Lithostathine messenger RNA expression in different types of chronic pancreatitis

Bifidobacterium longum supplementation improved high-fat-fed-induced metabolic syndrome and promoted intestinal Reg I gene expression

Recent evidence suggests that intestinal Bifidobacterium species (spp.) positively correlates with improved insulin resistance and obesity, and this might be linked to metabolic inflammation. The expression of intestinal REG (regenerating) family proteins which are widely involved in inflammatory bowel disease and diabetes are still unknown in metabolic syndrome. Hence, we investigated the effects of Bifidobacterium longum (BIF) supplementation on metabolic parameters, intestinal function and expression of Reg family genes in a rat model of metabolic syndrome induced by a high-fat (HF) diet. We specifically increased the gut bifidobacterial content of HF-fed rats through BIF supplementation. Compared with the normal chow-fed control rats, HF feeding significantly reduced intestinal Bifidobacterium. As expected, BIF supplementation fed rats had totally restored quantities of Bifidobacterium. HF diet-fed rats showed significant increase in body weight, fat deposits, systolic blood pressure, fasting glucose, fasting triglycerides and reduced insulin sensitivity, while increases of intestinal Bifidobacterium did improve HF-diet-induced metabolic disorders. HF feeding led to significantly higher levels of the plasma lipopolysaccharide, interleukin-1β and intestinal myeloperoxidase, as well as intestinal inflammatory activity index, while these parameters were normalized to the control levels in the HF + BIF-treated rats. The levels of RegI mRNA and protein in the HF + BIF group were significantly higher than the control and the HF groups. Increasing Bifidobacterium in the gut improved HF-fed-induced metabolic syndrome by reducing metabolic endotoxin concentrations and intestinal inflammation, as well as upgrading the expression of intestinal Reg I as a regulator of growth factor.

RegIV potentiates colorectal carcinoma cell migration and invasion via its CRD domain

The RegIV gene is differentially expressed in cancer and noncancerous cells. In this study, we investigated the role of RegIV and its CRD domain in the invasion and migration of human colorectal carcinoma LoVo cells. Recombinant plasmids, pcDNA3.1-RegIV and pcDNA3.1-RegIV CRD, were constructed and transfected into LoVo cells. The in vivo RegIV and RegIV CRD mRNA and protein levels were then analyzed by reverse transcriptase-polymerase chain reaction and immunocytochemistry, respectively. Cell proliferation was measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and flat plate colony-forming assays, and apoptosis was measured by flow cytometry. Cell migration and invasion were assessed with a Transwell chamber. A high level of RegIV and RegIV carbohydrate-recognition domain (CRD) expression was demonstrated in RegIV and RegIV CRD-transfected cells. There were no differences in cell proliferation, colony formation, and apoptosis between the LoVo/RegIV and untreated LoVo cells (P > 0.05). However, the LoVo/RegIV cells, but not LoVo/RegIV CRD cells, displayed greater migration and invasion abilities compared to the empty vector and untreated LoVo cells. The migrated cell numbers of the LoVo/RegIV, LoVo/RegIV CRD, LoVo/empty vector, and control LoVo groups were 247.00 +/- 10.61, 146.27 +/- 6.81, 151.16 +/- 7.18, and 149.65 +/- 6.53 cells per field, respectively (P < 0.05). The invasion cell numbers of the four groups were 57.00 +/- 3.00, 31.53 +/- 2.72, 30.3 +/- 2.07, and 32.16 +/- 2.30 cells per field, respectively. RegIV enhances LoVo cell migration and invasion, and its CRD domain is critical for these effects.

Theories, mechanisms, and models of alcoholic chronic pancreatitis

Alcoholic chronic pancreatitis is a severe, disabling, chronic inflammatory condition of the pancreas that is seen in fewer than 5% of alcoholics. The severity and unpredictability of this condition has lead to several theories on the mechanism causing chronic pancreatitis based on careful clinical observation. Hypothetical mechanisms were applied to various animal models. Finally, following multiple lines of evidence, there is a convergence of thought and development of some new models that are quite instructive. Taken together, chronic alcohol consumption by rats results in multiple effects on the pancreas that increase the risk of acute pancreatitis, including ongoing acinar cell injury that lowers the threshold for hyperstimulation-induced acute pancreatitis, neurohormonal injury, and adaptation that results in acinar cell hyperstimulation, increased susceptibility to viral mediated acute pancreatitis, and possibly other factors. After acute pancreatitis initiates the inflammatory process, the chronic inflammation and fibrosis of alcoholic chronic pancreatitis are driven by diet, the acinar cell stress response to continued alcohol that may be potentiated by toxic alcohol metabolites, hypoxia, hyperstimulation, and partial duct obstruction; plus the effects of proinflammatory immunocytes and cytokines; and by stellate cell-mediated fibrosis driven by anti-inflammatory cytokines, alcohol, and alcohol metabolites. The factors determining which alcoholic will develop alcoholic chronic pancreatitis likely involve genetic factors, dietary factors, and susceptibility to pancreatic injury through several mechanisms ranging from trauma to gallstones to viruses.

Pathogenesis of chronic pancreatitis: an evidence-based review of past theories and recent developments

In the past several decades, four prominent theories of chronic pancreatitis pathogenesis have emerged: the toxic-metabolic theory, the oxidative stress hypothesis, the stone and duct obstruction theory, and the necrosis-fibrosis hypothesis. Although these traditional theories are formulated based on compelling scientific observations, substantial contradictory data also exist for each. Furthermore, the basic premises of some of these theories are directly contradictory. Because of the recent scientific progress in the underlying genetic, cellular, and molecular pathophysiology, there have been substantial advances in the understanding of chronic pancreatitis pathogenesis. This paper will provide an evidence-based review and critique of the traditional pathogenic theories, followed by a discussion of the new advances in pancreatic fibrogenesis. Moreover, we will discuss plausible pathogenic sequences applied to each of the known etiologies.

Reg gene family and human diseases

Regenerating gene (Reg or REG) family, within the superfamily of C-type lectin, is mainly involved in the liver, pancreatic, gastric and intestinal cell proliferation or differentiation. Considerable attention has focused on Reg family and its structurally related molecules. Over the last 15 years, 17 members of the Reg family have been cloned and sequenced. They have been considered as members of a conserved protein family sharing structural and some functional properties being involved in injury, inflammation, diabetes and carcinogenesis. We previously identified Reg IV as a strong candidate for a gene that was highly expressed in colorectal adenoma when compared to normal mucosa based on suppression subtractive hybridization (SSH), reverse Northern blot, semi-quantitative reverse transcriptase PCR (RT-PCR) and Northern blot. In situ hybridization results further support that overexpression of Reg IV may be an early event in colorectal carcinogenesis. We suggest that detection of Reg IV overexpression might be useful in the early diagnosis of carcinomatous transformation of adenoma. This review summarizes the roles of Reg family in diseases in the literature as well as our recent results of Reg IV in colorectal cancer. The biological properties of Reg family and its possible roles in human diseases are discussed. We particularly focus on the roles of Reg family as sensitive reactants of tissue injury, prognostic indicators of tumor survival and early biomarkers of carcinogenesis. In addition to our current understanding of Reg gene functions, we postulate that there might be relationships between Reg family and microsatellite instability, apoptosis and cancer with a poor prognosis. Investigation of the correlation between tumor Reg expression and survival rate, and analysis of the Reg gene status in human maliganancies, are required to elucidate the biologic consequences of Reg gene expression, the implications for Reg gene regulation of cell growth, tumorigenesis, and the progression of cancer. It needs to be further attested whether Reg gene family is applicable in early detection of cancer and whether Reg and Reg-related molecules can offer novel molecular targets for anticancer therapeutics. This has implications with regard to prognosis, such as in monitoring cancer initiation, progression and recurrence, as well as the design of chemotherapeutic drugs.

Xanthine oxidase-derived oxygen radicals play significant roles in the development of chronic pancreatitis in WBN/Kob rats

BACKGROUND

Although oxygen-derived free radicals are known to play a role in cell injury and DNA alterations, the role of active oxidants in chronic pancreatitis has not been fully elucidated. Using WBN/Kob rats, which spontaneously develop chronic pancreatitis-like lesions, we investigated whether xanthine oxidase (XOD)-derived oxygen radicals are involved in pancreatic tissue injury.

METHODS

WBN/Kob rats were fed a control or a tungsten diet. The latter depletes XOD activity. Histologic al changes, glutathione (GSH) content and XOD and superoxide dismutase (SOD) activities were determined in pancreatic tissue. Pancreatic 8-hydroxy-deoxyguanosine (8-OH-dG) levels and lithostathine mRNA were also examined.

RESULTS

In WBN/Kob rats, parenchymal destruction and fibrosis developed at approximately 12 weeks of age and progressed with each month. The activity of XOD was significantly higher in the early period (8-12 weeks), whereas the levels of GSH and SOD decreased after 16 weeks. Levels of 8-OH-dG in WBN/Kob rats were significantly elevated at 16 weeks. Lithostathine mRNA levels started to increase at 8 weeks, but were suppressed at 16 weeks. The tungsten diet significantly attenuated the histological changes in WBN/Kob rats. The increase in pancreatic XOD activity and 8-OH-dG content in WBN/Kob rats was significantly inhibited by the tungsten diet and lithostathine mRNA levels remained high at 16 weeks.

CONCLUSION

These results suggest that oxygen radicals generated by XOD play an important role in oxidative DNA damage and the development of chronic pancreatic injury.

Chronic pancreatitis: diagnosis, classification, and new genetic developments

The utilization of recent advances in molecular and genomic technologies and progress in pancreatic imaging techniques provided remarkable insight into genetic, environmental, immunologic, and pathobiological factors leading to chronic pancreatitis. Translation of these advances into clinical practice demands a reassessment of current approaches to diagnosis, classification, and staging. We conclude that an adequate pancreatic biopsy must be the gold standard against which all diagnostic approaches are judged. Although computed tomography remains the initial test of choice for the diagnosis of chronic pancreatitis, the roles of endoscopic retrograde pancreatography, endoscopic ultrasonography, and magnetic resonance imaging are considered. Once chronic pancreatitis is diagnosed, proper classification becomes important. Major predisposing risk factors to chronic pancreatitis may be categorized as either (1) toxic-metabolic, (2) idiopathic, (3) genetic, (4) autoimmune, (5) recurrent and severe acute pancreatitis, or (6) obstructive (TIGAR-O system). After classification, staging of pancreatic function, injury, and fibrosis becomes the next major concern. Further research is needed to determine the clinical and natural history of chronic pancreatitis developing in the context of various risk factors. New methods are needed for early diagnosis of chronic pancreatitis, and new therapies are needed to determine whether interventions will delay or prevent the progression of the irreversible damage characterizing end-stage chronic pancreatitis.

New insights into hereditary pancreatitis

The recent discovery that mutations in the trypsinogen gene are responsible for acute and chronic pancreatitis, and that patients with hereditary pancreatitis are at great risk for pancreatic cancer, has opened the door to understanding many aspects of pancreatic disease. This review focuses on the clinical presentation of hereditary pancreatitis, the mechanism of disease, and implications of this disease on understanding acute and chronic pancreatitis.