Background-Non-steroidal anti-inflammatory drugs (NSAIDs) are eVective for arthritis but cause gastrointestinal injury. Bovine colostrum is a rich source of growth factors and is marketed as a health food supplement. Aims-To examine whether spray dried, defatted colostrum or milk preparations could reduce gastrointestinal injury caused by indomethacin. Methods-EVects of test solutions, administered orally, were examined using an indomethacin restraint rat model of gastric damage and an indomethacin mouse model of small intestinal injury. EVects on migration of the human colonic carcinoma cell line HT-29 and rat small intestinal cell line RIE-1 were assessed using a wounded monolayer assay system (used as an in vitro model of wound repair) and eVects on proliferation determined using [ H]thymidine incorporation.Results-Pretreatment with 0.5 or 1 ml colostral preparation reduced gastric injury by 30% and 60% respectively in rats. A milk preparation was much less eYcacious. Recombinant transforming growth factor added at a dose similar to that found in the colostrum preparation (12.5 ng/rat), reduced injury by about 60%. Addition of colostrum to drinking water (10% vol/vol) prevented villus shortening in the mouse model of small intestinal injury. Addition of milk preparation was ineVective. Colostrum increased proliferation and cell migration of RIE-1 and HT-29 cells. These eVects were mainly due to constituents of the colostrum with molecular weights greater than 30 kDa. Conclusions-Bovine colostrum could provide a novel, inexpensive approach for the prevention and treatment of the injurious eVects of NSAIDs on the gut and may also be of value for the treatment of other ulcerative conditions of the bowel. (Gut 1999;44:653-658)
Non-steroidal anti-inflammatory drugs (NSAIDs) are effective analgesics but cause gastrointestinal injury. Present prophylactic measures are suboptimal and novel therapies are required. Bovine colostrum is a cheap, readily available source of growth factors, which reduces gastrointestinal injury in rats and mice. We therefore examined whether spray-dried, defatted colostrum could reduce the rise in gut permeability (a non-invasive marker of intestinal injury) caused by NSAIDs in volunteers and patients taking NSAIDs for clinical reasons. Healthy male volunteers (n=7) participated in a randomized crossover trial comparing changes in gut permeability (lactulose/rhamnose ratios) before and after 5 days of 50 mg of indomethacin three times daily (tds) per oral with colostrum (125 ml, tds) or whey protein (control) co-administration. A second study examined the effect of colostral and control solutions (125 ml, tds for 7 days) on gut permeability in patients (n=15) taking a substantial, regular dose of an NSAID for clinical reasons. For both studies, there was a 2 week washout period between treatment arms. In volunteers, indomethacin caused a 3-fold increase in gut permeability in the control arm (lactulose/rhamnose ratio 0.36+/-0.07 prior to indomethacin and 1.17+/-0.25 on day 5, P<0.01), whereas no significant increase in permeability was seen when colostrum was co-administered. In patients taking long-term NSAID treatment, initial permeability ratios were low (0.13+/-0.02), despite continuing on the drug, and permeability was not influenced by co-administration of test solutions. These studies provide preliminary evidence that bovine colostrum, which is already currently available as an over-the-counter preparation, may provide a novel approach to the prevention of NSAID-induced gastrointestinal damage in humans.
Different phosphoinositides are synthesized in cell membranes in order to perform a variety of functions. One of the most abundant of these lipids is phosphatidylinositol (PI) 4-phosphate (PI4P), which is formed in human eukaryotes by type II and type III phosphatidylinositol 4-kinase (PI4K II and III) activities. PI4K II activity occurs in many different subcellular membranes, although no detailed analysis of the distribution of this activity has been reported. Using density gradient ultracentrifugation, we have previously found that in A431 cells the predominant PI4K activity arises from a type II alpha enzyme that is localized to a buoyant membrane fraction of unknown origin [Waugh, Lawson, Tan and Hsuan (1998) J. Biol. Chem. 273, 17115-17121]. We show here that these buoyant membranes contain an activated form of PI4K II alpha that can be separated from the bulk of the PI4K II alpha protein in A431 and COS-7 cells. Proteomic analysis revealed that the buoyant membrane fraction contains numerous endoplasmic reticulum (ER)-marker proteins, although it was separated from the bulk of the ER, ER-Golgi intermediate compartment, transitional ER, Golgi and other major subcellular membranes. Furthermore, the majority of the cytoplasmic valosin-containing protein (VCP), an AAA+ATPase implicated in various ER, transitional ER, Golgi and nuclear functions, was almost completely localized to the same buoyant membrane fraction. Co-localization of VCP and PI4K activity was confirmed by co-immunoprecipitation. These results suggest the previously unsuspected existence of an ER-related domain in which the bulk of the cellular PI4P synthesis and VCP are localized.
Following experimental partial hepatectomy of 70% in the rat, there is a semisynchronized surge of hepatocyte proliferation that ceases after 48 to 72 hours. Little is known about the determinants governing the termination of the proliferative phase, although transforming growth factor (TGF) beta has been implicated as an important inhibitor of hepatocyte replication in this model. We previously reported an additional non-TGF-beta inhibitor in medium conditioned by nonparenchymal cells isolated from regenerating liver (CM-NPC-Reg) between 24 and 48 hours after partial hepatectomy, but it was not found in medium conditioned by nonparenchymal cells from unoperated control liver. CM-NPC-Reg suppressed replicative DNA synthesis of primary rat hepatocytes in response to hepatocyte growth factor (HGF), epidermal growth factor (EGF), or TGF-alpha as assessed by 3H-thymidine incorporation. We now present evidence that interleukin (IL)-1 is the major inhibitor of hepatocyte DNA synthesis present in CM-NPC-Reg. IL-1 receptor antagonist abrogated the inhibition, as did antibodies to rat IL-1alpha and -beta; a combination of both antibodies was required, implicating both IL-1alpha and IL-1beta as active constituents in CM-NPC-Reg. To investigate in vivo changes in IL-1 expression, we assessed expression of IL-1alpha messenger RNA (mRNA) in whole rat liver following partial hepatectomy; mRNA was down-regulated at 10 hours in the pre-replicative phase of liver regeneration and up-regulated at 24 hours and 48 hours when proliferation is waning. Rat hepatocytes isolated from liver 24 hours after partial hepatectomy showed increased sensitivity to the inhibitory action of IL-1. Exogenous IL-1beta, administered parenterally to a group of rats at 0 and 12 hours after partial hepatectomy significantly reduced the incorporation of the thymidine analogue, bromodeoxyuridine (BrdU), into hepatocytes at 18 hours. These data indicate that nonparenchymal cells isolated from regenerating rat liver elaborate IL-1, and support the hypothesis that IL-1 plays a role suppressing hepatocyte proliferation and terminating the surge of DNA synthesis induced after partial hepatectomy.
Histidinemia in mice and in humans is an autosomal recessive disorder of histidine metabolism that leads to high-histidine levels in both plasma and urine and is caused by a lack of hepatic histidine-alpha-deaminase (histidase). We have used a novel approach to hepatocellular transplantation to effect a complete phenotypic cure of histidinemia in a mouse model. Mice lacking histidase were treated with isolated liver cells (approximately 18 x 10(6) hepatocytes and 9 x 10(6) nonparenchymal cells) from histidase-competent donors transplanted into the peritoneum (active transplant group). Recipient mice showed a dramatic decrease, by more than 75%, in urinary histidine levels from day one throughout the course of the experiment, resulting in levels within the normal range for wild-type mice. In comparison, there was no change in urinary histidine levels in the control group of histidase-deficient mice treated with isolated liver cells from mice lacking histidase (statistical comparison between the two groups, P < .003, two-way ANOVA). Histologically, ectopic liver tissue was seen in the peritoneum in association with abdominal wall, pancreas, and peritoneal connective tissue; immunohistochemical evidence showed expression of histidase in the ectopic liver tissue in the active transplant group. This report is the first to show complete correction of a defective biochemical phenotype achieved by hepatocellular transplantation.
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