Liaobin Chen

Caffeine-induced activated glucocorticoid metabolism in the hippocampus causes hypothalamic-pituitary-adrenal axis inhibition in fetal rats.

Epidemiological investigations have shown that fetuses with intrauterine growth retardation (IUGR) are susceptible to adult metabolic syndrome. Clinical investigations and experiments have demonstrated that caffeine is a definite inducer of IUGR, as children who ingest caffeine-containing food or drinks are highly susceptible to adult obesity and hypertension. Our goals for this study were to investigate the effect of prenatal caffeine ingestion on the functional development of the fetal hippocampus and the hypothalamic-pituitary-adrenal (HPA) axis and to clarify an intrauterine HPA axis-associated neuroendocrine alteration induced by caffeine. Pregnant Wistar rats were intragastrically administered 20, 60, and 180 mg/kg·d caffeine from gestational days 11–20. The results show that prenatal caffeine ingestion significantly decreased the expression of fetal hypothalamus corticotrophin-releasing hormone. The fetal adrenal cortex changed into slight and the expression of fetal adrenal steroid acute regulatory protein (StAR) and cholesterol side-chain cleavage enzyme (P450scc), as well as the level of fetal adrenal endogenous corticosterone (CORT), were all significantly decreased after caffeine treatment. Moreover, caffeine ingestion significantly increased the levels of maternal and fetal blood CORT and decreased the expression of placental 11β-hydroxysteroid dehydrogenase-2 (11β-HSD-2). Additionally, both in vivo and in vitro studies show that caffeine can downregulate the expression of fetal hippocampal 11β-HSD-2, promote the expression of 11β-hydroxysteroid dehydrogenase 1 and glucocorticoid receptor (GR), and enhance DNA methylation within the hippocampal 11β-HSD-2 promoter. These results suggest that prenatal caffeine ingestion inhibits the development of the fetal HPA axis, which may be associated with the fetal overexposure to maternal glucocorticoid and activated glucocorticoid metabolism in the fetal hippocampus. These results will be beneficial in elucidating the developmental toxicity of caffeine and in exploring the fetal origin of adult HPA axis dysfunction and metabolic syndrome susceptibility for offspring with IUGR induced by caffeine.

Caffeine-induced fetal rat over-exposure to maternal glucocorticoid and histone methylation of liver IGF-1 might cause skeletal growth retardation

Several epidemiological investigations, including previous work by our laboratory, indicate that maternal caffeine consumption is associated with intrauterine growth retardation and impaired fetal length growth. Skeletal development is critical for length growth. In the present study, our goals were to determine the effects of prenatal caffeine exposures on fetal skeletal growth and to investigate the mechanisms associated with such effects. Pregnant Wistar rats were injected intragastrically with 120mg/kg of caffeine intragastrically each day from gestational days 11-20. Maternal prenatal caffeine exposure was associated with decreased fetal femur lengths and inhibited of synthesis of extracellular matrices in fetal growth plates Moreover, caffeine exposure significantly increased the levels of fetal blood corticosterone and decreased IGF-1mRNA expression levels in the liver and growth plate. The expression levels of IGF-1 signaling pathway components (IGF-1R, IRS-1, AKT1/2 and Col2A1) were also reduced. In addition, the results of chromatin immunoprecipitation assays indicated that caffeine exposure down-regulated histone methylation of fetal IGF-1 in the liver. These results suggest that prenatal caffeine exposure may inhibit fetal skeletal growth through a mechanism that is associated with increased fetal exposure to maternal glucocorticoids and results in lower IGF-1 signaling pathway activity. Taken together, these results raise important concerns regarding the skeletal growth toxicity of caffeine and potentially indicate the intrauterine origins of adult osteoporosis and osteoarthritis.

PROTECTION BY AND ANTI-OXIDANT MECHANISM OF BERBERINE AGAINST RAT LIVER FIBROSIS INDUCED BY MULTIPLE HEPATOTOXIC FACTORS

1 The aim of the present study was to investigate the effect and mechanism of berberine, an alkaloid extracted from the traditional Chinese medicine coptis, on rat liver fibrosis induced by multiple hepatotoxic factors. 2 Male Wistar rats were separated into five groups, a normal control group, a fibrotic control group and fibrotic groups treated with three different doses of berberine. The fibrotic models were established by introduction of multiple hepatotoxic factors, including CCl4, ethanol and high cholesterol. Rats in the treatment groups were administered 50, 100 or 200 mg/kg berberine, intragastrically, daily for 4 weeks. Serum levels of alanine aminotransferase (ALT) and serum aspartate aminotransferase (AST), hepatic activity of superoxide dismutase (SOD) and hepatic malondialdehyde (MDA) and hepatic hydroxyproline (Hyp) content were determined. Liver biopsies were obtained for histological and immunohistochemical studies to detect the expressions of a‐smooth muscle actin (SMA) and transforming growth factor (TGF)‐b1. 3 The results showed that, compared with the fibrotic control group, serum levels of ALT and AST and hepatic content of MDA and Hyp were markedly decreased, but the activity of hepatic SOD was significantly increased in berberine‐treated groups in a dose‐dependent manner. In addition, histopathological changes, such as steatosis, necrosis and myofibroblast proliferation, were reduced and the expression of a‐SMA and TGF‐b1 was significantly downregulated in the berberine‐treated groups (P < 0.01). 4 These results suggest that berberine could be used to prevent experimental liver fibrosis through regulation of the anti‐oxidant system and lipid peroxidation.

Effects of adenovirus-mediated bFGF, IL-1Ra and IGF-1 gene transfer on human osteoarthritic chondrocytes and osteoarthritis in rabbits

The study investigated the effects of adenovirus-mediated gene transfection of basic fibroblast growth factor (bFGF), bFGF combined with interleukin-1 receptor antagonist protein (IL-Ra) and/or insulin-like growth factor-1 (IGF-1) both in human osteoarthritis (OA) chondrocytes and rabbits OA model. Human OA chondrocytes were delivered by adenovirus-mediated bFGF, IL-Ra and IGF-1 vectors, respectively. Chondrocyte proliferation, glycosaminoglycan (GAG) content, expression of type II collagen, ADAMTS-5, MMP-13, MMP-3 and TIMP-1 were determined. Rabbit OA model was induced by anterior cruciate ligament transaction (ACLT) in knees. Adenoviral vectors encoding human bFGF, IL-Ra and IGF-1 were injected intraarticularly into the knee joints after ACLT. The effects of adenovirus- mediated gene transfection on rabbit OA were evaluated. In vitro, the transfected genes were expressed in cell supernatant of human OA chondrocytes. AdbFGF group significantly promoted chondrocyte proliferation, and increased GAG and type II collagen synthesis than in the OA group. As two or three genes were transfected in different combinations, there was significant enhancement on the GAG content, type II collagen synthesis, and TIMP-1 levels, while ADAMTS-5, MMP-13, and MMP-3 levels were reduced. In vivo, the transfected genes were expressed in synovial fluid of rabbits. Intraarticular delivery of bFGF enhanced the expression of type II collagen in cartilage and decreased cartilage Mankin score compared with the OA control group (P = 0.047; P < 0.01, respectively). Multiple-gene transfection in different combinations showed better results than bFGF transfection alone. This study suggests that bFGF gene transfection is effective in treating experimental OA. Multiple gene transfection has better biologic effects on OA.

Nicotine-induced over-exposure to maternal glucocorticoid and activated glucocorticoid metabolism causes hypothalamic–pituitary–adrenal axis-associated neuroendocrine metabolic alterations in fetal rats

Fetuses with intrauterine growth retardation (IUGR) induced by prenatal nicotine exposure are susceptible to adult metabolic syndrome. Our goals for this study were to investigate the effects of prenatal nicotine exposure on the fetal hypothalamic-pituitary-adrenal (HPA) axis and glucose and lipid metabolism and to explain the susceptibility to adult metabolic syndrome for fetuses with nicotine induced-IUGR. Pregnant Wistar rats were administered 0.25, 0.5, and 1.0 mg/kg nicotine subcutaneously twice a day from gestational day 11 to 20. Nicotine exposure significantly increased the levels of fetal blood corticosterone and decreased the expression of placental 11β-hydroxysteroid dehydrogenase-2 (11β-HSD-2). Moreover, nicotine exposure significantly increased the expressions of fetal hippocampal 11β-HSD-1 and glucocorticoid receptor (GR) and decreased the expressions of fetal hypothalamus corticotropin-releasing hormone, adrenal steroid acute regulatory protein, and cholesterol side-chain cleavage enzyme. Additionally, increased expressions of 11β-HSD-1 and GR were observed in fetal liver and gastrocnemius muscle, and these tissues also expressed lower levels of insulin-like growth factor-1 (IGF-1), IGF-1 receptor, and insulin receptor, while expressing increased levels of adiponectin receptor, leptin receptors, and AMP-activated protein kinase α2. Prenatal nicotine exposure causes HPA axis-associated neuroendocrine metabolic alterations in fetal rats. The underlying mechanism may involve activated glucocorticoid metabolism in various fetal tissues.

Fetal rat metabonome alteration by prenatal caffeine ingestion probably due to the increased circulatory glucocorticoid level and altered peripheral glucose and lipid metabolic pathways

The aims of this study were to clarify the metabonome alteration in fetal rats after prenatal caffeine ingestion and to explore the underlying mechanism pertaining to the increased fetal circulatory glucocorticoid (GC). Pregnant Wistar rats were daily intragastrically administered with different doses of caffeine (0, 20, 60 and 180 mg/kg) from gestational days (GD) 11 to 20. Metabonome of fetal plasma and amniotic fluid on GD20 were analyzed by ¹H nuclear magnetic resonance-based metabonomics. Gene and protein expressions involved in the GC metabolism, glucose and lipid metabolic pathways in fetal liver and gastrocnemius were measured by real-time RT-PCR and immunohistochemistry. Fetal plasma metabonome were significantly altered by caffeine, which presents as the elevated α- and β-glucose, reduced multiple lipid contents, varied apolipoprotein contents and increased levels of a number of amino acids. The metabonome of amniotic fluids showed a similar change as that in fetal plasma. Furthermore, the expressions of 11β-hydroxysteroid dehydrogenase 2 (11β-HSD-2) were decreased, while the level of blood GC and the expressions of 11β-HSD-1 and glucocorticoid receptor (GR) were increased in fetal liver and gastrocnemius. Meanwhile, the expressions of insulin-like growth factor 1 (IGF-1), IGF-1 receptor and insulin receptor were decreased, while the expressions of adiponectin receptor 2, leptin receptors and AMP-activated protein kinase α2 were increased after caffeine treatment. Prenatal caffeine ingestion characteristically change the fetal metabonome, which is probably attributed to the alterations of glucose and lipid metabolic pathways induced by increased circulatory GC, activated GC metabolism and enhanced GR expression in peripheral metabolic tissues.

A hypothalamic-pituitary-adrenal axis-associated neuroendocrine metabolic programmed alteration in offspring rats of IUGR induced by prenatal caffeine ingestion.

Caffeine is a definite factor of intrauterine growth retardation (IUGR). Previously, we have confirmed that prenatal caffeine ingestion inhibits the development of hypothalamic-pituitary-adrenal (HPA) axis, and alters the glucose and lipid metabolism in IUGR fetal rats. In this study, we aimed to verify a programmed alteration of neuroendocrine metabolism in prenatal caffeine ingested-offspring rats. The results showed that prenatal caffeine (120 mg/kg.day) ingestion caused low body weight and high IUGR rate of pups; the concentrations of blood adrenocorticotropic hormone (ACTH) and corticosterone in caffeine group were significantly increased in the early postnatal period followed by falling in late stage; the level of blood glucose was unchanged, while blood total cholesterol (TCH) and triglyceride (TG) were markedly enhanced in adult. After chronic stress, the concentrations and the gain rates of blood ACTH and corticosterone were obviously increased, meanwhile, the blood glucose increased while the TCH and TG decreased in caffeine group. Further, the hippocampal mineralocorticoid receptor (MR) expression in caffeine group was initially decreased and subsequently increased after birth. After chronic stress, the 11β-hydroxysteroid dehydrogenase-1, glucocorticoid receptor (GR), MR as well as the MR/GR ratio were all significantly decreased. These results suggested that prenatal caffeine ingestion induced the dysfunction of HPA axis and associated neuroendocrine metabolic programmed alteration in IUGR offspring rats, which might be related with the functional injury of hippocampus. These observations provide a valuable experimental basis for explaining the susceptibility of IUGR offspring to metabolic syndrome and associated diseases.

Intrauterine metabolic programming alteration increased susceptibility to non-alcoholic adult fatty liver disease in prenatal caffeine-exposed rat offspring.

An increase in susceptibility to metabolic syndromes (MetS) in rat offspring that experienced prenatal caffeine exposure (PCE) has been previously demonstrated. The present study aimed to clarify this increased susceptibility and elucidate the mechanism of foetal origin that causes or contributes to adult non-alcoholic fatty liver disease (NAFLD) as a result of PCE. Based on the results from both foetal and adult studies of rats that experienced PCE (120 mg/kgd), the foetal weight and serum triglyceride levels decreased significantly and hepatocellular ultrastructure was altered. Foetal livers exhibited inhibited insulin-like growth factor-1 (IGF-1), enhanced lipogenesis and reduced lipid output. In adult female offspring of PCE+lab chow, lipid synthesis, oxidation and output were enhanced, whereas lipogenesis was inhibited in their male conterparters. Furthermore, in adult offspring of PCE+ high-fat diet, catch-up growth appeared obvious with enhanced hepatic IGF-1, especially in females. Both males and females showed increased lipid synthesis and reduced output, which were accompanied by elevated serum triglyceride. Severe NAFLD appeared with higher Kleiner scores. Gluconeogenesis was continuously enhanced in females. Therefore, increased susceptibility to diet-induced NAFLD in PCE offspring was confirmed, and it appears to be mediated by intrauterine glucose and alterations in lipid metabolic programming. This altered programming enhanced foetal hepatic lipogenesis and reduced lipid output in utero, which continued into the postnatal phase and reappeared in adulthood with the introduction of a high-fat diet, thereby aggravating hepatic lipid accumulation and causing NAFLD.

Response to 'TNF/TNFR signal transduction pathway-mediated anti-apoptosis and anti-inflammatory effects of sodium ferulate on IL-1β-induced rat osteoarthritis chondrocytes in vitro'

Introduction: Sodium ferulate (SF) is a natural component of traditional Chinese herbs. Our previous study shows that SF has a protective effect on osteoarthritis (OA). The objective of this study was to investigate the effect of SF on the TNF/TNF receptor (TNFR) signal transduction pathway of rat OA chondrocytes. Methods: Primary rat articular chondrocytes were co-treated with IL-1b and SF. Chondrocyte apoptosis was assessed by fluorescein isothiocyanate-annexin V/propidium iodide assay. The PCR array was used to screen the expression of 84 key genes involved in apoptosis. The release of TNFa and prostaglandin E2 were analyzed by ELISA. Expressions of proteins were assessed by western blotting. The activity of NFB was determined by electrophoretic mobility shift assay (EMSA). Gene expression of inducible nitric oxide synthase (iNOS) was evaluated by real-time quantitative PCR. The nitric oxide content was measured with the Griess method. Results: After treatment with SF, the apoptosis rate of chondrocytes significantly attenuated (P < 0.01). Results of the apoptosis PCR array suggested that mRNA expression of some core proteins in the TNF/TNFR pathway showed valuable regulation. The protein expressions of TNFa, TNFR-1, TNF receptor-associated death domain, caspase-8 and caspase-3 were prevented by SF in a concentration-dependent manner. SF also inhibited activities of caspase-8 and caspase-3 compared with the OA model control (P < 0.01). TNF receptor-associated factor-2 expression, phosphorylations of inhibitor of NFB kinase (IKK) subunits alpha and beta, and NFB inhibitor, alpha (I Ba) were all concentration-dependently suppressed by SF treatment. The results of EMSA showed that SF inhibited the activity of NFB. In addition, the expressions of cycloxygenase-2 and iNOS and the contents of prostaglandin E2 and NO were attenuated with the treatment of SF (P < 0.01). Conclusion: SF has anti-apoptosis and anti-inflammatory effects on an OA model induced by IL-1b in vitro, which were due to inhibitory actions on the caspase-dependent apoptosis pathway and the IKK/NFB signal transduction pathway of the TNF/TNFR pathway. † Contributed equally Department of Pharmacology, Basic Medical School, Wuhan University, Donghu Road 169, Wuhan 430071, China Department of Orthopaedic Surgery, Zhongnan Hospital, Wuhan University, Donghu Road 169, Wuhan 430071, China Full list of author information is available at the end of the article Qin et al. Arthritis Research & Therapy 2012, 14:R242 http://arthritis-research.com/content/14/6/R242

Prenatal Food Restriction Induces a Hypothalamic-Pituitary-Adrenocortical Axis-associated Neuroendocrine Metabolic Programmed Alteration in Adult Offspring Rats

BACKGROUND AND AIMS Intrauterine growth restriction produces susceptibility to adult metabolic syndrome, which may be caused by the permanent alteration of the hypothalamic-pituitary-adrenocortical (HPA) axis. We aimed to verify that HPA axis-associated neuroendocrine metabolic programming is altered in food-restricted (FR) offspring. METHODS Maternal rats were fed a restricted diet from gestational day 11 until full-term delivery, all pups were fed a high-fat diet after weaning and exposed to unpredictable chronic stress (UCS) during postnatal weeks 17-20. RESULTS Serum levels of adrenocorticotrophic hormone and corticosterone in adult offspring of the prenatal FR group were lower than the control (CN) rats before UCS but increased significantly after UCS. Serum glucose levels in the FR group were normal before UCS but increased after UCS. Serum insulin levels were significantly decreased in FR males but showed a slight increase in FR females before UCS; however, insulin levels decreased significantly in the FR male and female rats after UCS. Before UCS, serum lipid levels were higher in the FR males but were normal in the FR females; after UCS, FR males had a slight decrease and FR females had an increasing trend in serum lipids levels. Lipid droplets in the hypothalamus, pituitary gland, and livers of the FR group indicated steatosis. CONCLUSIONS These results suggest that prenatal food restriction alters HPA axis-associated neuroendocrine metabolism in adult offspring fed a high-fat diet, which may originate from the intrauterine programming and increase the susceptibility to adult metabolic diseases.