Purpose: RECK, a membrane-anchored regulator of matrix metalloproteinases (MMPs), is widely expressed in healthy tissue, whereas it is expressed at lower levels in many tumor-derived cell lines. Studies in mice and cultured cells have shown that restoration of RECK expression inhibits tumor invasion, metastasis, and angiogenesis. However, the clinical relevance of these findings remains to be fully documented. Here we examined the expression of RECK and one of its targets, MMP-9, in colorectal cancer tissue.Experimental Design: The RECK and MMP-9 expression levels in colorectal cancer samples from 53 patients were determined by immunohistochemical techniques. The expression level of each protein was scored, and the patients were divided into two groups based on these scores. In 33 cases, we performed gelatin zymography to estimate the degree of MMP-2 and MMP-9 activation. Microvessel density and vascular endothelial growth factor (VEGF) expression were also evaluated histologically.Results: RECK protein was detected in 30 of 53 (56.6%) specimens. Importantly, patients with tumors expressing relatively high levels of RECK (high-RECK group) had a significantly lower risk of recurrence than did patients with tumors expressing relatively low levels of RECK (low-RECK group; P ؍ 0.011). Moreover, RECK-dominant (RECK score > MMP-9 score) patients showed a significantly lower incidence of recurrence than did MMP-9-dominant patients (P ؍ 0.0003). Multivariate analysis revealed that the RECK/MMP-9 balance was an independent prognostic factor (P ؍ 0.0122). The expression of VEGF and microvessel density were inversely correlated with the level of RECK expression.Conclusions: RECK/MMP-9-balance is an informative prognostic indicator for colorectal cancer. Our data also suggest that RECK suppresses tumor angiogenesis, probably by limiting the availability of VEGF in tumor tissues.
Leucine has been shown to stimulate adipose tissue protein synthesis in vivo as well as leptin secretion, protein synthesis, hyper-plastic growth, and tissue morphogenesis in in vitro experiments using freshly isolated adipocytes. Recently, others have proposed that leucine oxidation in the mitochondria may be required to activate the mammalian target of rapamycin (mTOR), the cytosolic Ser/Thr protein kinase that appears to mediate some of these effects. The first irreversible and rate-limiting step in leucine oxidation is catalyzed by the branched-chain α-keto acid dehydrogenase (BCKD) complex. The activity of this complex is regulated acutely by phosphorylation of the E1α-subunit at Ser293 (S293), which inactivates the complex. Because the α-keto acid of leucine regulates the activity of BCKD kinase, it has been suggested as a potential target for leucine regulation of mTOR. To study the regulation of BCKD phosphorylation and its potential link to mTOR activation, a phosphopeptide-specific antibody recognizing this site was developed and characterized. Phospho-S293 (pS293) immunoreactivity in liver corresponded closely to diet-induced changes in BCKD activity state. Immunoreactivity was also increased in TREMK-4 cells after the induction of BCKD kinase by a drug-inducible promoter. BCKD S293 phosphorylations in adipose tissue and gastrocnemius (which is mostly inactive in vivo) were similar. This suggests that BCKD complex in epididymal adipose tissue from food-deprived rats is mostly inactive (unable to oxidize leucine), as is the case in muscle. To begin to test the leucine oxidation hypothesis of mTOR activation, the dose-dependent effects of orally administered leucine on acute activation of S6K1 (an mTOR substrate) and BCKD were compared using the pS293 antibodies. Increasing doses of leucine directly correlated with increases in plasma leucine concentration. Phosphorylation of S6K1 (Thr389, the phosphorylation site leading to activation) in adipose tissue was maximal at a dose of leucine that increased plasma leucine approximately threefold. Changes in BCKD phosphorylation state required higher plasma leucine concentrations. The results seem more consistent with a role for BCKD and BCKD kinase in the activation of leucine metabolism/oxidation than in the activation of the leucine signal to mTOR.
The aim of the present study was to analyze the neuromodulation of rectoanal reflex activity by lumbar sympathetic nerves in guinea pigs. The mechanical activities of the rectum were recorded with a balloon connected to a pressure transducer, and those of the internal anal sphincter (IAS) were recorded with a custom-made strain gauge force transducer. Gradual and sustained rectal distension evoked the rectoanal reflex, causing cholinergic contractions of the rectum and synchronous nitrergic relaxations of the IAS. Section of the lumbar colonic nerves enhanced both rectal contractions and IAS relaxations. Section of the 13th thoracic cord abolished both rectal contractions and IAS relaxations, but section of the lumbar colonic nerves restored them. Lumbar sympathectomy and pithing sacral cords greatly diminished these rectal contractions and IAS relaxations, but the intrinsic reflex component remained. N G -nitro-L-arginine methyl ester enhanced the intrinsic reflex-mediated contraction of the rectum and abolished reflex-mediated relaxation of the IAS and converted into cholinergic contractions. The present results indicate that the extrinsic lumbar inhibitory outflow causes marked inhibition of the rectoanal reflex via the lumbar colonic nerves. extrinsic reflex; internal anal sphincter; intrinsic reflex; pelvic nerves; rectum WE HAVE PREVIOUSLY REPORTED (22) that a rectorectal reflex is induced by prompt rectal distension in the guinea pig. This rectorectal reflex is composed of the extrinsic excitatory reflex via sacral cords (S1-3), the extrinsic inhibitory reflex via lumbar cords (L1-4), and the intrinsic cholinergic excitatory reflex via the enteric nervous system (22). The afferent and efferent limbs of the extrinsic excitatory reflex travel in the pelvic nerves, whereas the limbs of the extrinsic inhibitory reflex pass in the lumbar colonic nerves (LCNs) (22). Furthermore, we have found that the inhibitory reflex is suppressed by descending input from the pontine defecation center, leading to a disinhibition of the sacral excitatory reflex and intrinsic excitatory reflex (22)(23)(24). In view of these findings, we have proposed that the lumbar colonic inhibitory reflex contributes to the rectorectal reflex, one important component of the defecation reflex (22-25).To clarify the integrative control of the defecation reflex by the lumbar sympathetic nerves, the goal of the present study was to elucidate the rectoanal reflex [especially the rectointernal anal sphincter (recto-IAS) reflex], because the act of defecation is a consequence of successive phenomena occurring in both the colon and anorectum (9). There is considerable evidence to support the view that the descending inhibitory reflex involving inhibitory motor neurons occurs along the entire large intestine (1, 2, 6, 7). In the current study, the rectoanal reflex (especially the recto-IAS reflex) was analyzed, and the role of the lumbar sympathetic nerves in integrative control of the distension-induced rectoanal reflex was evaluated. METHODS AND MA...
Lap-IGFI can noninvasively provide detailed lymph and blood flow information and is a useful device to aid in the accurate identification of individual patients' lymph drainage. This helps dictate adequate lymphadenectomy and the extent of intestinal resection in Lap-CRC surgery.
A 69-year-old man was diagnosed as having myasthenia gravis (MG) in September 2004, and treated with thymectomy and prednisolone. He was then diagnosed as having steroid-induced diabetes mellitus, and received sulfonylurea (SU) therapy in May 2005. An alpha-glucosidase inhibitor (alphaGI) was added in March 2006, resulting in good glycemic control. He experienced symptoms of abdominal distention, increased flatus, and constipation in October 2007, and was admitted into our hospital in late November with hematochezia. Plain abdominal radiography revealed small linear radiolucent clusters in the wall of the colon. Computed tomography (CT) showed intramural air in the sigmoid colon. Colonoscopy revealed multiple smooth surfaced hemispherical protrusions in the sigmoid colon. The diagnosis of pneumatosis cystoides intestinalis (PCI) was made on the basis of these findings. As the alphaGI voglibose was suspected as the cause of this patient's PCI, treatment was conservative, ceasing voglibose, with fasting and fluid supplementation. The patient progressed well, and was discharged 2 wk later. Recently, several reports of PCI associated with alphaGI therapy have been published, predominantly in Japan where alphaGIs are commonly used. If the use of alphaGIs becomes more widespread, we can expect more reports of this condition on a global scale. The possibility of PCI should be considered in diabetic patients complaining of gastrointestinal symptoms, and the gastrointestinal tract should be thoroughly investigated in these patients.
A new possibility for repairing the anal dysfunction by promoting regeneration of the reflex pathways in the enteric nervous system. Am J Physiol Gastrointest Liver Physiol 294: G1084-G1093, 2008. First published February 28, 2008 doi:10.1152/ajpgi.00345.2007.-Moderate rectal distension elicits recto-rectal reflex contractions and simultaneous rectointernal anal sphincter reflex relaxations that together comprise the defecation reflex. Both reflexes are controlled by 1) pelvic nerves, 2) lumbar colonic nerves, and 3) enteric nervous system. The aim of the present study was to explore a novel approach to repairing the defecation reflex dysfunction by using the plasticity of enteric nervous pathways. Experiments were performed in anesthetized guinea pigs with ethyl carbamate. The rectum 30 mm oral from the anal verge was transected without damage to extrinsic nerves, and subsequent endto-end one-layer anastomosis was performed. Recovery of the defecation reflex and associated reflex pathways were evaluated. Eight weeks after sectioning of intrinsic reflex nerve pathways in the rectum, the defecation reflex recovered to the control level, accompanied with regeneration of reflex pathways. The 5-HT 4-receptor agonist mosapride (0.5 and 1.0 mg/kg) significantly (P Ͻ 0.01) enhanced the recovered defecation reflex 8 wk after surgery. Two weeks after local treatment with brain-derived neurotrophic factor (BDNF: 10 Ϫ6 g/ml) at the rectal anastomotic site, the recto-internal anal sphincter reflex relaxations recovered and some bundles of fine nerve fibers were shown to interconnect the oral and anal ends of the myenteric plexus. These results suggested a possibility for repairing the anal dysfunction by promoting regeneration of the reflex pathways in the enteric nervous system with local application of BDNF.brain-derived neurotrophic factor; internal anal sphincter THE DEFECATION REFLEX, which can be elicited by moderate rectal distension, involves simultaneous recto-rectal contractions (R-R reflex) and recto-internal anal sphincter reflex relaxation (R-IAS reflex). These coordinated responses involve both extrinsic reflexes via autonomic nervous system and intrinsic reflexes via enteric nervous system (17, 19 -21, 26). The plasticity of these intrinsic reflex pathways has been shown in models involving chronic destruction of lumbar and sacral cords in guinea pig (9, 10). After the lower anterior resection for rectal cancer, however, long-lasting defecation disturbances occur in many patients owing to the impairment of reflex pathways.Recently, we have reported that the 5-HT 4 receptor agonist mosapride enhances the intrinsic R-R and R-IAS reflexes in the spinal cord injury model as well as in intact guinea pigs. This indicates that 5-HT 4 -receptor activation can enhance intrinsic R-R and R-IAS reflexes that are functionally compromised after deprivation of extrinsic nerves and that this action is mediated through intrinsic pathways (9, 10). Accordingly, following lower anterior resection, mosapride can enhance the refl...
Distension-evoked reflex of rectorectal (R-R) contractions and rectointernal anal sphincter (R-IAS) relaxations can be generated in guinea pigs through an extrinsic sacral excitatory neural pathway (pelvic nerves) as well as intrinsic cholinergic excitatory and nitrergic inhibitory pathways. The aim of the present study was to create intrinsic R-R and R-IAS reflex models by pithing (destruction of the lumbar and sacral cords; PITH) and to evaluate whether the prokinetic benzamide mosapride, a 5-HT(4) receptor agonist, enhances these reflexes. The mechanical activities of the R-R and R-IAS were recorded in the anesthetized guinea pig on days 2-9 after PITH. Although the basal rectal pressure at distension after PITH was significantly lower than control, the reflex indexes of R-R contractions and synchronous R-IAS relaxations were unchanged between days 4 and 9 after PITH. The frequency of spontaneous rectal and IAS motility were also unchanged. Immunohistochemical studies revealed that the distribution of myenteric and intramuscular interstitial cells of Cajal (ICC) were not altered after PITH. Mosapride (0.1-1.0 mg/kg iv) dose-dependently increased both intrinsic R-R (maximum: 1.82) and R-IAS reflex indexes (maximum: 2.76) from control (1.0) 6-9 days after PITH. The 5-HT(4) receptor antagonist, GR-113808 (1.0 mg/kg iv) decreased the R-R and R-IAS reflex indexes by approximately 50% and antagonized the effect of mosapride (1.0 mg/kg iv). The present results indicate that mosapride moderately enhanced intrinsic R-R and R-IAS reflexes functionally compensated after deprivation of extrinsic nerves, mediated through endogenously active intrinsic 5-HT(4) receptors.
The rectal distension-evoked reflex rectal (R-R) contractions and internal anal sphincter (R-IAS) relaxations in guinea pigs were generated through the extrinsic sacral excitatory nerve pathway (pelvic nerves) and the intrinsic cholinergic excitatory and nitrergic inhibitory nerve pathways. The aim of the present study was to evaluate whether a prokinetic benzamide, mosapride, enhances the R-R and R-IAS reflexes mediated via 5-HT4 receptors in the guinea pig. The mechanical activities of the R and IAS were recorded with a balloon connected to a pressure transducer and a strain gauge force transducer in the anesthetized guinea pig with intact spinal-intestinal pathways. Gradual and sustained rectal distension evoked R-R contractions and synchronous R-IAS relaxations. Mosapride (0.1-1.0 mg/kg i.v.) dose-dependently enhanced both R-R and R-IAS reflex responses. Reflex indexes for R-R and R-IAS maximally increased from 1.0 (control) to 1.92 and 1.88, respectively. A specific 5-HT4 receptor antagonist, GR 113808 (1.0 mg/kg i.v.), antagonized the enhancement of the R-R and R-IAS reflexes induced by mosapride 1.0 mg/kg i.v. The present results indicate that mosapride enhanced the R-R and R-IAS reflexes mediated through 5-HT4 receptors.
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