POU-domain gene expression in the gastrointestinal tract

The process of self-renewal which occurs in the gastrointestinal epithelium is greatly amplified and accelerated during the intestinal adaptation which occurs in the residual ileum after massive small bowel resection (MSBR). As with growth and development, these processes must involve the coordinated regulation of many genes. Several families of nuclear proteins are known to be involved in the control of gene expression during development including the POU-domain genes; their expression has not been characterized in the gastrointestinal tract during normal cellular renewal or adaptation, and POU-domain encoding cDNAs were cloned from ileal RNA. Three known genes were cloned: Oct-1, Brn-1 and Tst-1 but no novel members of this gene family were identified. The encoded sequence for rat Oct-1 differs from that previously reported. Oct-1 is relatively ubiquitously expressed with increased expression during both development and adaptation. Minimal expression of Tst-1 was observed. Brn-1 exhibits limited expression in the adult gastrointestinal tract. but may play a role in the fetal gastrointestinal tract.     

Mineralocorticoid receptor gene expression in the gastrointestinal tract: distribution and ontogeny

The gastrointestinal tract is a well characterized target tissue for aldosterone, where it regulates electrolyte transport, particularly in the descending colon. Previous studies have demonstrated the presence of aldosterone receptors in gastrointestinal tissues. We have used specific cRNA probes for the rat mineralocorticoid receptor to explore both the distribution and ontogeny of mineralocorticoid receptor gene expression in the gastrointestinal tract. Mineralocorticoid receptor gene expression is found throughout the small and large intestine, but is absent from the stomach. The highest levels are observed in the distal colon, and significant expression is found in the duodenum; in both tissues levels of expression are higher than those in kidney. In both the developing duodenum and colon, mineralocorticoid receptor gene expression precedes the development of the full physiological response to aldosterone. These findings emphasise the colon as an important target tissue for aldosterone, and raise the question of potential roles for aldosterone in the duodenum.     

Daily rhythms of clock gene expression and feeding behavior during the larval development in gilthead seabream,Sparus aurata

Light is the main environmental time cue which synchronizes daily rhythms and the molecular clock of vertebrates. Indeed, alterations in photoperiod have profound physiological effects in fish (e.g. reproduction and early development). In order to identify the changes in clock genes expression in gilthead seabream larvae during ontogeny, three different photoperiods were tested: a regular 12L:12D cycle (LD), a continuous light 24L:0D (LL) and a two-phases photoperiod (LL?+?LD) in which the photoperiod changed from LL to LD on day 15 after hatching (dph). Larvae were sampled on 10, 18, 30 and 60 days post-hatch (dph) during a 24?h cycle. In addition to the expression of clock genes (clock, bmal1, cry1 and per3), food intake was measured. Under LD photoperiod, larvae feed intake and clock genes expression showed a rhythmic pattern with a strong light synchronization, with the acrophases occurring at the same hour in all tested ages. Under LL photoperiod, the larvae also showed a rhythmic pattern but the acrophases occurred at different times depending on the age, although at the end of the experiment (60 dph) clock genes expression and feed intake rhythms were similar to those larvae exposed to LD photoperiod. Moreover, the expression levels of bmal1 and cry1 were much lower than in LD photoperiod. Under the LL?+?LD photoperiod, the 10 dph larvae showed the same patterns as LL treatment while 18 and 30 dph larvae showed the same patterns as LD treatment. These results revealed the presence of internal factors driving rhythmic physiological responses during larvae development under constant environmental conditions. The LL?+?LD treatment demonstrates the plasticity of the clock genes expression and the strong effect of light as synchronizer in developing fish larvae.     

Kallikrein-gene expression in the rat gastrointestinal tract.

The serine proteinase glandular kallikrein has been demonstrated in the gastrointestinal tract, although there is some doubt as to whether it is synthesized there or derives from exocrine-gland secretions. Using a rat pancreatic kallikrein cRNA probe we have demonstrated kallikrein-like gene expression in the corpus, duodenum, jejunum, ileum, caecum and colon, and compared the pattern of expression with that of the gastrointestinal peptides somatostatin, gastrin and glucagon. In addition, using a panel of oligonucleotide probes specific for various members of the rat kallikrein-gene family, we have shown that the kallikrein-like gene expressed appears to be expressed as true kallikrein.     

Hormonal regulation of core clock gene expression in skeletal muscle following acute aerobic exercise

Exercise increases skeletal muscle health in part by altering the types of genes that are transcribed. Previous work suggested that glucocorticoids signal through the protein Regulated in Development and DNA Damage 1 (REDD1) to regulate gene expression following acute aerobic exercise. The present study shows that expression of the core clock gene, Period1, is among those modulated by the glucocorticoid-REDD1 signaling pathway in skeletal muscle. We also provide evidence that Aldosterone and Epinephrine contribute to the regulation of Period1 expression via REDD1. These data show that adrenal stress hormones signal through REDD1 to regulate skeletal muscle gene expression, specifically those of the core clock, following acute aerobic exercise.     

Biological clock: the oscillator of gene expression

正The 2017 Nobel prize in physiology or medicine was awarded to the discoveries of genes and molecular mechanisms of the circadian rhythm,which is any biological process that oscillates with a period of about 24 h.Three scientists from the United States,Jeffrey C.Hall,Michael Rosbash,and Michael W.Young,shared the award.This work is of great theoretical value in understanding the nature of life and the interactions of life with its environments,and also has important application value in guiding the treatment     

Cubilin expression and posttranslational modification in the canine gastrointestinal tract

Cubilin is an endocytic receptor of the apical brush border membrane that is essential for intrinsic factor-mediated cobalamin absorption in small intestine. However, cubilin is more highly expressed in kidney and yolk sac, and recent molecular characterization of the receptor has focused on these tissues. The aim of this investigation was to examine tissue-specific cubilin expression and posttranslational modifications with an emphasis on the gastrointestinal tract. Intrinsic factor-cobalamin binding activity, cubilin immunoreactivity, and cubilin mRNA levels were determined in multiple segments of canine gastrointestinal mucosa and other tissues. These aspects of cubilin expression varied in parallel, suggesting that the major determinant of regional cubilin expression in the gastrointestinal tract is modulation of cubilin mRNA. Cell fractionation indicated that ileal cubilin is not strongly membrane associated. An approximately 185-kDa brush border specific and two >400-kDa precursor forms of cubilin were identified. Asparagine-linked oligosaccharide modifications characterized by differential glycosidase digestion of affinity-purified cubilin from ileal mucosa and renal cortex differed, but ileal and renal intracellular cubilin comigrated on SDS-PAGE at approximately 400 kDa after oligosaccharide removal, thus reconciling previous conflicting size estimates of the cubilin polypeptide.     

Microecology of the gastrointestinal tract of chronic enteritis patients

The results obtained in the simultaneous study of the microbiology of different sections of the gastrointestinal tract (the oral cavity, the stomach, the large and small intestines) in chronic enteritis patients, as well as in the study of biopsy mucosa samples from the small intestine of such patients, are presented. This method has been shown to give a complete picture indicating both the severity of dysbiotic disturbances in the patient and the degree of their spread in the alimentary canal, which should be taken into account in clinical practice for the determination of the severity of the disease, the rational course of treatment and the time of the discharge of the patient from the hospital.     

去甲斑蝥素对糖尿病大鼠肾小球纤维粘连蛋白及钙调磷酸酶的影响

目的:观察去甲斑蝥索(NCTD)对链脲佐菌素(STZ)诱导的糖尿病(DM)模型大鼠肾小球纤维粘连蛋白以及钙调磷酸酶表达的影响,探讨去甲斑蝥素抗肾小球纤维化的机制.方法:10只大鼠正常饮食为正常对照组(C)组,30只大鼠给予高脂高糖饮食+链脲佐菌素(STZ)制备DM模型,随机分3组:DM模型(D)组10只,小剂量去甲斑蝥素治疗(N1)组10只,大剂量去甲斑蝥素治疗(N2)组10只,给药8周后检测血糖,血肌酐水平变化;用免疫组化法检测肾组织肾小球纤维粘连蛋白(fibronectin,FN)以及钙调磷酸酶(calcineurin,CaN)表达,分别用realtime-PCR以及western blot法检测肾组织FN以及CaN mRNA和蛋白水平的表达.结果:模型(D)组血糖,血肌酐水平上升(P<0.05),同时肾小球区FN,CaN的表达高于正常(C)组(P<0.05).去甲斑蝥素干预(N)组与模型组比较,去甲斑蝥素组肾小球区FN,CaN表达下调(P<0.05).大剂量组效果更显著(P<0.05).去甲斑蝥素(N)治疗组血糖水平,肾功能较(D)组无明显变化.结论:去甲斑蝥素能减少糖尿病大鼠肾小球区FN的表达,其作用机制可能是通过使CaN的表达下调而实现.     

Microflora of gastrointestinal tract in patients with chronic cholecystitis

AIM: Assessment of quantitative and qualitative characteristics of gastrointestinal microflora in patients with chronic cholecystitis. MATERIALS AND METHODS: Bacteriological analysis of biopsy samples of esophageal and gastric mucosae as well as stool samples was performed in 10 healthy volunteers and 28 patients with chronic cholecystitis. RESULTS: Opportunistic microorganisms are acquiring greater significance in formation of gastrointestinal microbiocenosis. Significant increase of both isolation rate and density of gastrointestinal tract colonization by staphylococci, enterobacteriae and anaerobic microorganisms was revealed. CONCLUSION: Obtained results showed abnormalities of microbiocenosis of esophageal and gastric mucosae and presence of intestinal disbacteriosis of different degrees of intensity.     

Effects of diabetes and insulin on hepatic delta6 desaturase gene expression

It has been recognized that rat liver microsomal Delta6 desaturation activity is defective in experimental diabetes, a fact that may be reverted by means of insulin treatment. In the present study, we used streptozotocin-induced diabetic rats in order to determine the regulatory role of insulin on the expression of hepatic Delta6 desaturase gene. The abundance of hepatic Delta6 desaturase mRNA in the diabetic rats is sevenfold lower than in the control. Insulin administration to diabetic rats induces Delta6 desaturase mRNA eightfold within 24 h. The effect of insulin on the Delta6 desaturase mRNA was inhibited 70% with dibutyryl-cAMP and theophylline administration and 90% by cycloheximide administration. Therefore, our data demonstrate that the activity of hepatic Delta6 desaturase in response to insulin is, at least in part, regulated by pretranslational events that require the synthesis of an unknown protein(s).     

Latent herpes simplex virus type 1 gene expression in ganglia innervating the human gastrointestinal tract.

Using in situ hybridization, we demonstrated that latent herpes simplex virus type 1 (HSV-1) gene expression is prevalent in human adult nodose ganglia. This suggests that infection of gastrointestinal sensory nerves, probably through swallowed virus-laden oral secretions, occurs commonly and that HSV-1 reactivating from this site may play a role in recurrent gastrointestinal disorders.