Numerous studies have characterized the antidiabetic effects of adiponectin, yet the precise cellular mechanisms in skeletal muscle, in particular, changes in autophagy, require further clarification. In the current study, we used a high-fat diet (HFD) to induce obesity and insulin resistance in wild-type (WT) or adiponectin knockout (Ad-KO) mice with and without adiponectin replenishment. Temporal analysis of glucose tolerance and insulin sensitivity using hyperinsulinemic-euglycemic clamp and muscle insulin receptor substrate and Akt phosphorylation demonstrated exaggerated and more rapid HFD-induced insulin resistance in skeletal muscle of Ad-KO mice. Superoxide dismutase activity, the reduced glutathione-to-glutathione disulfide ratio, and lipid peroxidation indicated that HFD-induced oxidative stress was corrected by adiponectin. Gene array analysis implicated several antioxidant enzymes, including Gpxs, Prdx, Sod, and Nox4, in mediating this effect. Adiponectin also attenuated palmitate-induced reactive oxygen species production in cultured myotubes and improved insulin-stimulated glucose uptake in primary muscle cells. Increased LC3-II and decreased p62 expression suggested that HFD induced autophagy in muscle of WT mice; however, these changes were not observed in Ad-KO mice. Replenishing adiponectin in Ad-KO mice increased LC3-II and Beclin1 and decreased p62 protein levels, induced <em>fibroblast</em> <em>growth</em> <em>factor</em>-<em>21</em> expression, and corrected HFD-induced decreases in LC3, Beclin1, and ULK1 gene expression. In vitro studies examining changes in phospho-ULK1 (Ser555), LC3-II, and lysosomal enzyme activity confirmed that adiponectin directly induced autophagic flux in cultured muscle cells in an AMPK-dependent manner. We overexpressed an inactive mutant of Atg5 to create an autophagy-deficient cell model, and together with pharmacological inhibition of autophagy, demonstrated reduced insulin sensitivity under these conditions. In summary, adiponectin stimulated skeletal muscle autophagy and antioxidant potential to reduce insulin resistance caused by HFD.

Acetaminophen (APAP) overdose is a leading cause of drug-induced hepatotoxicity and acute liver failure worldwide, but its pathophysiology remains incompletely understood. <em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) is a hepatocyte-secreted hormone with pleiotropic effects on glucose and lipid metabolism. This study aimed to investigate the pathophysiological role of FGF<em>21</em> in APAP-induced hepatotoxicity in mice. In response to APAP overdose, both hepatic expression and circulating levels of FGF<em>21</em> in mice were dramatically increased as early as 3 hours, prior to elevations of the liver injury markers alanine aminotransferase (ALT) and aspartate aminotransferase (AST). APAP overdose-induced liver damage and mortality in FGF<em>21</em> knockout (KO) mice were markedly aggravated, which was accompanied by increased oxidative stress and impaired antioxidant capacities as compared to wild-type (WT) littermates. By contrast, replenishment of recombinant FGF<em>21</em> largely reversed APAP-induced hepatic oxidative stress and liver injury in FGF<em>21</em> KO mice. Mechanistically, FGF<em>21</em> induced hepatic expression of peroxisome proliferator-activated receptor coactivator protein-1α (PGC-1α), thereby increasing the nuclear abundance of nuclear <em>factor</em> erythroid 2-related <em>factor</em> 2 (Nrf2) and subsequent up-regulation of several antioxidant genes. The beneficial effects of recombinant FGF<em>21</em> on up-regulation of Nrf2 and antioxidant genes and alleviation of APAP-induced oxidative stress and liver injury were largely abolished by adenovirus-mediated knockdown of hepatic PGC-1α expression, whereas overexpression of PGC-1α was sufficient to counteract the increased susceptibility of FGF<em>21</em> KO mice to APAP-induced hepatotoxicity.

CONCLUSIONS

The marked elevation of FGF<em>21</em> by APAP overdose may represent a compensatory mechanism to protect against the drug-induced hepatotoxicity, by enhancing PGC-1α/Nrf2-mediated antioxidant capacity in the liver.

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) has beneficial effects of improving the plasma glucose and lipid profiles in diabetic rodents. Here, we investigated carbohydrate response element binding protein (ChREBP) involvement in the regulation of FGF<em>21</em> mRNA expression in liver. Glucose stimulation and adenoviral overexpression of dominant active ChREBP increased FGF<em>21</em> mRNA. Consistently, adenoviral expression of dominant negative Mlx inhibited glucose induction of FGF<em>21</em> mRNA. Furthermore, deletion studies of mouse FGF<em>21</em> gene promoter (-2000 to +65 bp) revealed a glucose responsive region between -74 and -52 bp. These findings suggest that FGF<em>21</em> expression is regulated by ChREBP.

Macrophages are a major source of proinflammatory cytokines such as tumor necrosis <em>factor</em> alpha (TNF-alpha), which are expressed during conditions of inflammation, infection, or injury. We identified an activity secreted by a macrophage tumor cell line that negatively regulates bacterial lipopolysaccharide (LPS)-induced expression of TNF-alpha. This activity, termed TNF-alpha-inhibiting <em>factor</em> (TIF), suppressed the induction of TNF-alpha expression in macrophages, whereas induction of three other proinflammatory cytokines (interleukin-1beta [IL-1beta], IL-6, and monocyte chemoattractant protein 1) was accelerated or enhanced. A similar or identical inhibitory activity was secreted by IC-<em>21</em> macrophages following LPS stimulation. Inhibition of TNF-alpha expression by macrophage conditioned medium was associated with selective induction of the NF-kappaB p50 subunit. Hyperinduction of p50 occurred with delayed kinetics in LPS-stimulated macrophages but not in <em>fibroblasts</em>. Overexpression of p50 blocked LPS-induced transcription from a TNF-alpha promoter reporter construct, showing that this transcription <em>factor</em> is an inhibitor of the TNF-alpha gene. Repression of the TNF-alpha promoter by TIF required a distal region that includes three NF-kappaB binding sites with preferential affinity for p50 homodimers. Thus, the selective repression of the TNF-alpha promoter by TIF may be explained by the specific binding of inhibitory p50 homodimers. We propose that TIF serves as a negative autocrine signal to attenuate TNF-alpha expression in activated macrophages. TIF is distinct from the known TNF-alpha-inhibiting <em>factors</em> IL-4, IL-10, and transforming <em>growth</em> <em>factor</em> beta and may represent a novel cytokine.

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) is a member of the FGF family that reduces glycemia and ameliorates insulin resistance. Adipose tissue is a main target of FGF<em>21</em> action. Obesity is associated with a chronic proinflammatory state. Here, we analyzed the role of proinflammatory signals in the FGF<em>21</em> pathway in adipocytes, evaluating the effects of TNF-α on β-Klotho and FGF receptor-1 expression and FGF<em>21</em> action in adipocytes. We also determined the effects of rosiglitazone on β-Klotho and FGF receptor-1 expression in models of proinflammatory signal induction in vitro and in vivo (high-fat diet-induced obesity). Because c-Jun NH(2)-terminal kinase 1 (JNK1) serves as a sensing juncture for inflammatory status, we also evaluated the involvement of JNK1 in the FGF<em>21</em> pathway. TNF-α repressed β-Klotho expression and impaired FGF<em>21</em> action in adipocytes. Rosiglitazone prevented the reduction in β-Klotho expression elicited by TNF-α. Moreover, β-Klotho levels were reduced in adipose tissue from high-fat diet-induced obese mice, whereas rosiglitazone restored β-Klotho to near-normal levels. β-Klotho expression was increased in white fat from JNK1(-/-) mice. The absence of JNK1 increased the responsiveness of mouse embryonic <em>fibroblast</em>-derived adipocytes and brown adipocytes to FGF<em>21</em>. In conclusion, we show that proinflammatory signaling impairs β-Klotho expression and FGF<em>21</em> responsiveness in adipocytes. We also show that JNK1 activity is involved in modulating FGF<em>21</em> effects in adipocytes. The impairment in the FGF<em>21</em> response machinery in adipocytes and the reduction in FGF<em>21</em> action in response to proinflammatory signals may play important roles in metabolic alterations in obesity and other diseases associated with enhanced inflammation.

Interleukin-6 is a pleiotropic cytokine with a wide range of effects, including induction of B-cell and cytotoxic T-cell differentiation, and induction of acute phase reactant production by hepatocytes. Interleukin-6 also can act as an autocrine <em>growth</em> <em>factor</em> in malignancy. Various cell types produce interleukin-6, including T and B cells, monocytes, <em>fibroblasts</em>, and some solid tumor cells. In previous work we detected the production of substantial amounts of interleukin-6 by human ovarian cancer cells, including the ovarian cancer cell lines CAOV-3, OVCAR-3, and SKOV-3, and several primary ovarian tumor cultures. In this study we retrospectively examined 90 separate serum specimens for interleukin-6 in 36 patients with epithelial ovarian cancer. The mean serum interleukin-6 concentration of those ovarian cancer patients with macroscopic disease (n = 57) was 0.26 +/- 0.04 U/ml (mean +/- SEM). Healthy adult donors have interleukin-6 serum levels of 0.12 +/- 0.03 U/ml. Sixteen of <em>21</em> ovarian cancer patients with macroscopic disease (76%) had elevated (greater than 0.20 U/ml) levels of serum interleukin-6, with levels approaching 1 U/ml in some patients (p less than 0.01). Of those nine patients with bulky tumor (residual greater than 2 cm), eight (89%) had an elevated interleukin-6 level (mean, 0.31 +/- 0.05), while eight of 12 (66%) with minimal residual disease (less than 2 cm) had elevated levels. Only two of 15 (13%) patients who were in clinical remission and who had microscopic disease had elevated values. Of the 36 patients, 22 were CA 125 negative (less than 35 U/ml), and of these, four had elevated interleukin-6 levels. Of the 14 patients with an elevated CA 125 level, 12 (86%) had elevated interleukin-6 levels. In those 16 patients in whom serial levels of interleukin-6 were measured, rising levels were found over a 3 to 4 month interval in nine (56%); this correlated with tumor progression. Furthermore, the subsequent survival of patients was shown to correlate with the level of interleukin-6, such that patients whose levels were elevated greater than 0.20 U/ml interleukin-6 survived a mean of 12.5 months, compared with 27.2 months for patients with normal levels (p less than 0.001). These data support the concept that interleukin-6 may be a useful tumor marker in some patients with epithelial ovarian cancer, as it correlates with the tumor burden, clinical disease status, and survival.

BACKGROUND

Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG) lead to rapid improvement in insulin sensitivity even before weight loss occurs. Adipokines are closely linked to obesity and insulin resistance. To date, it is unclear whether the different anatomic changes of the various bariatric procedures have different effects on hormones of adipocyte origin. In the present prospective, randomized study, we compared the 1-year follow-up results of LRYGB and LSG concerning weight loss, metabolic control, and fasting adipokine levels.

METHODS

Of 23 nondiabetic morbidly obese patients, 12 were randomized to LRYGB and 11 to LSG. The patients were investigated before and 1 week, 3 months, and 12 months after surgery. The fasting levels of glucose, insulin, lipids, and adipokines (leptin, adiponectin, and <em>fibroblast</em> <em>growth</em> <em>factor</em>-<em>21</em>) were analyzed.

RESULTS

The body weight decreased markedly (P <.001) after either procedure (percentage of weight loss 16.4% ± 1.3%, 24.8% ± 1.7%, and 34.5% ± 2.7% after LRYGB and 13.1% ± 1.1%, 20.7% ± 1.5%, and 27.9% ± 2.6% after LSG at 2, 6, and 12 mo, respectively). The Homeostasis Model Assessment Index declined from 8.0 ± 1.5 preoperatively to 2.9 ± .2 at 12 months after LRYGB and from 7.5 ± 1.7 preoperatively to 3.3 ± .3 at 12 months after LSG. The lipid profiles were normalized. The concentrations of circulating leptin levels decreased by almost 50% as early as 1 week postoperatively and continued to decrease until 12 months postoperatively. Adiponectin increased progressively. The <em>fibroblast</em> <em>growth</em> <em>factor</em>-<em>21</em> levels did not change over time. No difference was found between the LRYGB and LSG groups.

CONCLUSIONS

Both procedures led to significant weight loss associated with the resolution of the metabolic syndrome. The serum leptin levels decreased and adiponectin increased with weight loss, paralleled by improved insulin sensitivity.

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) is a potent metabolic regulator, and pharmacological administration elicits glucose and lipid lowering responses in mammals. To delineate if adipose tissue is the predominant organ responsible for anti-diabetic effects of FGF<em>21</em>, we treated mice with reduced body fat (lipodystrophy mice with adipose specific expression of active sterol regulatory element binding protein 1c; Tg) with recombinant murine FGF<em>21</em> (rmuFGF<em>21</em>). Unlike wildtype (WT) mice, Tg mice were refractory to the beneficial effects of rmuFGF<em>21</em> on body weight, adipose mass, plasma insulin and glucose tolerance. To determine if adipose mass was critical for these effects, we transplanted WT white adipose tissue (WAT) into Tg mice and treated the mice with rmuFGF<em>21</em>. After transplantation, FGF<em>21</em> responsiveness was completely restored in WAT transplanted Tg mice compared to sham Tg mice. Further, leptin treatment alone was sufficient to restore the anti-diabetic effects of rmuFGF<em>21</em> in Tg mice. Molecular analyses of Tg mice revealed normal adipose expression of Fgfr1, Klb and an 8-fold over-expression of Fgf<em>21</em>. Impaired FGF<em>21</em>-induced signaling indicated that residual adipose tissue of Tg mice was resistant to FGF<em>21</em>, whilst normal FGF<em>21</em> signaling was observed in Tg livers. Together these data suggest that adipose tissue is required for the triglyceride and glucose, but not the cholesterol lowering efficacy of FGF<em>21</em>, and that leptin and FGF<em>21</em> exert additive anti-diabetic effects in Tg mice.

MicroRNAs (miRNAs) are a class of noncoding RNA acting at a post-transcriptional level to control the expression of large sets of target mRNAs. While there is evidence that miRNAs deregulation plays a causative role in various complex disorders, their role in fibrotic kidney diseases is largely unexplored. Here, we found a strong up-regulation of miR-<em>21</em> in the kidneys of mice with unilateral ureteral obstruction and also in the kidneys of patients with severe kidney fibrosis. In addition, mouse primary <em>fibroblasts</em> derived from fibrotic kidneys exhibited higher miR-<em>21</em> expression level compared to those derived from normal kidneys. Expression of miR-<em>21</em> in normal primary kidney <em>fibroblasts</em> was induced upon TGFβ exposure, a key <em>growth</em> <em>factor</em> involved in fibrogenesis. Finally, ectopic expression of miR-<em>21</em> in primary kidney <em>fibroblasts</em> was sufficient to promote myofibroblast differentiation. As circulating miRNAs have been suggested as promising non-invasive biomarkers, we further assess whether circulating miR-<em>21</em> levels are associated with renal fibrosis using sera from 42 renal transplant recipients, categorized according to their renal fibrosis severity, evaluated on allograft biopsies (Interstitial Fibrosis/Tubular Atrophy (IF/TA). Circulating miR-<em>21</em> levels are significantly increased in patients with severe IF/TA grade (IF/TA grade 3: 3.0±1.0 vs lower grade of fibrosis: 1.5±1.2; p = 0.001). By contrast, circulating miR-<em>21</em> levels were not correlated with other renal histological lesions. In a multivariate linear regression model including IF/TA grade and estimated GFR, independent associations were found between circulating miR-<em>21</em> levels and IF/TA score (ß = 0.307, p = 0.03), and between miR-<em>21</em> levels and aMDRD (ß = -0.398, p = 0.006). Altogether, these data suggest miR-<em>21</em> has a key pathogenic role in kidney fibrosis and may represent a novel, predictive and reliable blood marker of kidney fibrosis.

Presence of brown adipose tissue (BAT), characterized by the expression of the thermogenic uncoupling protein 1 (UCP1), has recently been described in adult humans. UCP1 is expressed in classical brown adipocytes, as well as in "beige cells" in white adipose tissue (WAT). The thermogenic activity of BAT is mainly controlled by the sympathetic nervous system. Endocrine <em>factors</em>, such as <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) and bone morphogenic protein <em>factor</em>-9 (BMP-9), predominantly produced in the liver, were shown to lead to activation of BAT thermogenesis, as well as to "browning" of WAT. This was also observed in response to irisin, a hormone secreted by skeletal muscles. Different approaches were used to delineate the impact of UCP1 on insulin sensitivity. When studied under thermoneutral conditions, UCP1 knockout mice exhibited markedly increased metabolic efficiency due to impaired thermogenesis. The impact of UCP1 deletion on insulin sensitivity in these mice was not reported. Conversely, several studies in both rodents and humans have shown that BAT activation (by cold exposure, β3-agonist treatment, transplantation and others) improves glucose tolerance and insulin sensitivity. Interestingly, similar results were obtained by adipose tissue-specific overexpression of PR-domain-containing 16 (PRDM16) or BMP4 in mice. The mediators of such beneficial effects seem to include FGF<em>21</em>, interleukin-6, BMP8B and prostaglandin D2 synthase. Interestingly, some of these molecules can be secreted by BAT itself, indicating the occurrence of autocrine effects. Stimulation of BAT activity and/or recruitment of UCP1-positive cells are therefore relevant targets for the treatment of obesity/type 2 diabetes in humans.

OBJECTIVE

<em>Fibroblast</em> <em>growth</em> <em>factor</em> (FGF)-<em>21</em> improves insulin sensitivity and lipid metabolism in obese or diabetic animal models, while human studies revealed increased FGF-<em>21</em> levels in obesity and type 2 diabetes. Given that FGF-<em>21</em> has been suggested to be a peroxisome proliferator-activator receptor (PPAR) alpha-dependent regulator of fasting metabolism, we hypothesized that free fatty acids (FFAs), natural agonists of PPARalpha, might modify FGF-<em>21</em> levels.

METHODS

The effect of fatty acids on FGF-<em>21</em> was investigated in vitro in HepG2 cells. Within a randomized controlled trial, the effects of elevated FFAs were studied in <em>21</em> healthy subjects (13 women and 8 men). Within a clinical trial including 17 individuals, the effect of insulin was analyzed using an hyperinsulinemic-euglycemic clamp and the effect of PPARgamma activation was studied subsequently in a rosiglitazone treatment trial over 8 weeks.

RESULTS

Oleate and linoleate increased FGF-<em>21</em> expression and secretion in a PPARalpha-dependent fashion, as demonstrated by small-interfering RNA-induced PPARalpha knockdown, while palmitate had no effect. In vivo, lipid infusion induced an increase of circulating FGF-<em>21</em> in humans, and a strong correlation between the change in FGF-<em>21</em> levels and the change in FFAs was observed. An artificial hyperinsulinemia, which was induced to delineate the potential interaction between elevated FFAs and hyperinsulinemia, revealed that hyperinsulinemia also increased FGF-<em>21</em> levels in vivo, while rosiglitazone treatment had no effect.

CONCLUSIONS

The results presented here offer a mechanism explaining the induction of the metabolic regulator FGF-<em>21</em> in the fasting situation but also in type 2 diabetes and obesity.

OBJECTIVE

Oxidative stress mediated by reactive oxygen species (ROS) plays a striking role in the pathogenesis of heart failure, and antioxidants have been shown to attenuate cardiac remodelling in experimental models of cardiac damage. We recently showed that <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (Fgf<em>21</em>) is produced by the heart and exerts protective effects, preventing cardiac hypertrophy development. The aim of the study was to determine the effects of Fgf<em>21</em> during oxidative stress signalling in the heart.

RESULTS

Fgf<em>21</em> treatment in cardiomyocytes in culture induced the expression of genes encoding proteins involved in antioxidative pathways, including mitochondrial uncoupling proteins (Ucp2 and Ucp3) and superoxide dismutase-2 (Sod2) and reduced ROS production. In keeping with this, expression of antioxidant genes in response to lipopolysaccharide (LPS)-induced stimulation of pro-inflammatory pathways or isoproterenol-induced cardiac hypertrophy in the heart was reduced in Fgf<em>21</em>-null mice. Moreover, we found that Fgf<em>21</em> is expressed in and released by cardiomyocytes in response to LPS, and its expression is under the control of the Sirt1 (sirtuin-1) pathway. This Fgf<em>21</em> released by cardiomyocytes acts in an autocrine manner to protect cells against oxidative stress. Finally, failing human hearts showed up-regulation of Fgf<em>21</em>, Ucp3, and Sod2, confirming the association between Fgf<em>21</em> induction and the control of cardiac oxidative stress pathways.

CONCLUSIONS

Our data indicate that Fgf<em>21</em> regulates genes involved in antioxidant pathways in an autocrine manner, thus preventing ROS production in cardiac cells. Therefore, Fgf<em>21</em> acts as an antioxidant <em>factor</em> in the heart, preventing induction of pro-oxidative pathways by inflammatory or hypertrophic conditions.

OBJECTIVE

The relationship between parathyroid hormone, fibroblast growth factor 23 (FGF-23), and indices of bone turnover and mineralization in children with early CKD is unknown; thus, this study characterizes the features of renal osteodystrophy and their relationship to biochemical markers of mineral metabolism.

METHODS

Fifty-two patients 2-21 years of age with predialysis CKD underwent tetracycline-labeled bone biopsy. Anthropomorphic measurements and biochemical values were obtained at the time of biopsy.

RESULTS

Serum phosphorus levels were increased in 4% of patients with stage 3 CKD and 43% of those with stage 4/5 CKD. Parathyroid hormone concentrations were elevated in 36% of patients with stage 2, 71% with stage 3, and 93% with stage 4/5 CKD, whereas FGF-23 values were elevated in 81% of all patients, regardless of CKD stage. Bone turnover was normal in all patients with stage 2, but was increased in 13% with stage 3 and 29% with stage 4/5 CKD. Defective mineralization was present in 29% of patients with stage 2, 42% with stage 3, and 79% with stage 4/5 CKD. Defective skeletal mineralization was associated with lower serum calcium levels and increased parathyroid hormone concentrations.

CONCLUSIONS

Elevated circulating FGF-23 levels and defects in skeletal mineralization early in the course of CKD suggest that factors other than the traditional markers of mineral deficiency play a crucial role in the development of renal bone disease.

Progesterone is the hormone of pregnancy and unequivocally required in all mammals for maternal support of conceptus (embryo/fetus and associated membranes) survival and development. The actions of progesterone are mediated by the progesterone receptor (PR). However, the endometrial lumenal (LE) and glandular epithelia (GE) of a number of species exhibit a loss of PR expression prior to the stages of uterine receptivity and implantation. In sheep, PR expression becomes undetectable in the endometrial LE after Day 11 and then in the GE after Day 13. Loss of PR in the GE appears to be required for onset of differentiated functions in terms of production of secretory proteins, such as uterine milk proteins (UTMP) and osteopontin (OPN). Therefore, the actions of progesterone on endometrial epithelia during most of gestation appear to be mediated by the endometrial stroma that remains PR-positive throughout pregnancy. Stromal cells produce several <em>growth</em> <em>factors</em>, such as hepatocyte <em>growth</em> <em>factor</em> (HGF) and <em>fibroblast</em> <em>growth</em> <em>factors</em>-7 and -10 (FGF-7, FGF-10), that have receptors expressed specifically in the endometrial epithelia. These <em>factors</em> may be progesterone-responsive and mediate epithelial-mesenchymal interactions that are crucial for support of pregnancy. Studies of the uterine gland knockout (UGKO) ewe indicate that uterine glands and, by default, their secretions are required for peri-implantation conceptus survival and <em>growth</em>. A complex servomechanism, involving hormones from the ovary and conceptus as well as endogenous betaretroviruses expressed in the endometrial LE and GE, is proposed to regulate endometrial gland differentiation and function during gestation. At estrus, estrogen increases PR expression in the endometrial epithelia. High levels of endogenous Jaagsiekte sheep retroviruses (enJSRVs) are expressed in the PR-positive endometrial LE and GE in response to increasing progesterone and are hypothesized to stimulate trophoblast proliferation and production of interferon (IFN) tau. IFN tau, the pregnancy recognition hormone produced by the trophoblast from Days 10 to <em>21</em>, acts in a paracrine manner on the PR-negative endometrial LE and superficial GE to inhibit transcription of estrogen receptor alpha (ER) and oxytocin receptor (OTR) genes. These actions of IFN tau maintain progesterone production from the corpus luteum by abrogating release of luteolytic pulses of prostaglandin F2 alpha (PGF) from the endometrial epithelium. The antiluteolytic effects of IFN tau are dependent on progesterone. Progesterone stimulation over 8-10 days suppresses expression of the PR gene in the LE and then GE. Loss of the PR in the LE is concomitant with decreases in mucin glycoprotein one (MUC-1), an inhibitor of blastocyst implantation. As the conceptus begins implantation on Day 15, the binucleate trophectodermal cells then differentiate and produce placental lactogen (PL), a member of the prolactin (PRL) and <em>growth</em> hormone (GH) family. PL stimulates GE proliferation and production of secretory proteins, such as UTMP and OPN. Interestingly, the effects of PL on the GE appear to require the absence of PR and prior exposure to IFN tau. During mid-pregnancy, the mononuclear trophectodermal cells produce GH that can also act on a progestinized uterus to stimulate GE hypertrophy and secretory function. The actions of this servomechanism are proposed to stimulate GE hyperplasia from Days 20 to 50 and then GE hypertrophy and maximal differentiated function after Day 50 when the majority of fetal <em>growth</em> and development occurs during gestation.

OBJECTIVE

In transgenic mice overexpressing transforming growth factor (TGF)-alpha in the exocrine pancreas, progressive pancreatic fibrosis and a transdifferentiation of acinar cells to duct-like cells occurs. The present study was undertaken to analyze this transdifferentiation process.

METHODS

Pancreatic specimens were characterized using light microscopy and immunohistochemistry. Expression of the epidermal growth factor receptor (EGFR) and TGF-alpha was evaluated with slot blot and Western analysis. To identify other generic events, K-ras mutations were screened with an enriched polymerase chain reaction approach and p53 expression was detected with immunohistochemistry.

RESULTS

Morphological examination revealed an aggregation of interlobular fibroblasts and a decrease in acinar cell height starting at day 14 after birth. In older animals, these acinar cells change to duct-like cells, which form tubular structures and express ductal markers. Evidence for dysplastic changes was found in 12 of 21 TGF-alpha transgenic mice older than 1 year. We also observed four malignant pancreatic tumors, which were multicentric and originated from dysplastic tubular complexes. They displayed a mixed cystic-papillary phenotype strongly positive for carbonic anhydrase activity. EGFR expression progressively increased in the transition from acinar to duct-like and transformed cells. Activating K-ras mutations could not be detected; however, tubular complexes and tumors displayed increased immunoreactivity for nuclear p53.

CONCLUSIONS

These data suggest an involvement of the TGF-alpha/EGFR pathway in conjunction with other yet unknown events in pancreatic tumor development. Furthermore, these observations are in favor of an acinar-ductal carcinoma sequence. Thus, these transgenic animals will be useful to define genetic alterations associated with a transition from acinar cells to a neoplastic ductal phenotype.

BACKGROUND

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF-<em>21</em>), a potent activator of glucose uptake, has been proposed to be related to insulin resistance, metabolic syndrome (MetS), nonalcoholic fatty liver disease (NAFLD), and weight status.

OBJECTIVE

Our objective was to study the relationships between FGF-<em>21</em>, parameters of MetS, and NAFLD before and after weight loss in obese children.

METHODS

This was a cross-sectional comparison between obese and normal-weight children and longitudinal 1-yr follow-up study in obese children participating in a lifestyle intervention in a primary care setting.

METHODS

Patients included 60 obese and 40 lean children of same age, gender, and pubertal stage.

METHODS

The outpatient 1-yr intervention program was based on exercise, behavior, and nutrition therapy.

METHODS

We evaluated fasting serum FGF-<em>21</em>, weight status [body mass index (BMI) expressed as sd score (SDS)], body fat, insulin resistance index (homeostasis model assessment), leptin, transaminases, free fatty acids (FFA), waist circumference, blood pressure, and lipids.

RESULTS

Compared with the normal-weight children, obese children demonstrated significantly (P < 0.001) increased FGF-<em>21</em>, leptin, and homeostasis model assessment levels. FGF-<em>21</em> was significantly (P < 0.05) correlated to BMI, SDS-BMI, FFA, and leptin both in cross-sectional and longitudinal analyses but not to any additional analyzed parameter. Children with and without MetS or NAFLD did not differ significantly with respect to their FGF-<em>21</em> concentrations. A decrease of SDS-BMI was associated with a significant (P = 0.038) decrease of FGF-<em>21</em> levels (mean -34%).

CONCLUSIONS

FGF-<em>21</em> concentrations are reversibly increased in obese children and are related to leptin and FFA. However, our data do not support a significant relationship between FGF-<em>21</em>, insulin resistance, and features of MetS or NAFLD in children.

Uncontrolled fibrosis in multiple organs is the main cause of death in systemic sclerosis (SSc), and transforming <em>growth</em> <em>factor</em>-β (TGF-β) activation plays a fundamental role in the process. Our previous study demonstrated that miR-<em>21</em> was significantly up-regulated in SSc <em>fibroblasts</em>. Here, we found that TGF-β regulated the expression of miR-<em>21</em> and fibrosis-related genes, and decreased Smad7 expression. Over-expression of miR-<em>21</em> in <em>fibroblasts</em> decreased the levels of Smad7, whereas knockdown of miR-<em>21</em> increased its expression. Further study using a reporter gene assay demonstrated Smad7 was a direct target of miR-<em>21</em>. Similar to human SSc, the expression of miR-<em>21</em> increased in the bleomycin induced skin fibrosis. Inhibition of fibrosis by treatment with anti-fibrosis drug bortezomib restored the levels of miR-<em>21</em> and Smad7. MiR-<em>21</em> may function in an amplifying circuit to enhance TGF-β signaling events in SSc fibrosis, and suggesting that miR-<em>21</em> may act as a potential therapeutic target.

OBJECTIVE

To determine the effects of basic fibroblast growth factor (bFGF) on the chondrocyte anabolic activity promoted by insulin-like growth factor 1 (IGF-1) and osteogenic protein 1 (OP-1).

METHODS

Human articular chondrocytes were cultured in alginate beads or as cartilage explants in serum-free medium with or without IGF-1 (100 ng/ml), OP-1 (100 ng/ml), or bFGF (0-100 ng/ml). Cell survival, proliferation, proteoglycan synthesis, and total proteoglycan accumulation were measured after 21 days of culture in alginate beads, and proteoglycan synthesis was measured in explants.

RESULTS

Cell survival was not altered by bFGF at any dose, and chondrocyte proliferation was stimulated only at doses above 1 ng/ml. When combined with IGF-1, 1 ng/ml of bFGF stimulated proliferation to 170% of control, but when combined with IGF-1 and OP-1, proliferation increased to 373% of control. Doses of bFGF of 100 ng/ml decreased total proteoglycan levels accumulated per cell by 60% compared with control and also inhibited the ability of IGF-1 or OP-1 to increase proteoglycan production. Likewise, sulfate incorporation in response to IGF-1 and OP-1 alone or together was completely inhibited by 50 ng/ml bFGF in both alginate and explant cultures.

CONCLUSIONS

The anabolic activity of IGF-1 and OP-1, alone and in combination, is significantly inhibited by bFGF. The results suggest that excessive release of bFGF from the cartilage matrix during injury, with loading, or in arthritis could contribute to increased proliferation and reduced anabolic activity in articular cartilage.

A lambda cDNA library was prepared from polyadenylated RNA isolated from quiescent human diploid FS-4 <em>fibroblasts</em> stimulated with tumor necrosis <em>factor</em> for 3 h. Differential screening was used to isolate cDNA sequences that are stimulated by tumor necrosis <em>factor</em>. Eight distinct tumor necrosis <em>factor</em>-stimulated gene sequences (designated TSG-1, -6, -8, -12, -14, -<em>21</em>, -27, and -37) were partially sequenced and compared with known sequences from GenBank. TSG-1 was identical to the gene for interleukin-8. TSG-8 corresponded to the gene for monocyte chemotactic and activating <em>factor</em>. TSG-<em>21</em> and -27 were identical to the genes for collagenase and stromelysin, respectively. The other four sequences showed no homologies with known genes. Patterns of induction of mRNAs corresponding to the eight cloned cDNAs by various cytokines, <em>growth</em> <em>factors</em>, and activators of second messenger pathways were analyzed in FS-4 cells.

OBJECTIVE

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) is a hormone with pleiotropic metabolic activities which, in rodents, is robustly regulated by fasting and ketogenic diets. In contrast, similar dietary interventions have either no or minimal effects on circulating FGF<em>21</em> in humans. Moreover, no intervention or dietary challenge has been shown to acutely stimulate circulating FGF<em>21</em> in either humans or animals. Recent animal data suggest that the transcription <em>factor</em> Carbohydrate Responsive-Element Binding Protein (ChREBP) stimulates hepatic FGF<em>21</em> expression and that fructose may activate hepatic ChREBP more robustly than glucose. Here, we examined whether fructose ingestion can acutely stimulate FGF<em>21</em> in humans.

METHODS

We measured serum FGF<em>21</em>, glucose, insulin, and triglyceride levels in ten lean, healthy adults and eleven adults with the metabolic syndrome following oral ingestion of 75 g of glucose, fructose, or a combination of the two sugars.

RESULTS

FGF<em>21</em> levels rose rapidly following fructose ingestion, achieved a mean 3.4-fold increase at two hours (P < 0.01), and returned to baseline levels within five hours. In contrast, FGF<em>21</em> did not increase in the first two hours following ingestion of a glucose load, although more modest increases were observed after three to four hours. Both baseline and fructose-stimulated FGF<em>21</em> levels were 2-3 fold elevated in subjects with metabolic syndrome.

CONCLUSIONS

Fructose ingestion acutely and robustly increases serum FGF<em>21</em> levels in humans in a pattern consistent with a hormonal response. While FGF<em>21</em> appears to be critical for the adaptive response to fasting or starvation in rodents, these findings suggest that in humans, FGF<em>21</em> may play an important role in fructose metabolism.

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) is a hormone induced by various metabolic stresses, including ketogenic and high-carbohydrate diets, that regulates energy homeostasis. In humans, SNPs in and around the FGF<em>21</em> gene have been associated with macronutrient preference, including carbohydrate, fat, and protein intake. Here we show that FGF<em>21</em> administration markedly reduces sweet and alcohol preference in mice and sweet preference in cynomolgus monkeys. In mice, these effects require the FGF<em>21</em> co-receptor β-Klotho in the central nervous system and correlate with reductions in dopamine concentrations in the nucleus accumbens. Since analogs of FGF<em>21</em> are currently undergoing clinical evaluation for the treatment of obesity and type 2 diabetes, our findings raise the possibility that FGF<em>21</em> administration could affect nutrient preference and other reward behaviors in humans.

OBJECTIVE

Intestinal fibrosis and stricture formation are serious complications of Crohn's disease, often requiring surgical intervention. Unfortunately, the mechanisms underlying intestinal fibrosis development are poorly understood, in part because of the lack of relevant animal models. Here, we present a novel murine model of severe and persistent intestinal fibrosis caused by chronic bacterial-induced colitis.

METHODS

Mice were treated with streptomycin 24 hours prior to oral infection with Salmonella enterica serovar Typhimurium. Tissues were analyzed for bacterial colonization and inflammation, and fibrosis was assessed by Masson's trichrome staining and collagen quantification. Expression of the profibrotic cytokines transforming growth factor-beta1, connective tissue growth factor and insulin-like growth factor-I was determined, and the cell types present in fibrotic tissues were assessed by immunohistochemistry.

RESULTS

Infection led to chronic Salmonella colonization of the cecum and colon followed by edema, mucosal ulcerations, and severe transmural inflammation. This pathology was accompanied by significantly elevated expression of transforming growth factor-beta1, connective tissue growth factor, and insulin-like growth factor-I along with extensive type I collagen deposition in the cecal mucosa, submucosa, and muscularis mucosa of infected mice. Fibrosis was evident by 7 days postinfection, peaking at day 21 and still present at day 70. The fibrotic regions were found to be rich in fibroblasts and myofibroblasts.

CONCLUSIONS

These data demonstrate that chronic Salmonella infection of the murine gastrointestinal tract leads to severe tissue fibrosis. Because this model is highly reproducible and easy to perform, it provides great potential for investigating both host and bacterial contributions to intestinal fibrosis.

OBJECTIVE

Serum levels of <em>fibroblast</em> <em>growth</em> <em>factor</em>-<em>21</em> (FGF<em>21</em>), a metabolic hormone, have been shown to be elevated in subjects with adverse lipid profiles, obesity, metabolic syndrome, impaired glucose tolerance, type 2 diabetes mellitus, and hypertension. Recently, elevated serum FGF<em>21</em> levels have also been reported in subjects with coronary heart disease or carotid artery plaques. However, whether serum FGF<em>21</em> is independently associated with atherosclerotic diseases remains unclear. In this study, we examined the relationship between serum FGF<em>21</em> levels and carotid intima-media thickness (IMT) in a large cohort of Southern Chinese subjects.

RESULTS

The cohort consisted of 670 subjects who underwent carotid IMT measurement. Serum FGF<em>21</em> levels were measured with an ELISA kit. Serum FGF<em>21</em> levels positively correlated with carotid IMT in women (r=0.32; P<0.001), but not in men (r=0.06; P=0.305). On multiple linear regression analysis, elevated serum FGF<em>21</em> level in women was an independent risk <em>factor</em> for increased carotid IMT (P=0.039), together with age (P<0.001) and hypertension (P=0.011), in a model comprising also waist circumference, smoking history, serum creatinine, high sensitive C-reactive protein, dysglycemia, and dyslipidemia (adjusted R(2)=35.8%; P<0.001). Elevated serum FGF<em>21</em> levels were also a significant independent risk <em>factor</em> of carotid IMT on multiple stepwise regression analysis (P=0.01).

CONCLUSIONS

The present study is the first demonstration that elevated serum FGF<em>21</em> levels are associated with carotid atherosclerosis in humans, independent of established risk <em>factor</em>s including adverse lipid profiles and C-reactive protein. The role of FGF<em>21</em> as a biomarker or therapeutic target of atherosclerotic diseases warrants further investigation.

<AbstractText>Pegbelfermin (BMS-986036), a PEGylated human <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) analogue, has previously been shown to improve markers of metabolism and liver fibrosis in obese patients with type 2 diabetes. In this phase 2a study, we aimed to evaluate the safety and efficacy of pegbelfermin in patients with non-alcoholic steatohepatitis.</AbstractText><p><div><b>METHODS</b></div>In this multicentre, randomised, double-blind, placebo-controlled, parallel-group, phase 2a study, we recruited adults (aged <em>21</em>-75 years) with a body-mass index of at least 25 kg/m², biopsy-confirmed non-alcoholic steatohepatitis (fibrosis stage 1-3), and a hepatic fat fraction of at least 10% when assessed by magnetic resonance imaging-proton density fat fraction. These patients were enrolled at 17 medical centres in the USA. Eligible patients were stratified by type 2 diabetes status and they were randomly assigned (1:1:1) by a computer-based system to receive subcutaneous injections of placebo once a day, 10 mg pegbelfermin once a day, or 20 mg pegbelfermin once a week, all for 16 weeks. Participants, the study team administering treatment, and investigators analysing outcomes (who were independent of the study team and had no further involvement) were masked to treatment groups. The primary outcomes were safety and the absolute change in hepatic fat fraction after 16 weeks of treatment. All patients who were randomly assigned to groups and received the study drug or placebo were included in the primary analyses. This trial was registered with ClinicalTrials.gov, number NCT02413372.</p><AbstractText>Between May 12, 2015, and Aug 4, 2016, 184 overweight or obese patients with non-alcoholic steatohepatitis were screened for study inclusion. Of these, 95 (52%) patients were excluded because they no longer met study criteria and 80 (43%) patients entered the placebo lead-in phase. After further exclusions, 75 (94%) patients were randomly assigned to groups, received at least one dose of treatment (25 patients to receive 10 mg pegbelfermin once a day; 24 patients to receive 20 mg pegbelfermin once a week, and 26 patients to receive placebo), and were included in the primary analysis. A prespecified interim analysis at week 8 showed a greater than expected change in the primary outcome and supported early closing of patient enrolment, since this analysis indicated that the full planned sample size was not needed. We observed a significant decrease in absolute hepatic fat fraction in the group receiving 10 mg pegbelfermin daily (-6·8% vs -1·3%; p=0·0004) and in the group receiving 20 mg pegbelfermin weekly (-5·2% vs -1·3%; p=0·008) compared with the placebo group. Most adverse events were mild; the most common events were diarrhoea in eight (16%) of 49 patients treated with pegbelfermin and two (8%) of 26 patients treated with placebo and nausea in seven (14%) patients treated with pegbelfermin and two (8%) patients treated with placebo. There were no deaths, discontinuations due to adverse events, or treatment-related serious adverse events.</AbstractText><AbstractText>Treatment with subcutaneously administered pegbelfermin for 16 weeks was generally well tolerated and significantly reduced hepatic fat fraction in patients with non-alcoholic steatohepatitis. Further study of pegbelfermin is warranted in patients with non-alcoholic steatohepatitis. Additional studies that use liver biopsies would allow for the assessment of pegbelfermin's effects on liver histology. Moreover, further studies should allow assessments of the safety and effectiveness of pegbelfermin in a larger number of patients.</AbstractText><AbstractText>Bristol-Myers Squibb.</AbstractText>