Dexamethasone restores transforming growth factor-ß activated kinase 1 expression and phagocytosis activity of Kupffer cells in cholestatic liver injury.

The role of transforming growth factor-ß activated kinase 1 (TAK1) in modulating the function of Kupffer cells (KCs) within cholestatic livers remains unclear. This study examined the immunopharmacological action of dexamethasone (DEX) in modulating hepatic TAK1 expression and related signaling activity in a rat model of bile duct ligation-mimicked obstructive jaundice. The in vitro effects of DEX on porcine biliary extract (PBE)-modulated gene expression and phagocytosis of KCs were examined using a rat alveolar macrophage cell line (NR8383 cells). Although DEX therapy did not restore the downregulated TAK1 expression and phosphorylation, it significantly attenuated the upregulation of high-mobility group box 1 expression and caspase-3 activation in whole liver extracts of cholestatic rats, possibly via enhancing extracellular signal-regulated kinase-mediated signaling. Dual immunofluorescence staining of cholestatic livers and western detection on primary KCs isolated from cholestatic livers identified that DEX treatment indeed increased both the expression and phosphorylation levels of TAK1 in the KCs of cholestatic livers. In vitro studies using alveolar NR8383 macrophages with KC-characteristic gene expression further demonstrated that DEX not only repressed the pro-inflammatory cytokine production including with respect to interleukin (IL)-1ß and IL-6, but also enhanced gene expression of TAK1 and a phagocytic marker, natural-resistance-associated macrophage protein 1, under PBE-mimicked cholestatic conditions. However, WST-1 assay showed that DEX did not protect NR8383 macrophages against the PBE-induced cytotoxicity. Immunofluorescence visualization of cellular F-actin by phalloidin suggested that DEX sustained the PBE-induced phagocytosis morphology of NR8383 macrophages. In conclusion, DEX treatment may pharmacologically restore the expression and activity of TAK1 in KCs, and sustain the phagocytic phenotype of KCs in cholestatic livers.

Postnatal high-fat diet leads to spatial deficit, obesity, and central and peripheral inflammation in prenatal dexamethasone adult offspring rats.

Synthetic glucocorticoids are frequently used in clinical practice for treating pregnant women at risk of preterm delivery, but their long-term effects on the infant brain are largely unknown. Pregnant Sprague-Dawley rats were administered vehicle or dexamethasone between gestational days 14 and 21. Male offspring were then weaned onto either a standard chow or a high-fat diet. The postnatal levels of insulin-like growth factor I (IGF-1), tumor necrosis factor-α (TNF-α), and asymmetric dimethylarginine (ADMA) in the plasma, liver, and brain were examined, as well as the possible effects of prenatal dexamethasone on cognition. We found that a postnatal high-fat diet led to spatial deficits detected by the Morris water maze in adult offspring administered dexamethasone prenatally. The spatial deficit was accompanied by decreased IGF-1 mRNA and increased ADMA levels in the dorsal hippocampus. In peripheral systems, a postnatal high-fat diet resulted in decreased plasma IGF-1, increased plasma corticosterone, increased concentrations of transaminases, TNF-α mRNA, and ADMA in the liver, and associated obesity in adult offspring administered prenatal dexamethasone. In conclusion, a postnatal high-fat diet led to spatial deficits, obesity, and altered levels of IGF-1, TNF-α, and ADMA in the plasma, liver, or brain.

Programming Effects of Prenatal Glucocorticoid Exposure with a Postnatal High-Fat Diet in Diabetes Mellitus.

Increasing evidence has shown that many chronic diseases originate from early life, even before birth, through what are termed as fetal programming effects. Glucocorticoids are frequently used prenatally to accelerate the maturation of the lungs of premature infants. High-fat diets are associated with insulin resistance, but the effects of prenatal glucocorticoid exposure plus a postnatal high-fat diet in diabetes mellitus remain unclear. We administered pregnant Sprague-Dawley rats' intraperitoneal dexamethasone (0.1 mg/kg body weight) or vehicle at gestational days 14-20. Male offspring were administered a normal or high-fat diet starting from weaning. We assessed the effects of prenatal steroid exposure plus postnatal high-fat diet on the liver, pancreas, muscle and fat at postnatal day 120. At 15 and 30 min, sugar levels were higher in the dexamethasone plus high-fat diet (DHF) group than the vehicle plus high-fat diet (VHF) group in the intraperitoneal glucose tolerance test (IPGTT). Serum insulin levels at 15, 30 and 60 min were significantly higher in the VHF group than in the vehicle and normal diet group. Liver insulin receptor and adenosine monophosphate-activated protein kinase mRNA expressions and protein levels were lower in the DHF group. Insulin receptor and insulin receptor substrate-1 mRNA expressions were lower in the epididymal adipose tissue in the VHF and DHF groups. "Programming" of liver or epididymal adipose tissue resulted from prenatal events. Prenatal steroid exposure worsened insulin resistance in animals fed a high-fat diet.

Sex differences of oxidative stress to cholestatic liver and kidney injury in young rats.

BACKGROUND: Sexual dimorphism plays a role in the liver and in renal injuries. However, whether sex is a risk factor in bile duct ligation (BDL) in young rats has never been examined. METHODS: Six male and six female rats treated with BDL were sacrificed 2 weeks after surgery and were designated as BDL-M and BDL-F groups. The other six male and six female rats that received sham ligation were designated as sham-M and sham-F groups. Plasma biochemistry and liver and kidney asymmetric dimethylarginine (ADMA)-related molecules were examined. RESULTS: Both BDL-M and BDL-F groups had elevated plasma aspartate transaminase (AST), alanine transaminase (ALT), bilirubin, and transforming growth factor-ß1 levels. The BDL-F group had lower plasma AST and ALT levels than the BDL-M group. The BDL-M and BDL-F groups had elevated plasma ADMA levels. The cationic amino acid transporter 1 (CAT1) level was increased in the BDL-F group as compared to the sham-F group, whereas the CAT2 level was reduced in the both BDL-M and BDL-F groups. CONCLUSION: We found that young male rats were prone to higher degrees of biochemical liver and kidney injury to cholestasis. Sex differences in modulation of oxidative stress markers, such as ADMA, may play a role. Our results support careful monitoring and optimal treatment of cholestatic disease, especially in young male patients.

Fish omega-3 fatty acids induce liver fibrosis in the treatment of bile duct-ligated rats.

BACKGROUND: Biliary atresia-induced cholestasis increases hepatic oxidative stress with eventual progression to cirrhosis and liver failure. Omega-3 fatty acids play a possible role in the regulation of oxidative stress and the improvement of cholestasis. AIM: The goal of the present study is to investigate the role of dietary supplementation of fish omega-3 fatty acids in the reduction of hepatocellular damage by using a rat common bile duct ligation model. METHODS: Sprague-Dawley rats received either sham or bile duct ligation (BDL) and were divided into four study groups: Sham+saline (Sham+sal) group, Sham+Fish oil (Sham+FO) group, BDL+saline (BDL+sal) group, and BDL+Fish oil (BDL+FO) group. Rats from each group were assigned to receive, besides regular chow, once daily with either normal saline or fish omega-3 fatty acids (0.4 % of its own body weight) via gavage for 10 days. Samples of blood, liver tissue homogenates, and histological studies from different groups were analyzed at the end of the study. RESULTS: Rats from BDL+FO had significantly impaired liver function as compared to other study groups (p < 0.05 is of significant difference). Ishak scores and the TGF-b1 contents were significantly higher in rats that received BDL+FO, p < 0.05. Contrary to TGF-b1 liver content, rats from the BDL+FO group had the lowest glutathione levels among the study groups, p < 0.05. CONCLUSIONS: Fish omega-3 fatty acids supplementation, albeit increased tissue content of DHA, tended to increase liver fibrosis in BDL rats, decrease liver glutathione level, and compromise hepatic function; fish oil supplementation to subjects with biliary atresia might be of potential hazard and should be used with caution.

Roles of nitric oxide and asymmetric dimethylarginine in pregnancy and fetal programming.

Nitric oxide (NO) regulates placental blood flow and actively participates in trophoblast invasion and placental development. Asymmetric dimethylarginine (ADMA) can inhibit NO synthase, which generates NO. ADMA has been associated with uterine artery flow disturbances such as preeclampsia. Substantial experimental evidence has reliably supported the hypothesis that an adverse in utero environment plays a role in postnatal physiological and pathophysiological programming. Growing evidence suggests that the placental nitrergic system is involved in epigenetic fetal programming. In this review, we discuss the roles of NO and ADMA in normal and compromised pregnancies as well as the link between placental insufficiency and epigenetic fetal programming.

Reappraise the effect of redo-Kasai for recurrent jaundice following Kasai operation for biliary atresia in the era of liver transplantation.

PURPOSE: This study was conducted to reappraise the efficacy of redo-Kasai (or revision) in the era of liver transplantation as a treatment option in those patients with recurrent jaundice after initially successful Kasai procedure. METHODS: We studied ten patients that received redo-Kasai, among a total of 102 patients diagnosed with biliary atresia after receiving Kasai operation from 1986 to 2011. RESULTS: Kasai operation was done at a median age of 55 days and redo-Kasai at 150 days. The bilirubin levels returned to normal in six patients after the procedure. Four of six enjoyed jaundice-free survival with native liver till the time of last follow-up. Three patients died and three received liver transplantation (LT). Only one out of seven patients with three or more episodes of cholangitis survived with native liver, while all the three patients with 1 or 0 episode survived with native liver. The difference was significant (P = 0.033). Re-do Kasai did not result in more blood loss or operative time during LT. CONCLUSION: Redo-Kasai is still valuable in the era of LT and the episodes of cholangitis are the decisive factors affecting the outcome of the procedure.

Selective activation of Toll-like receptor 7 in activated hepatic stellate cells may modulate their profibrogenic phenotype.

Cholestatic liver injury may activate HSCs (hepatic stellate cells) to a profibrogenic phenotype, contributing to liver fibrogenesis. We have previously demonstrated the involvement of TLR (Toll-like receptor) 7 in the pathogenesis of biliary atresia. In the present study we investigated the ability of TLR7 to modulate the profibrogenic phenotype in HSCs. Obstructive jaundice was associated with significant down-regulation of TLR7. Primary HSCs isolated from BDL (bile duct ligation) rats with obstructive jaundice exhibited reduced expression of TLR7 and increased expression of α-SMA (α-smooth muscle actin) and collagen-α1 compared with sham rats, reflecting HSC-mediated changes. Treatment of primary activated rat HSCs and rat T6 cells with CL075, a TLR7 and TLR8 ligand, significantly decreased expression of MCP-1 (monocyte chemotactic protein-1), TGF-ß1 (transforming growth factor-ß1), collagen-α1 and MMP-2 (matrix metalloproteinase-2), and inhibited cell proliferation and migration. In contrast, silencing TLR7 expression with shRNA (short hairpin RNA) in T6 cells effectively blocked the effects of CL075 stimulation, reversing the changes in MCP-1, TGF-ß1 and collagen-α1 expression and accelerating cell migration. Our results indicate that obstructive jaundice is associated with down-regulation of TLR7 and up-regulation of profibrogenic gene expression in HSCs. Selective activation of TLR7 may modulate the profibrogenic phenotype in activated HSCs associated with cholestatic liver injury.

Alterations in NADPH oxidase expression and blood-brain barrier in bile duct ligation-treated young rats: effects of melatonin.

Bile duct ligation (BDL)-treated rats exhibit cholestasis and increased systemic and brain oxidative stress. Activation of NADPH (nicotinamide adenine dinucleotide phosphate) oxidase and disruption of the blood-brain barrier (BBB) are implicated as the pathogenetic mechanisms of brain dysfunction in BDL-treated adult rats. Young rats underwent sham ligation or BDL at day 17 for 2 or 4weeks. Treatment group rats were administered melatonin between day 17 and 45. We found a progressive increase in prefrontal cortex NADPH-dependent superoxide anion (O(2)(-)) production and increased expression of NADPH oxidase subunits in either the prefrontal cortex or the hippocampus in BDL-treated young rats. In addition, expression of intercellular adhesion molecule-1 (ICAM) and tissue plasminogen activator (t-PA) genes were increased in either the prefrontal cortex or the hippocampus. Prefrontal cortex capillary junctional complex proteins expressions including occludin, claudin-5, platelet endothelial cell adhesion molecule-1 and vascular endothelial cadherin were not altered. Melatonin lowered the prefrontal cortex NADPH-dependent O(2)(-) production and t-PA gene expression. We conclude that alterations in NADPH oxidase expression and BBB are involved in brain dysfunction in BDL-treated young rats. In addition, melatonin regulates NADPH oxidase activity and t-PA gene expression.

Effects of hepatocyte CD14 upregulation during cholestasis on endotoxin sensitivity.

Cholestasis is frequently related to endotoxemia and inflammatory response. Our previous investigation revealed a significant increase in plasma endotoxin and CD14 levels during biliary atresia. We therefore propose that lipopolysacharides (LPS) may stimulate CD14 production in liver cells and promote the removal of endotoxins. The aims of this study are to test the hypothesis that CD14 is upregulated by LPS and investigate the pathophysiological role of CD14 production during cholestasis. Using Western blotting, qRT-PCR, and promoter activity assay, we demonstrated that LPS was associated with a significant increase in CD14 and MD2 protein and mRNA expression and CD14 promoter activity in C9 rat hepatocytes but not in the HSC-T6 hepatic stellate cell line in vitro. To correlate CD14 expression and endotoxin sensitivity, in vivo biliary LPS administration was performed on rats two weeks after they were subjected to bile duct ligation (BDL) or a sham operation. CD14 expression and endotoxin levels were found to significantly increase after LPS administration in BDL rats. These returned to basal levels after 24 h. In contrast, although endotoxin levels were increased in sham-operated rats given LPS, no increase in CD14 expression was observed. However, mortality within 24 h was more frequent in the BDL animals than in the sham-operated group. In conclusion, cholestasis and LPS stimulation were here found to upregulate hepatic CD14 expression, which may have led to increased endotoxin sensitivity and host proinflammatory reactions, causing organ failure and death in BDL rats.

Endotoxemia exacerbates kidney injury and increases asymmetric dimethylarginine in young bile duct-ligated rats.

Cirrhosis increases the risk of kidney injury and sepsis, leading to increased mortality. Elevated levels of plasma asymmetric dimethylarginine (ADMA) occur in patients critically ill with cirrhosis, renal failure, and sepsis. We used a rat model of cirrhosis with superimposed sepsis to assess the relationship of plasma and tissue ADMA profiles with acute kidney injury and survival. Seventeen-day-old male Sprague-Dawley rats (n = 37) were randomly assigned to four groups: (1) sham operation plus diet control (n = 6); (2) bile duct ligation (BDL, n = 8); (3) sham operation plus lipopolysaccharide (LPS, n = 9); and (4) BDL plus LPS (n = 14). Lipopolysaccharide was given by intraperitoneal injection (1 mg/kg in saline) 3 h before sacrifice. All rats were sacrificed 14 days after surgery. Lipopolysaccharide increased the rate of BDL-associated death and dysfunction of the liver and kidneys. These results were supported by increased levels of plasma ADMA and a decreased L-arginine/ADMA ratio (AAR). Plasma and tissue levels of ADMA and AAR were not correlated. Lipopolysaccharide restored BDL-induced ADMA level elevation in the liver but increased ADMA level in the kidneys. Lipopolysaccharide increased hepatic AAR, decreased renal AAR, and paradoxically mediated the expression of neuronal nitric oxide synthase-ß in the liver and kidneys. A novel mechanism underlies the LPS-mediated L-arginine-ADMA-nitric oxide pathway activation and exacerbation of kidney injury and mortality in our BDL model. In the presence of cirrhosis with superimposed sepsis, simultaneous lowering of ADMA levels and enhancement of L-arginine levels to restore plasma and renal AARs may be an optimal strategy for the treatment of kidney injury.

Pediatric malignant ovarian tumors: 15 years of experience at a single institution.

BACKGROUND: Malignant ovarian tumors in children are relatively rare. We reviewed our 15-year experience to understand their clinical presentations, managements, and prognoses. METHODS: There were 15 children who were diagnosed to have malignant ovarian tumors from January 1994 to June 2009 in our hospital. The presenting symptoms, treatments, and outcomes were obtained retrospectively from the medical records. RESULTS: The median age at presentation was 13 years. The most common presenting symptom was abdominal pain, occurring in 10 patients (66.7%). The tumors were in the left side in 10 patients (66.7%). The pathologic diagnoses were yolk sac tumors in four patients, immature teratomas in four, dysgerminomas in three, malignant mixed germ cell tumors in three, and carcinosarcoma in one patient. According to the Federation Internationale de Gynecologie Oncologique classification, seven girls had Stage I, one had Stage II, and seven had Stage III disease. Thirteen patients received chemotherapy with platinum-based regimens. Three patients died of their disease: one of yolk sac tumor, one of malignant mixed germ cell tumor, and one of carcinosarcoma. They all had Stage III disease at diagnosis. The 10-year overall survival and disease-free survival rates were 77% and 69%, respectively. CONCLUSIONS: Pediatric malignant ovarian tumors were highly curable disease if they were not in the advanced stage at presentation. Earlier consideration of malignant ovarian tumor in the differential diagnosis of young girls with abdominal pain is important.

Epidemiological features of infantile hypertrophic pyloric stenosis in Taiwanese children: a Nation-Wide Analysis of Cases during 1997-2007.

OBJECTIVE: To describe the epidemiological characteristics of infantile hypertrophic pyloric stenosis (IHPS) in ethnic Chinese children. MATERIALS AND METHODS: We reviewed the National Health Insurance claims database and analyzed data from children less than one year of age who had been diagnosed with IHPS (ICD-9-CM 750.5) and had undergone pyloromyotomy (ICD-9-CM 43.3). We analyzed the incidence, gender, age at diagnosis, length of hospital stay, seasonal variation and cost of IHPS from data collected between January 1997 and December 2007. RESULTS: A total of 1,077 infants met inclusion criteria, including 889 boys and 188 girls. The annual incidence of IHPS ranged from 0.30 to 0.47 per 1,000 live births with a mean incidence of 0.39 per 1,000 live births. Between 2002 and 2007, the incidence showed a declining trend (P = 0.025) with coincidentally increasing trends for both exclusive breastfeeding (P = 0.014) and breastfeeding plus bottle feeding (P = 0.004). The male-to-female rate ratio was dynamic and increased from 3.03 during the first two weeks of life to 8.94 during the 8(th) through 10th weeks of life. The overall male-to-female rate ratio was 4.30. The mean age at diagnosis was 43.1 ± 2.4 days. After analyzing the months of birth and hospital admission, no seasonal variation associated with IHPS was detected. The mean length of hospital stay was 8.28 ± 7.10 days. CONCLUSIONS: The incidence of IHPS in Taiwan, a country with a majority ethnic Chinese population, was lower than observed incidences in Caucasian populations living in Western countries. Breastfeeding campaigns and low maternal smoking rates may contribute to the lower incidence of IHPS in Taiwan. However, additional studies with longer follow-up periods are needed.

Transumbilical laparoscopic appendectomy for acute appendicitis: a reliable one-port procedure.

BACKGROUND: Emergency surgical procedures frequently must be performed at times when availability of adequately trained personnel is problematic yet the requirements for maintaining surgical quality and patient safety remain unchanged. This report aims to describe a safe, effective, transumbilical, one-port laparoscopic technique for appendectomy that can be performed by one surgeon. METHODS: Between January 2006 and December 2008, transumbilical one-port laparoscopic appendectomy (TOPLA) was used by two pediatric surgeons in the authors' department to treat 152 consecutive patients presenting with simple and complicated appendicitis. With the patient placed in the Trendelenburg position and rotated to the left, a single surgeon was easily able to perform the procedure using a 10-mm 0° operative laparoscope (Karl Storz) with a 5-mm working channel. The appendix was lifted with transabdominal suspensory sutures to facilitate its removal. The results were compared with those for 112 patients receiving open appendectomy (OA) during the same period. RESULTS: The operative time was significantly shortened using TOPLA (mean, 61.5 min) compared with using OA (mean, 118.3 min) (p = 0.000). Despite significantly higher numbers of patients with complicated appendicitis enrolled in the TOPLA arm of the study, the rate of wound infection was significantly lower after TOPLA (0%, 0/152) than after OA (9.8%, 11/112) (p = 0.000). The number of patients requesting intramuscular or intravenous analgesics for pain relief was significantly lower after TOPLA than after OA. The overall results for TOPLA were comparable with those for the more common three-port laparoscopic procedure, but it offers the alternative of having an inconspicuous scar hidden within the umbilicus. CONCLUSION: This report describes a simple and safe laparoscopic procedure that offers an effective way for one surgeon to treat simple and complicated appendicitis through a single port with satisfactory cosmetic outcomes.

Carbon dioxide pneumoperitoneum induces anti-inflammatory response and hepatic oxidative stress in young rats with bacterial peritonitis.

PURPOSE: The aim of this study was to investigate the effects of carbon dioxide (CO(2)) pneumoperitoneum on the intra-abdominal spread of bacteria, the local and systemic cytokine expression, and oxidant/antioxidant status in young rats with bacterial peritonitis. METHODS: Young Sprague-Dawley rats, aging 20-27 days and weighing around 50 g, were allocated to six groups of six to nine animals in each. Intra-abdominal infection model was developed by intraperitoneal injection with 1 cc of Escherichia coli (E. coli) (10(8) CFU/mL, ATCC25922 strain) via right lower abdominal wall. Carbon dioxide (CO(2)) pneumoperitoneum was applied to the rats via umbilical pit insufflation with 20 cc CO(2) for 30 min. All survived rats underwent laparotomy and were killed 24 h or 3 days later. Serum levels of CO(2) and CRP were measured. Left lower abdomen peritoneum, peritoneal fluid, mesenteric lymph node of terminal ileum, and liver were taken for bacterial culture. Liver and plasma levels of TNF-α, IL-1ß, and IL-6 were examined for the level of local and systemic immunologic response. Oxidant/antioxidant status in liver and plasma were assessed by measuring malondialdehyde (MDA), and reduced to oxidized glutathione ratio (GSH/GSSG). RESULTS: Carbon dioxide (CO(2)) pneumoperitoneum does not facilitate E. coli dissemination to other intra-abdominal organs in rats with localized E. coli peritonitis. Peritonitis rats that underwent abdominal CO(2) insufflation have insignificantly higher CRP or lower CO(2) levels. Plasma and liver TNF-α, IL-1ß concentrations were not significantly different among the four groups, but plasma IL-6 was significantly increased in rats with E. coli peritonitis and CO(2) pneumoperitoneum that were killed 3 days later as compared with that of rats that were killed 24 h later. In rats with E. coli peritonitis, CO(2) pneumoperitoneum was significantly associated with decreased hepatic GSH/GSSG ratio. However, plasma and liver MDA levels were not altered after CO(2) pneumoperitoneum. CONCLUSIONS: Carbon dioxide (CO(2)) pneumoperitoneum is not associated with E. coli dissemination in the presence of local intra-abdominal infection. CO(2) pneumoperitoneum elicited systemic anti-inflammatory response at a specific time period and decreased hepatic antioxidant status in young rats with E. coli peritonitis.

Bile duct ligation in developing rats: temporal progression of liver, kidney, and brain damage.

PURPOSE: Cholestatic liver disease may result in progressive end-stage liver disease and other extrahepatic complications. We explored the temporal progression of bile duct ligation (BDL)-induced cholestasis in developing rats, focusing on brain cognition and liver and kidney pathology, to elucidate whether these findings were associated with asymmetric dimethylarginine and oxidative stress alterations. MATERIALS AND METHODS: Three groups of young male Sprague-Dawley rats were studied: one group underwent laparotomy (sham), another group underwent laparotomy and BDL for 2 weeks (BDL2), and a third group underwent laparotomy and BDL for 4 weeks (BDL4). RESULTS: The effect of BDL on liver was represented by transforming growth factor beta1 levels and histology activity index scores, which were worse in the BDL4 rats than in the BDL2 rats. BDL4 rats also exhibited more severe spatial memory deficits than BDL2 rats. In addition, renal injury was more progressive in BDL4 rats than in BDL2 rats because BDL4 rats displayed higher Cr levels, elevated tubulointerstitial injury scores, neutrophil gelatinase-associated lipocalin, and symmetric dimethylarginine levels. CONCLUSIONS: Our findings highlight the fact that young BDL rats exhibit similar trends of progression of liver, kidney, and brain damage. Further studies are needed to better delineate the nature of progression of organ damage in young cholestatic rats.

Melatonin blocks oxidative stress-induced increased asymmetric dimethylarginine.

Asymmetric dimethylarginine (ADMA) is a competitive inhibitor of nitric oxide synthase, and its increase is associated with many systemic diseases. We recently found that increases in plasma and hepatic ADMA levels were associated with oxidative stress in young bile-duct-ligation (BDL) rats; these increases were prevented by melatonin therapy. Therefore, we used an in vivo BDL model and in vitro cultured hepatocytes to elucidate the protective mechanisms of melatonin against oxidative stress-induced increase in ADMA. We found that the presence of reactive oxygen species (ROS) in young rats with BDL leads to downregulation of dimethylarginine dimethyaminohydrolase (DDAH)-1 and -2 as well as DDAH activity. Melatonin prevented ADMA increases in the liver mainly by regulating DDAH-1 and -2. The expression and activity of DDAH were suppressed in vitro by superoxide and hydrogen peroxide (H(2)O(2)) in a time-dependent manner, whereas melatonin could block H(2)O(2)-induced downregulation of DDAH-2 as well as decreased DDAH activity, thereby preventing increases in hepatic ADMA. Our findings reveal a mechanistic basis of DDAH downregulation by ROS and suggest that melatonin might be a potential therapy for various diseases with elevated cellular ADMA.

Effects of maternal L-citrulline supplementation on renal function and blood pressure in offspring exposed to maternal caloric restriction: the impact of nitric oxide pathway.

Maternal undernutrition can cause reduced nephron number and glomerular hypertrophy, consequently leading to adult kidney disease. We intended to elucidate whether NO deficiency evolves to kidney disease vulnerability in offspring from mothers with caloric restriction diets and whether maternal L-citrulline (L-Cit) supplementation can prevent this. Using a rat model with 50% caloric restriction, four groups of 3-month-old male offspring were sacrificed to determine their renal outcome: control, caloric restriction (CR), control treated with 0.25% L-citrulline solution during the whole period of pregnancy and lactation (Cit), and CR treated in the same way (CR+Cit group). The CR group had low nephron numbers, increased glomerular diameter, and an increased plasma creatinine level compared with the control group. Maternal L-Cit supplementation prevented these effects. The CR+Cit and Cit groups developed hypertension beginning at 4 and 8weeks of age, respectively. Plasma asymmetric and symmetric dimethylarginine (ADMA and SDMA) levels were increased, but L-arginine/ADMA ratios (AAR) were decreased in the CR group vs the control group. This was prevented by maternal L-Cit supplementation. Renal cortical neuronal NOS-alpha (nNOSalpha) protein abundance was significantly decreased in the Cit and CR+Cit groups. Collectively, reduced nephron number, reduced renal nNOSalpha expression, increased ADMA, and decreased AAR contribute to the developmental programming of adult kidney disease and hypertension. Although maternal L-Cit supplementation prevents caloric restriction-induced low nephron number and renal dysfunction, it also induces hypertension.

Melatonin prevents increased asymmetric dimethylarginine in young rats with bile duct ligation.

Identifying and treating kidney injury in cirrhosis is important. Bile duct ligation (BDL) is a commonly used cholestatic liver disease model. We hypothesized that asymmetric dimethylarginine (ADMA) is involved in BDL-induced oxidative stress and kidney injury, which can be prevented by melatonin. We also intended to elucidate whether increased ADMA is due to increased protein arginine methyltransferase-1 (PRMT1, ADMA-synthesizing enzyme) and/or decreased dimethylarginine dimethylaminohydrolase (DDAH, ADMA-metabolizing enzyme). Three groups of young rats were studied, sham (N = 7), untreated BDL rats (N = 9), and melatonin-treated BDL rats (N = 6, BDL + M). Melatonin-treated BDL rats received daily melatonin 1 mg/kg/day via intraperitoneal injection. One-third of the young BDL rats died compared with none in the BDL + M group. All surviving rats were killed 14 days after surgery. BDL rats had higher plasma aspartate aminotransferase, alanine aminotransferase, direct and total bilirubin, and ammonia levels than shams. They also had kidney injury characterized by increased tubulointerstitial injury scores and plasma creatinine and symmetric dimethylarginine levels, which melatonin prevented. Plasma ADMA levels were elevated in BDL rats, combined with increased hepatic PRMT1 and decreased renal DDAH activity. In addition, melatonin increased hepatic DDAH2 expression, increased DDAH activity and concomitantly decreased ADMA contents in both the liver and kidney. In conclusion, melatonin therapy decreased mortality and prevented kidney injury induced by BDL via reduction of ADMA (by increasing DDAH activity) and oxidative stress.

Reduced brain content of arachidonic acid and docosahexaenoic acid is related to the severity of liver fibrosis.

BACKGROUND: Cognitive deficiency noted post-liver transplantation might be a result of consequential metabolic derangement before liver transplantation. Long-chain polyunsaturated fatty acids, especially arachidonic acid (AA) and docosahexaenoic acid (DHA), affect the development of the central nervous system and its absorption is influenced by obstructive jaundice. AIM: To investigate the possible relationship between the brain content of AA and DHA with the severity of obstructive jaundice using a bile duct ligation rat model. METHODS: Sprague-Dawley rats were divided into three groups: Sham (n = 5): rats received sham operation on P17 (17 days after delivery) and were sacrificed on P31; BDL2w (n = 5): rats received bile duct ligation and were sacrificed on P31; BDL4w (n = 7): rats received bile duct ligation and were sacrificed on P45. Liver function test, histopathology, and fatty acid composition of the brain tissues were analyzed. RESULT: The Sham group had significantly lowered total/direct bilirubin level (0.6 + 0.1/0.3 + 0.1 mg/dl) as compared to the BDL2w group (3.8 + 1.5/1.6 + 1.0 mg/dl) and the BDL4w group (4.3 + 0.6/3.3 + 0.5 mg/dl) (P = 0.04 and 0.008, respectively). Liver fibrosis and inflammatory changes of hepatocytes increased from the Sham group, the BDL2w group, to the BDL4w group. The Sham group had significantly higher AA and DHA content. The brain content of AA and DHA correlated negatively to the duration of bile duct ligation, the total/direct bilirubin level, and the degree of liver fibrosis. CONCLUSION: Our results demonstrated that reduced AA and DHA content in the brain of rats which received bile duct ligation is closely related to both the severity of liver fibrosis and the impairment of liver function.