ perioperative management of pheochromocytomas in Canada21. The contribution of surgeon and hospital variation in transfusion practice to outcomes for patients undergoing elective gastrointestinal cancer surgery: a population-based analysis22. Perioperative transfusions for gastroesophageal cancers: risk factors and short- and long-term outcomes23. The association between frailty and time alive and at home after cancer surgery among older adults: a population-based analysis24. Psychological and workplace-related effects of providing surgical care during the COVID-19 pandemic in British Columbia, Canada25. Safety of venous thromboembolism prophylaxis in endoscopic retrograde cholangiopancreatography: a systematic review26. Complications and reintervention following laparoscopic subtotal cholecystectomy: a systematic review and meta-analysis27. Synchronization of pupil dilations correlates with team performance in a simulated laparoscopic team coordination task28. Receptivity to and desired design features of a surgical peer coaching program: an international survey9. Impact of the COVID-19 pandemic on rates of emergency department utilization due to general surgery conditions30. The impact of the current COVID-19 pandemic on the exposure of general surgery trainees to operative procedures31. Association between academic degrees and research productivity: an assessment of academic general surgeons in Canada32. Laparoscopic endoscopic cooperative surgery (LECS) for subepithelial gastric lesion: a video presentation33. Effect of the COVID-19 pandemic on acute care general surgery at an academic Canadian centre34. Opioid-free analgesia after outpatient general surgery: a pilot randomized controlled trial35. Impact of neoadjuvant immunotherapy or targeted therapies on surgical resection in patients with solid tumours: a systematic review and meta-analysis37. Surgical data recording in the operating room: a systematic review of modalities and metrics38. Association between nonaccidental trauma and neighbourhood socioeconomic status during the COVID-19 pandemic: a retrospective analysis39. Laparoscopic repair of a transdiaphragmatic gastropleural fistula40. Video-based interviewing in medicine: a scoping review41. Indocyanine green fluorescence angiography for prevention of anastomotic leakage in colorectal surgery: a cost analysis from the hospital payer’s perspective43. Perception or reality: surgical resident and faculty assessments of resident workload compared with objective data45. When illness and loss hit close to home: Do health care providers learn how to cope?46. Remote video-based suturing education with smartphones (REVISE): a randomized controlled trial47. The evolving use of robotic surgery: a population-based analysis48. Prophylactic retromuscular mesh placement for parastomal hernia prevention: a retrospective cohort study of permanent colostomies and ileostomies49. Intracorporeal versus extracorporeal anastomosis in laparoscopic right hemicolectomy: a retrospective cohort study on anastomotic complications50. A lay of the land — a description of Canadian academic acute care surgery models51. Emergency general surgery in Ontario: interhospital variability in structures, processes and models of care52. Trauma 101: a virtual case-based trauma conference as an adjunct to medical education53. Assessment of the National Surgical Quality Improvement Program Surgical Risk Calculator for predicting patient-centred outcomes of emergency general surgery patients in a Canadian health care system54. Sustainability of a narcotic reduction initiative: 1 year following the Standardization of Outpatient Procedure (STOP) Narcotics Study55. Barriers to transanal endoscopic microsurgery referral56. Geospatial analysis of severely injured rural patients in a geographically complex landscape57. Implementation of an incentive spirometry protocol in a trauma ward: a single-centre pilot study58. Impostor phenomenon is a significant risk factor for burnout and anxiety in Canadian resident physicians: a cross-sectional survey59. Understanding the influence of perioperative education on performance among surgical trainees: a single-centre experience60. The effect of COVID-19 pandemic on current and future endoscopic personal protective equipment practices: a national survey of 77 endoscopists61. Case report: delayed presentation of perforated sigmoid diverticulitis as necrotizing infection of the lower limb62. Investigating disparities in surgical outcomes in Canadian Indigenous populations63. Fundoplication is superior to medical therapy for Barrett esophagus disease regression and progression: a systematic review and meta-analysis64. Development of a novel online general surgery learning platform and a qualitative preimplementation analysis65. Hagfish slime exudate as a potential novel hemostatic agent: developing a standardized assessment protocol66. The effect of the first wave of the COVID-19 pandemic on surgical oncology case volumes and wait times67. Safety of same-day discharge in high-risk patients undergoing ambulatory general surgery68. External validation of the Codman score in colorectal surgery: a pragmatic tool to drive quality improvement69. Improved morbidity and gastrointestinal restoration rates without compromising survival rates for diverting loop ileostomy with colonic lavage versus total abdominal colectomy for fulminant Clostridioides difficile colitis: a multicentre retrospective cohort study70. Potential access to emergency general surgical care in Ontario71. Immersive virtual reality (iVR) improves procedural duration, task completion and accuracy in surgical trainees: a systematic review01. Clinical validation of the Canada Lymph Node Score for endobronchial ultrasound02. Venous thromboembolism in surgically treated esophageal cancer patients: a provincial population-based study03. Venous thromboembolism in surgically treated lung cancer patients: a population-based study04. Is frailty associated with failure to rescue after esophagectomy? A multi-institutional comparative analysis of outcomes05. Routine systematic sampling versus targeted sampling of lymph nodes during endobronchial ultrasound: a feasibility randomized controlled trial06. Gastric ischemic conditioning reduces anastomotic complications in patients undergoing esophagectomy: a systematic review and meta-analysis07. Move For Surgery, a novel preconditioning program to optimize health before thoracic surgery: a randomized controlled trial08. In case of emergency, go to your nearest emergency department — Or maybe not?09. Does preoperative SABR increase the risk of complications from lung cancer resection? A secondary analysis of the MISSILE trial10. Segmental resection for lung cancer: the added value of near-infrared fluorescence mapping diminishes with surgeon experience11. Toward competency-based continuing professional development for practising surgeons12. Stereotactic body radiotherapy versus surgery in older adults with NSCLC — a population-based, matched analysis of long-term dependency outcomes13. Role of adjuvant therapy in esophageal cancer patients after neoadjuvant therapy and curative esophagectomy: a systematic review and meta-analysis14. Evaluation of population characteristics on the incidence of thoracic empyema: an ecological study15. Determining the optimal stiffness colour threshold and stiffness area ratio cut-off for mediastinal lymph node staging using EBUS elastography and AI: a pilot study16. Quality assurance on the use of sequential compression stockings in thoracic surgery (QUESTs)17. The relationship between fissureless technique and prolonged air leak for patients undergoing video-assisted thoracoscopic lobectomy18. CXCR2 inhibition as a candidate for immunomodulation in the treatment of K-RAS-driven lung adenocarcinoma19. Assessment tools for evaluating competency in video-assisted thoracoscopic lobectomy: a systematic review20. Understanding the current practice on chest tube management following lung resection among thoracic surgeons across Canada21. Effect of routine jejunostomy tube insertion in esophagectomy: a systematic review and meta-analysis22. Recurrence of primary spontaneous pneumothorax following bullectomy with pleurodesis or pleurectomy: a retrospective analysis23. Surgical outcomes following chest wall resection and reconstruction24. Outcomes following surgical management of primary mediastinal nonseminomatous germ cell tumours25. Does robotic approach offer better nodal staging than thoracoscopic approach in anatomical resection for non–small cell lung cancer? A single-centre propensity matching analysis26. Competency assessment for mediastinal mass resection and thymectomy: design and Delphi process27. The contemporary significance of venous thromboembolism (deep venous thrombosis [DVT] and pulmonary embolus [PE]) in patients undergoing esophagectomy: a prospective, multicentre cohort study to evaluate the incidence and clinical outcomes of VTE after major esophageal resections28. Esophageal cancer: symptom severity at the end of life29. The impact of pulmonary artery reconstruction on postoperative and oncologic outcomes: a systematic review30. Association with surgical technique and recurrence after laparoscopic repair of paraesophageal hernia: a single-centre experience31. Enhanced recovery after surgery (ERAS) in esophagectomy32. Surgical treatment of esophageal cancer: trends in surgical approach and early mortality at a single institution over the past 18 years34. Adverse events and length of stay following minimally invasive surgery in paraesophageal hernia repair35. Long-term symptom control comparison of Dor and Nissen fundoplication following laparoscopic para-esophageal hernia repair: a retrospective analysis36. Willingness to pay: a survey of Canadian patients’ willingness to contribute to the cost of robotic thoracic surgery37. Radiomics in early-stage lung adenocarcinoma: a prediction tool for tumour immune microenvironments38. Effectiveness of intraoperative pyloric botox injection during esophagectomy: how often is endoscopic intervention required?39. An artificial intelligence algorithm for predicting lymph node malignancy during endobronchial ultrasound40. The effect of major and minor complications after lung surgery on length of stay and readmission41. Measuring cost of adverse events following thoracic surgery: a scoping review42. Laparoscopic paraesophageal hernia repair: characterization by hospital and surgeon volume and impact on outcomes43. NSQIP 5-Factor Modified Frailty Index predicts morbidity but not mortality after esophagectomy44. Trajectory of perioperative HRQOL and association with postoperative complications in thoracic surgery patients45. Variation in treatment patterns and outcomes for resected esophageal cancer at designated thoracic surgery centres46. Patient-reported pretreatment health-related quality of life (HRQOL) predicts short-term survival in esophageal cancer patients47. Analgesic efficacy of surgeon-placed paravertebral catheters compared with thoracic epidural analgesia after Ivor Lewis esophagectomy: a retrospective noninferiority study48. Rapid return to normal oxygenation after lung surgery49. Examination of local and systemic inflammatory changes during lung surgery01. Implications of near-infrared imaging and indocyanine green on anastomotic leaks following colorectal surgery: a systematic review and meta-analysis02. Repeat preoperative endoscopy after regional implementation of electronic synoptic endoscopy reporting: a retrospective comparative study03. Consensus-derived quality indicators for operative reporting in transanal endoscopic surgery (TES)04. Colorectal lesion localization practices at endoscopy to facilitate surgical and endoscopic planning: recommendations from a national consensus Delphi process05. Black race is associated with increased mortality in colon cancer — a population-based and propensity-score matched analysis06. Improved survival in a cohort of patients 75 years and over with FIT-detected colorectal neoplasms07. Laparoscopic versus open loop ileostomy reversal: a systematic review and meta-analysis08. Posterior mesorectal thickness as a predictor of increased operative time in rectal cancer surgery: a retrospective cohort study09. Improvement of colonic anastomotic healing in mice with oral supplementation of oligosaccharides10. How can we better identify patients with rectal bleeding who are at high risk of colorectal cancer?11. Assessment of long-term bowel dysfunction in rectal cancer survivors: a population-based cohort study12. Observational versus antibiotic therapy for acute uncomplicated diverticulitis: a noninferiority meta-analysis based on a Delphi consensus13. Radiotherapy alone versus chemoradiotherapy for stage I anal squamous cell carcinoma: a systematic review and meta-analysis14. Is the Hartmann procedure for diverticulitis obsolete? National trends in colectomy for diverticulitis in the emergency setting from 1993 to 201515. Sugammadex in colorectal surgery: a systematic review and meta-analysis16. Sexuality and rectal cancer treatment: a qualitative study exploring patients’ information needs and expectations on sexual dysfunction after rectal cancer treatment17. Video-based interviews in selection process18. Impact of delaying colonoscopies during the COVID-19 pandemic on colorectal cancer detection and prevention19. Opioid use disorder associated with increased anastomotic leak and major complications after colorectal surgery20. Effectiveness of a rectal cancer education video on patient expectations21. Robotic-assisted rectosigmoid and rectal cancer resection: implementation and early experience at a Canadian tertiary centre22. An online educational app for rectal cancer survivors with low anterior resection syndrome: a pilot study23. The effects of surgeon specialization on the outcome of emergency colorectal surgery24. Outcomes after colorectal cancer resections in octogenarians and older in a regional New Zealand setting — What are the predictors of mortality?25. Long-term outcomes after seton placement for perianal fistulae with and without Crohn disease26. A survey of patient and surgeon preference for early ileostomy closure following restorative proctectomy for rectal cancer — Why aren’t we doing it?27. Crohn disease independently associated with longer hospital admission after surgery28. Short-stay (≤ 1 d) diverting loop ileostomy closure can be selectively implemented without an increase in readmission and complication rates: an ACS-NSQIP analysis29. A comparison of perineal stapled rectal prolapse resection and the Altemeier procedure at 2 Canadian academic hospitals30. Mental health and substance use disorders predict 90-day readmission and postoperative complications following rectal cancer surgery31. Early discharge after colorectal cancer resection: trends and impact on patient outcomes32. Oral antibiotics without mechanical bowel preparation prior to emergency colectomy reduces the risk of organ space surgical site infections: a NSQIP propensity score matched study33. The impact of robotic surgery on a tertiary care colorectal surgery program, an assessment of costs and short-term outcomes — a Canadian perspective34. Should we scope beyond the age limit of guidelines? Adenoma detection rates and outcomes of screening and surveillance colonoscopies in patients aged 75–79 years35. Emergency department admissions for uncomplicated diverticulitis: a nationwide study36. Obesity is associated with a complicated episode of acute diverticulitis: a nationwide study37. Green indocyanine angiography for low anterior resection in patients with rectal cancer: a prospective before-and-after study38. The impact of age on surgical recurrence of fibrostenotic ileocolic Crohn disease39. A qualitative study to explore the optimal timing and approach for the LARS discussion01. Racial, ethnic and socioeconomic disparities in diagnosis, treatment and survival of patients with breast cancer: a SEER-based population analysis02. First-line palliative chemotherapy for esophageal and gastric cancer: practice patterns and outcomes in the general population03. Frailty as a predictor for postoperative outcomes following pancreaticoduodenectomy04. Synoptic electronic operative reports identify practice variation in cancer surgery allowing for directed interventions to decrease variation05. The role of Hedgehog signalling in basal-like breast cancer07. Clinical and patient-reported outcomes in oncoplastic breast conservation surgery from a single surgeon’s practice in a busy community hospital in Canada08. Upgrade rate of atypical ductal hyperplasia: 10 years of experience and predictive factors09. Time to first adjuvant treatment after oncoplastic breast reduction10. Preparing to survive: improving outcomes for young women with breast cancer11. Opioid prescription and consumption in patients undergoing outpatient breast surgery — baseline data for a quality improvement initiative12. Rectal anastomosis and hyperthermic intraperitoneal chemotherapy: Should we avoid diverting loop ileostomy?13. Delays in operative management of early-stage, estrogen-receptor positive breast cancer during the COVID-19 pandemic — a multi-institutional matched historical cohort study14. Opioid prescribing practices in breast oncologic surgery15. Oncoplastic breast reduction (OBR) complications and patient-reported outcomes16. De-escalating breast cancer surgery: Should we apply quality indicators from other jurisdictions in Canada?17. The breast cancer patient experience of telemedicine during COVID-1918. A novel ex vivo human peritoneal model to investigate mechanisms of peritoneal metastasis in gastric adenocarcinoma (GCa)19. Preliminary uptake and outcomes utilizing the BREAST-Q patient-reported outcomes questionnaire in patients following breast cancer surgery20. Routine elastin staining improves detection of venous invasion and enhances prognostication in resected colorectal cancer21. Analysis of exhaled volatile organic compounds: a new frontier in colon cancer screening and surveillance22. A clinical pathway for radical cystectomy leads to a shorter hospital stay and decreases 30-day postoperative complications: a NSQIP analysis23. Fertility preservation in young breast cancer patients: a population-based study24. Investigating factors associated with postmastectomy unplanned emergency department visits: a population-based analysis25. Impact of patient, tumour and treatment factors on psychosocial outcomes after treatment in women with invasive breast cancer26. The relationship between breast and axillary pathologic complete response in women receiving neoadjuvant chemotherapy for breast cancer01. The association between bacterobilia and the risk of postoperative complications following pancreaticoduodenectomy02. Surgical outcome and quality of life following exercise-based prehabilitation for hepatobiliary surgery: a systematic review and meta-analysis03. Does intraoperative frozen section and revision of margins lead to improved survival in patients undergoing resection of perihilar cholangiocarcinoma? A systematic review and meta-analysis04. Prolonged kidney procurement time is associated with worse graft survival after transplantation05. Venous thromboembolism following hepatectomy for colorectal metastases: a population-based retrospective cohort study06. Association between resection approach and transfusion exposure in liver resection for gastrointestinal cancer07. The association between surgeon volume and use of laparoscopic liver resection for gastrointestinal cancer08. Immune suppression through TIGIT in colorectal cancer liver metastases09. “The whole is greater than the sum of its parts” — a combined strategy to reduce postoperative pancreatic fistula after pancreaticoduodenectomy10. Laparoscopic versus open synchronous colorectal and hepatic resection for metastatic colorectal cancer11. Identifying prognostic factors for overall survival in patients with recurrent disease following liver resection for colorectal cancer metastasis12. Modified Blumgart pancreatojejunostomy with external stenting in laparoscopic Whipple reconstruction13. Laparoscopic versus open pancreaticoduodenectomy: a single centre’s initial experience with introduction of a novel surgical approach14. Neoadjuvant chemotherapy versus upfront surgery for borderline resectable pancreatic cancer: a single-centre cohort analysis15. Thermal ablation and telemedicine to reduce resource utilization during the COVID-19 pandemic16. Cost-utility analysis of normothermic machine perfusion compared with static cold storage in liver transplantation in the Canadian setting17. Impact of adjuvant therapy on overall survival in early-stage ampullary cancers: a single-centre retrospective review18. Presence of biliary anaerobes enhances response to neoadjuvant chemotherapy in pancreatic ductal adenocarcinoma19. How does tumour viability influence the predictive capability of the Metroticket model? Comparing predicted-to-observed 5-year survival after liver transplant for hepatocellular carcinoma20. Does caudate resection improve outcomes in patients undergoing curative resection for perihilar cholangiocarcinoma? A systematic review and meta-analysis21. Appraisal of multivariable prognostic models for postoperative liver decompensation following partial hepatectomy: a systematic review22. Predictors of postoperative liver decompensation events following resection in patients with cirrhosis and hepatocellular carcinoma: a population-based study23. Characteristics of bacteriobilia and impact on outcomes after Whipple procedure01. Inverting the y-axis: the future of MIS abdominal wall reconstruction is upside down02. Progressive preoperative pneumoperitoneum: a single-centre retrospective study03. The role of radiologic classification of parastomal hernia as a predictor of the need for surgical hernia repair: a retrospective cohort study04. Comparison of 2 fascial defect closure methods for laparoscopic incisional hernia repair01. Hypoalbuminemia predicts serious complications following elective bariatric surgery02. Laparoscopic adjustable gastric band migration inducing jejunal obstruction associated with acute pancreatitis: aurgical approach of band removal03. Can visceral adipose tissue gene expression determine metabolic outcomes after bariatric surgery?04. Improvement of kidney function in patients with chronic kidney disease and severe obesity after bariatric surgery: a systematic review and meta-analysis05. A prediction model for delayed discharge following gastric bypass surgery06. Experiences and outcomes of Indigenous patients undergoing bariatric surgery: a mixed-methods scoping review07. What is the optimal common channel length in revisional bariatric surgery?08. Laparoscopic management of internal hernia in a 34-week pregnant woman09. Characterizing timing of postoperative complications following elective Roux-en-Y gastric bypass and sleeve gastrectomy10. Canadian trends in bariatric surgery11. Common surgical stapler problems and how to correct them12. Management of choledocholithiasis following Roux-en-Y gastric bypass: a systematic review and meta-analysis. Can J Surg 2021; 64:S80-S159. [PMID: 35483046 PMCID: PMC8677574 DOI: 10.1503/cjs.021321] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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A229 PROMOTION OF COLONIC ANASTOMOTIC HEALING WITH PERIOPERATIVE SUPPLEMENTATION WITH OLIGOSACCHARIDES. J Can Assoc Gastroenterol 2021. [DOI: 10.1093/jcag/gwab002.227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Colorectal resection is a standard procedure in the management of colorectal cancer (CRC) and inflammatory bowel disease. Anastomotic leak (AL) is a major complication in colorectal resections, and the gut microbiota may play a role in the healing and development of AL. Short-chain fatty acids (SCFAs), namely butyrate, have been involved in anastomotic healing when administered into the bowel via enema. Due to the mechanical stress associated with enemas after the confection of a fresh and fragile anastomosis, other butyrate-increasing strategies are required.
Aims
To promote anastomotic healing and prevent AL by using inulin and galacto-oligosaccharides (GOS) supplementation to modulate the microbiota toward a butyrate-producing profile.
Methods
Mice were fed diets supplemented with inulin, GOS or cellulose, as a non-fermentable control, for two weeks and underwent a proximal colonic anastomosis under general anesthesia. Healing of the anastomosis, both macroscopically and microscopically, was assessed six days after surgery. Epithelial proliferation, mucus production and integrity of the gut barrier were assessed.
Results
Inulin and GOS supplementation increased SCFAs in the colon and were associated with better postoperative weight recovery and macroscopic anastomotic healing. Microscopically, mucosal continuity was promoted by inulin and GOS. Mucus production was found to be similar in all groups. The gut barrier was found to be improved with inulin and GOS as shown by less bacterial translocation.
Conclusions
Inulin and GOS may prevent AL and promote anastomotic healing. This effect appears to be mediated by improved mucosal proliferation.
Funding Agencies
CIHRNatural Sciences and Engineering Research Council of Canada; Institut du cancer de Montréal; Fonds de recherche du Québec en santé
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Clinical Correlates of Human Immunodeficiency Virus-1 (HIV-1) DNA and Inducible HIV-1 RNA Reservoirs in Peripheral Blood in Children With Perinatally Acquired HIV-1 Infection With Sustained Virologic Suppression for at Least 5 Years. Clin Infect Dis 2021; 70:859-866. [PMID: 30919879 DOI: 10.1093/cid/ciz251] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 03/20/2019] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND The Early Pediatric Initiation Canada Child Cure Cohort (EPIC4) study is a prospective, multicenter, Canadian cohort study investigating human immunodeficiency virus-1 (HIV-1) reservoirs, chronic inflammation, and immune responses in children with perinatally acquired HIV-1 infection. The focus of this report is HIV-1 reservoirs and correlates in the peripheral blood of children who achieved sustained virologic suppression (SVS) for ≥5 years. METHODS HIV-1 reservoirs were determined by measuring HIV-1 DNA in peripheral blood mononuclear cells and inducible cell-free HIV-1 RNA in CD4+ T-cells by a prostratin analogue stimulation assay. HIV serology was quantified by signal-to-cutoff ratio (S/CO). RESULTS Of 228 enrolled participants, 69 achieved SVS for ≥5 years. HIV-1 DNA, inducible cell-free HIV-1 RNA, and S/COs correlated directly with the age of effective combination antiretroviral therapy (cART) initiation (P < .001, P = .036, and P < .001, respectively) and age when SVS was achieved (P = .002, P = .038, and P < .001, respectively) and inversely with the proportion of life spent on effective cART (P < .001, P = .01, and P < .001, respectively) and proportion of life spent with SVS (P < .001, P = .079, and P < .001, respectively). Inducible cell-free HIV-1 RNA correlated with HIV-1 DNA, most particularly in children with SVS, without virologic blips, that was achieved with the first cART regimen initiated prior to 6 months of age (rho = 0.74; P = .037) or later (rho = 0.87; P < .001). S/COs correlated with HIV-1 DNA (P = .003), but less so with inducible cell-free HIV-1 RNA (P = .09). CONCLUSIONS The prostratin analogue stimulation assay, with its lower blood volume requirement, could be a valuable method for evaluating inducible HIV-1 reservoirs in children. Standard commercial HIV serology may be a practical initial indirect measure of reservoir size in the peripheral blood of children with perinatally acquired HIV-1 infection.
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Cavin-2 Functions as a Suppressive Regulator in TNF-induced Mesenchymal Stromal Cell Inflammation and Angiogenic Phenotypes. Int J Stem Cells 2017; 10:103-113. [PMID: 28024316 PMCID: PMC5488782 DOI: 10.15283/ijsc16032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/24/2016] [Indexed: 12/12/2022] Open
Abstract
Tumour necrosis factor (TNF)-α activation of mesenchymal stromal cells (MSC) enhances their tumour-suppressive properties and tumour-homing ability. The molecular actors involved are unknown. We found that TNF induced MSC migration and tubulogenesis which correlated with a dose-dependent increase in Cavin-1 and Cavin-3 transcript levels. TNF triggered cyclooxygenase (COX)-2 expression, whereas specific siRNA-mediated gene silencing of Cavin-2 resulted in an amplified COX-2 expression, tubulogenesis, and migratory response partially due to a rapid and sustained increase in NF-κB phosphorylation status. Our results highlight a suppressive role for the caveolar component Cavin-2 in the angiogenic and inflammatory regulation of TNF-activated MSC.
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A Role for the Cavin-3/Matrix Metalloproteinase-9 Signaling Axis in the Regulation of PMA-Activated Human HT1080 Fibrosarcoma Cell Neoplastic Phenotype. CANCER GROWTH AND METASTASIS 2014; 7:43-51. [PMID: 25520561 PMCID: PMC4260767 DOI: 10.4137/cgm.s18581] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Revised: 11/17/2014] [Accepted: 11/19/2014] [Indexed: 12/15/2022]
Abstract
Caveolae are specialized cell membrane invaginations known to regulate several cancer cell functions and oncogenic signaling pathways. Among other caveolar proteins, they are characterized by the presence of proteins of the cavin family. In this study, we assessed the impact of cavin-1, cavin-2, and cavin-3 on cell migration in a human HT-1080 fibrosarcoma model. We found that all cavin-1, -2 and -3 transcripts were expressed and that treatment with phorbol 12-myristate 13-acetate (PMA), which is known to prime cell migration and proliferation, specifically upregulated cavin-3 gene and protein expression. PMA also triggered matrix metalloproteinase (MMP)-9 secretion, but reduced the global cell migration index. Overexpression of recombinant forms of the three cavins demonstrated that only cavin-3 was able to reduce basal cell migration, and this anti-migratory effect was potentiated by PMA. Interestingly, cavin-3 overexpression inhibited PMA-induced MMP-9, while cavin-3 gene silencing led to an increase in MMP-9 gene expression and secretion. Furthermore, recombinant cavin-3 significantly prevented PMA-mediated dephosphorylation of AKT, a crucial regulator in MMP-9 transcription. In conclusion, our results demonstrate that cellular cavin-3 expression may repress MMP-9 transcriptional regulation in part through AKT. We suggest that the balance in cavin-3-to-MMP-9 expression regulates the extent of extracellular matrix degradation, confirming the tumor-suppressive role of cavin-3 in controlling the invasive potential of human fibrosarcoma cells.
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Ciblage pharmacologique de la MT1-MMP dans les cellules tumorales cérébrales par l’actinonine, un inhibiteur de l’aminopeptidase N/CD13. BIO TRIBUNE MAGAZINE 2011; 38:39-45. [DOI: 10.1007/s11834-011-0042-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/01/2023]
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Altération de la réponse des cellules endothéliales cérébrales radiorésistantes aux facteurs de croissances tumoraux. Neurochirurgie 2007. [DOI: 10.1016/j.neuchi.2007.09.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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L’EGCg du thé vert potentialise la mort des cellules endothéliales cérébrales induite par l’irradiation. Neurochirurgie 2006. [DOI: 10.1016/s0028-3770(06)71281-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Activation of the extracellular signal-regulated protein kinase (ERK) cascade by membrane-type-1 matrix metalloproteinase (MT1-MMP). FEBS Lett 2001; 507:231-6. [PMID: 11684104 DOI: 10.1016/s0014-5793(01)02985-4] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The mechanisms underlying membrane-type-1 matrix metalloproteinase (MT1-MMP)-dependent induction of cell migration were investigated. Overexpression of MT1-MMP induced a marked increase in cell migration, this increase being dependent on the presence of the cytoplasmic domain of the protein. MT1-MMP-dependent migration was inhibited by a mitogen-activated protein kinase kinase 1 inhibitor, suggesting the involvement of the extracellular signal-regulated protein kinase (ERK) cascade in the induction of migration. Accordingly, MT1-MMP overexpression induced the activation of ERK, this process being also dependent on the presence of its cytoplasmic domain. MT1-MMP-induced activation of both migration and ERK required the catalytic activity of the enzyme as well as attachment of the cells to matrix proteins. The MT1-MMP-dependent activation of ERK was correlated with the activation of transcription through the serum response element, whereas other promoters were unaffected. Taken together, these results indicate that MT1-MMP trigger important changes in cellular signal transduction events, leading to cell migration and to gene transcription, and that these signals possibly originate from the cytoplasmic domain of the protein.
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Calmodulin inhibitors trigger the proteolytic processing of membrane type-1 matrix metalloproteinase, but not its shedding in glioblastoma cells. Biochem J 2001; 359:325-33. [PMID: 11583578 PMCID: PMC1222150 DOI: 10.1042/0264-6021:3590325] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Most transmembrane proteins are subjected to limited proteolysis by cellular proteases, and stimulation of cleavage of membrane proteins by calmodulin (CaM) inhibitors was recently shown. The present study investigated the ability of several CaM inhibitors to induce the proteolytic cleavage of the membrane type-1 matrix metalloproteinase (MT1-MMP) from the cell surface of highly invasive U-87 glioblastoma cells. Although no shedding of a soluble MT1-MMP form was induced by CaM inhibitors in the conditioned media, we showed that these inhibitors induced MT1-MMP proteolytic processing to the 43 kDa membrane-bound inactive form that was not correlated with an increase in proMMP-2 activation but rather with an increase in tissue inhibitor of MMPs (TIMP)-2 expression levels. Moreover, this proteolytic processing was sensitive to marimastat suggesting the involvement of MMPs. Interestingly, CaM inhibitors antagonized concanavalin A- and cytochalasin D-induced proMMP-2 activation, and affected the cytoskeletal actin organization resulting in the loss of migratory potential of U-87 glioblastoma cells. Cytoplasmic tail-truncated MT1-MMP constructs expressed in COS-7 cells were also affected by CaM inhibitors suggesting that these inhibitors stimulated MT1-MMP proteolytic processing by mechanisms independent of the CaM-substrate interaction. We also propose that TIMP-2 acts as a negative regulator of MT1-MMP-dependent activities promoted by the action of CaM inhibitors in U-87 glioblastoma cells.
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Abstract
Membrane-type 1 matrix metalloproteinase (MT1-MMP) is a membrane-associated MMP that has been recently reported to have a central role in tumour cell invasion. Here we report that both the native and overexpressed recombinant forms of MT1-MMP are highly enriched in low-density Triton X-100-insoluble membrane domains that contain the caveolar marker protein caveolin 1. Moreover, the MT1-MMP-dependent activation of proMMP-2 induced by concanavalin A and cytochalasin D was correlated with the processing of MT1-MMP to its proteolytically inactive 43 kDa fragment in U-87 glioblastoma and HT-1080 fibrosarcoma tumour cell lines; this processing was also preferentially observed within the caveolar fraction. Interestingly, whereas the expression of caveolin 1 had no effect on the MT1-MMP-dependent activation of proMMP-2, its co-expression with MT1-MMP antagonized the MT1-MMP-increased migratory potential of COS-7 cells. Taken together, our results provide evidence that MT1-MMP is preferentially compartmentalized and proteolytically processed in caveolae of cancer cells. The inhibition of MT1-MMP-dependent cell migration by caveolin 1 also suggests that the localization of MT1-MMP to caveolin-enriched domains might have an important function in the control of its enzymic activity.
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Rapid activation of matrix metalloproteinase-2 by glioma cells occurs through a posttranslational MT1-MMP-dependent mechanism. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1497:341-50. [PMID: 10996658 DOI: 10.1016/s0167-4889(00)00071-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Matrix metalloproteinase-2 (MMP-2) has been suggested to play a crucial role in tumor invasion and angiogenesis. In order to understand the mechanisms underlying proMMP-2 activation, we compared the biochemical and cellular events triggered by two potent MMP-2 activators, the lectin concanavalin A (ConA) and the cytoskeleton disrupting agent cytochalasin D (CytoD). Incubation of U87 human glioma cells for 24 h in the presence of ConA or CytoD induced a marked activation of proMMP-2 and this activation was correlated in both cases with an increase in the mRNA levels of MT1-MMP. At the protein level, proMMP-2 activation induced by CytoD or ConA strongly correlated with the appearance of a 43-kDa MT1-MMP proteolytic breakdown product in cell lysates. Interestingly, CytoD also induced a very rapid (2 h) activation of proMMP-2 that was independent of protein synthesis. Under these conditions, CytoD also promoted the rapid proteolytic breakdown of the 63 kDa pro form of MT1-MMP, resulting in the appearance of the 43 kDa MT1-MMP processed form. Overexpression of a recombinant full-length MT1-MMP protein in glioma cells resulted in the activation of proMMP-2 that was correlated with the generation of the 43 kDa fragment of the protein. By contrast, overexpression of the protein in COS-7 cells promoted proMMP-2 activation without inducing the production of the 43 kDa fragment. These results thus suggest that activation of proMMP-2 occurs through both translational and post-translational mechanisms, both involving proteolytic processing of membrane-associated MT1-MMP. This processing of MT1-MMP is, however, not essential to proMMP-2 activation but may represent a regulatory mechanism to control the activity of MT1-MMP.
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Ontogeny of the catalytic subunit and putative glucose-6-phosphate transporter proteins of the rat microsomal liver glucose-6-phosphatase system. Metabolism 2000; 49:1200-3. [PMID: 11016904 DOI: 10.1053/meta.2000.7714] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The catalytic subunit (p36) and putative glucose-6-phosphate (G6P) transporter (p46) protein levels of the rat glucose-6-phosphatase (G6Pase) system were studied in relation to G6Pase hydrolytic activity and G6P uptake in liver microsomes during the fetal to neonatal period. The mean G6P hydrolytic activity in liver microsomes increased significantly from the 20th to 21st day of gestation (from 6 to 22 mU/mg protein) and was further enhanced by 3-fold 6 hours after birth, with a maximal activity at 1 day of age (112 mU/mg protein). In contrast, G6P uptake into the vesicles was undetectable before birth, appeared after day 1 (656 pmol/mg protein), and decreased after day 2 (about 330 pmol/mg protein). Immunoblot analysis showed that the mean p36 protein level was low (< 1.6 arbitrary units [AU]) during gestation, increased sharply (to about 4.0 AU) during the first day, and remained stable afterward. Unlike p36, p46 protein was present before birth at values comparable to those postpartum. P46 increased from 3.2 AU at 20 days to 4.6 AU at 21 days of gestation, and decreased transiently after birth. These results show that (1) G6Pase hydrolytic activity before birth can occur without detectable G6P uptake function; (2) the presence of the putative G6P transporter protein is not sufficient to elicit G6P uptake; and (3) full G6Pase activity requires optimal expression of both p36 and p46 proteins. These data are discussed in relation to the function of G6Pase.
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Cloning and characterization of cDNAs encoding a candidate glycogen storage disease type 1b protein in rodents. J Biol Chem 1998; 273:31656-60. [PMID: 9822626 DOI: 10.1074/jbc.273.48.31656] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glycogen storage disease type 1 (GSD-1) is a group of genetic disorders caused by a deficiency in the activity of the enzyme glucose-6-phosphatase. (G6Pase). GSD-1a and GSD-1b, the two major subgroups, have been confirmed at the molecular genetic level. The gene responsible for GSD-1b maps to human chromosome 11q23 and a candidate human GSD-1b cDNA that encodes a microsomal transmembrane protein has been identified. In this study, we show that this cDNA maps to chromosome 11q23; thus it is a strong candidate for GSD-1b. Furthermore, we isolated and characterized candidate murine and rat GSD-1b cDNAs. Both encode transmembrane proteins sharing 93-95% sequence homology to the human GSD-1b protein. The expression profiles of murine GSD-1b and G6Pase differ both in the liver and in the kidney; the GSD-1b transcript appears before the G6Pase mRNA during development. In addition to G6Pase deficiency, GSD-1b patients suffer neutropenia, neutrophil dysfunction, and recurrent bacterial infections. Interestingly, although the G6Pase mRNA is expressed primarily in the liver, kidney, and intestine, the GSD-1b mRNA is expressed in numerous tissues, including human neutrophils/monocytes.
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Abstract
Deficiency of microsomal glucose-6-phosphatase (G6Pase), the key enzyme in glucose homeostasis, causes glycogen storage disease type 1a, an autosomal recessive disorder. Characterization of the transmembrane topology of G6Pase should facilitate the identification of amino acid residues contributing to the active site and broaden our understanding of the effects of mutations that cause glycogen storage disease type 1a. Using N- and C-terminal tagged G6Pase, we show that in intact microsomes, the N terminus is resistant to protease digestion, whereas the C terminus is sensitive to such treatment. Our results demonstrate that G6Pase possesses an odd number of transmembrane helices, with its N and C termini facing the endoplasmic reticulum lumen and the cytoplasm, respectively. During catalysis, a phosphoryl-enzyme intermediate is formed, and the phosphoryl acceptor in G6Pase is a His residue. Sequence alignment suggests that mammalian G6Pases, lipid phosphatases, acid phosphatases, and a vanadium-containing chloroperoxidase (whose tertiary structure is known) share a conserved phosphatase motif. Active-site alignment of the vanadium-containing chloroperoxidase and G6Pases predicts that Arg-83, His-119, and His-176 in G6Pase contribute to the active site and that His-176 is the residue that covalently binds the phosphoryl moiety during catalysis. This alignment also predicts that Arg-83, His-119, and His-176 reside on the same side of the endoplasmic reticulum membrane, which is supported by the recently predicted nine-transmembrane helical model for G6Pase. We have previously shown that Arg-83 is involved in positioning the phosphate during catalysis and that His-119 is essential for G6Pase activity. Here we demonstrate that substitution of His-176 with structurally similar or dissimilar amino acids inactivates the enzyme, suggesting that His-176 could be the phosphoryl acceptor in G6Pase during catalysis.
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Abstract
Glycogen-storage disease type 1 (GSD-1), also known as "von Gierke disease," is caused by a deficiency in microsomal glucose-6-phosphatase (G6Pase) activity. There are four distinct subgroups of this autosomal recessive disorder: 1a, 1b, 1c, and 1d. All share the same clinical manifestations, which are caused by abnormalities in the metabolism of glucose-6-phosphate (G6P). However, only GSD-1b patients suffer infectious complications, which are due to both the heritable neutropenia and the functional deficiencies of neutrophils and monocytes. Whereas G6Pase deficiency in GSD-1a patients arises from mutations in the G6Pase gene, this gene is normal in GSD-1b patients, indicating a separate locus for the disorder in the 1b subgroup. We now report the linkage of the GSD-1b locus to genetic markers spanning a 3-cM region on chromosome 11q23. Eventual molecular characterization of this disease will provide new insights into the genetic bases of G6P metabolism and neutrophil-monocyte dysfunction.
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Evidence that the transit of glucose into liver microsomes is not required for functional glucose-6-phosphatase. Biochem Biophys Res Commun 1997; 236:808-13. [PMID: 9245738 DOI: 10.1006/bbrc.1997.6979] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We show that the production of glucose from glucose-6-phosphate hydrolysis outside microsomes is a function of glucose-6-phosphatase independent of its property to form glucose inside microsomes. Indeed, during development (before 1 day of age), mouse liver microsomes had glucose-6-phosphatase producing glucose solely outside microsomes. Furthermore, in vivo treatment of rats with the glucocorticoid analogue triamcinolone resulted in increased glucose-6-phosphatase activity outside but not inside microsomes and without change in the catalytic subunit 40 kDa glucose-6-phosphatase mRNA abundance or protein level, indicating that other factors induced by triamcinolone (e.g., altered membrane lipid environment and/or a regulatory protein) were responsible for the activity change. Triamcinolone treatment also lessened the inhibition of glucose-6-phosphatase by pyridoxal 5'-phosphate (PLP), but this effect was not due to an interaction of PLP with the active site. Accordingly, reversal of the inhibition was observed after permeabilization of the microsomes. The two distinct orientations of liver microsomal glucose-6-phosphate phosphohydrolase suggest different physiological roles played by this enzyme in the endoplasmic reticulum membrane.
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Abstract
Glucose transport was investigated in rat liver microsomes in relation to glucose 6-phosphatase (Glu-6-Pase) activity using a fast sampling, rapid filtration apparatus. 1) The rapid phase in tracer uptake and the burst phase in glucose 6-phosphate (Glu-6-P) hydrolysis appear synchronous, while the slow phase of glucose accumulation occurs during the steady-state phase of glucose production. 2) [14C]Glucose efflux from preloaded microsomes can be observed upon addition of either cold Glu-6-P or Glu-6-Pase inhibitors, but not cold glucose. 3) Similar steady-state levels of intramicrosomal glucose are observed under symmetrical conditions of Glu-6-P or vanadate concentrations during influx and efflux experiments, and those levels are directly proportional to Glu-6-Pase activity. 4) The rates of both glucose influx and efflux are characterized by t1/2 values that are independent of Glu-6-P concentrations. 5) Glucose efflux in the presence of saturating concentrations of vanadate was not blocked by 1 mM phloretin, and the initial rates of efflux appear directly proportional to intravesicular glucose concentrations. 6) It is concluded that glucose influx into microsomes is tightly linked to Glu-6-Pase activity, while glucose efflux may occur independent of hydrolysis, so that microsomal glucose transport appears unidirectional even though it can be accounted for by diffusion only over the accessible range of sugar concentrations.
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Histone II-A stimulates glucose-6-phosphatase and reveals mannose-6-phosphatase activities without permeabilization of liver microsomes. Biochem J 1995; 310 ( Pt 1):221-4. [PMID: 7646448 PMCID: PMC1135876 DOI: 10.1042/bj3100221] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effect of histone II-A on glucose-6-phosphatase and mannose-6-phosphatase activities was investigated in relation to microsomal membrane permeability. It was found that glucose-6-phosphatase activity in histone II-A-pretreated liver microsomes was stimulated to the same extent as in detergent-permeabilized microsomes, and that the substrate specificity of the enzyme for glucose 6-phosphate was lost in histone II-A-pretreated microsomes, as [U-14C]glucose-6-phosphate hydrolysis was inhibited by mannose 6-phosphate and [U-14C]mannose 6-phosphate hydrolysis was increased. The accumulation of [U-14C]glucose from [U-14C]glucose 6-phosphate into untreated microsomes was completely abolished in detergent-treated vesicles, but was increased in histone II-A-treated microsomes, accounting for the increased glucose-6-phosphatase activity, and demonstrating that the microsomal membrane was still intact. The stimulation of glucose-6-phosphatase and mannose-6-phosphatase activities by histone II-A was found to be reversed by EGTA. It is concluded that the effects of histone II-A on glucose-6-phosphatase and mannose-6-phosphatase are not caused by the permeabilization of the microsomal membrane. The measurement of mannose-6-phosphatase latency to evaluate the intactness of the vesicles is therefore inappropriate.
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Opposite effects of hyperglycemia and insulin deficiency on liver glycogen synthase phosphatase activity in the diabetic rat. Diabetes 1993; 42:363-6. [PMID: 8381096 DOI: 10.2337/diab.42.2.363] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The specific effect of hyperglycemia on the reported decrease in liver glycogen synthase phosphatase activity was studied in STZ-induced diabetic rats with normal fasting insulinemia. Four groups of animals were investigated: control (nondiabetic), diabetic hyperglycemic (STZ), diabetic normoglycemic (STZ followed by 3-day phloridzin treatment), and a diabetic normoglycemic group injected with glucose to reinstate hyperglycemia. None of the treatments significantly altered fasting plasma insulin and glucagon concentrations. We found that hepatic synthase phosphatase activity decreased in STZ-induced diabetic rats and was further markedly reduced when glycemia was normalized in the diabetic animals. This additional decrease in phosphatase activity was almost fully reversed when hyperglycemia was restored by acute glucose infusion of the normoglycemic diabetic rats. In parallel, the levels of liver G6P and F6P were markedly reduced in the diabetic normoglycemic rats and restored with reinstatement of hyperglycemia. In contrast, liver microsomal glucose-6-phosphatase activity was enhanced and glucokinase activity was lowered in all diabetic groups, regardless of glycemia. Our results indicate that hyperglycemia per se counteracts part of the loss of hepatic synthase phosphatase in diabetic animals and provokes the stable conversion of synthase phosphatase from a less active to a more active form.
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Le système glucose-6 phosphatase hépatique : composantes, propriétés cinétiques, régulation et déficit. Med Sci (Paris) 1993. [DOI: 10.4267/10608/2964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Modulation by protein kinase C of the hormonal responsiveness of hepatocytes from lean (Fa/fa?) and obese (fa/fa) Zucker rats. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1135:221-5. [PMID: 1616941 DOI: 10.1016/0167-4889(92)90140-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effect of phorbol myristate acetate (PMA) on the hormonal responsiveness of hepatocytes from lean and obese Zucker rats was studied. Phenylephrine-stimulated phosphatydylinositol labeling and phosphorylase activation were antagonized by PMA in cells from obese and lean animals; bigger residual effects were observed in cells from obese animals even at high PMA concentrations. Cyclic AMP accumulation induced by isoproterenol, glucagon, forskolin and cholera toxin was higher in cells from lean animals than in those from obese rats. PMA diminished glucagon- and cholera toxin-induced cyclic AMP accumulation; cells from lean animals were more sensitive to PMA. Two groups of isoforms of protein kinase C (PKC) were observed in hepatocytes from Zucker rats using DEAE-cellulose column chromatography: PKC 1 and PKC 2. The PKC 1 isozymes were separated into four peaks using hydroxylapatite: aa, 1a (PKC-beta), 1b (PKC-alpha) and 1c. Short treatment with PMA decreased the activity of PKC 1 (peaks 1b (PKC-alpha) and 1c) and to a lesser extent of PKC 2; cells from lean animals were more sensitive to PMA than those obtained from obese rats. Our results indicate that cells from genetically obese Zucker rats are in general less sensitive to this activator of protein kinase C than those from their lean littermates. The possibility that alterations in the phosphorylation/dephosphorylation cycles, that control metabolism and hormonal responsiveness, may contribute to this obese state is suggested.
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[Subvalvular aortic stenosis (apropos of 50 cases: diagnostic factors)]. LA TUNISIE MEDICALE 1986; 64:803-8. [PMID: 3824537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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[Cardiocirculatory manifestations in anemia]. LA TUNISIE MEDICALE 1982; 60:41-4. [PMID: 7147371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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