Vitamin D and the regulation of placental inflammation

The vitamin D-activating enzyme 1α-hydroxylase (CYP27B1) and vitamin D receptor (VDR) support anti-inflammatory responses to vitamin D in many tissues. Given the high basal expression of CYP27B1 and VDR in trophoblastic cells from the placenta, we hypothesized that anti-inflammatory effects of vitamin D may be particularly important in this organ. Pregnant wild type (WT) mice i.p. injected with LPS showed elevated expression of mouse Cyp27b1 (4-fold) and VDR (6-fold). Similar results were also obtained after ex vivo treatment of WT placentas with LPS. To assess the functional impact of this, we carried out ex vivo studies using placentas -/- for fetal (trophoblastic) Cyp27b1 or VDR. Vehicle-treated -/- placentas showed increased expression of IFN-γ and decreased expression of IL-10 relative to +/+ placentas. LPS-treated -/- placentas showed increased expression of TLR2, IFN-γ, and IL-6. Array analyses identified other inflammatory factors that are dysregulated in Cyp27b1(-/-) versus Cyp27b1(+/+) placentas after LPS challenge. Data highlighted enhanced expression of IL-4, IL-15, and IL-18, as well as several chemokines and their receptors, in Cyp27b1(-/-) placentas. Similar results for IL-6 expression were observed with placentas -/- for trophoblastic VDR. Finally, ex vivo treatment of WT placentas with the substrate for Cyp27b1, 25-hydroxyvitamin D(3), suppressed LPS-induced expression of IL-6 and the chemokine Ccl11. These data indicate that fetal (trophoblastic) vitamin D plays a pivotal role in controlling placental inflammation. In humans, this may be a key factor in placental responses to infection and associated adverse outcomes of pregnancy.     

Metabolomic linkage reveals functional interaction between glucose-dependent insulinotropic polypeptide and ghrelin in humans

The gastric peptide ghrelin promotes energy storage, appetite, and food intake. Nutrient intake strongly suppresses circulating ghrelin via molecular mechanisms possibly involving insulin and gastrointestinal hormones. On the basis of the growing evidence that glucose-dependent insulinotropic polypeptide (GIP) is involved in the control of fuel metabolism, we hypothesized that GIP and/or insulin, directly or via changes in plasma metabolites, might affect circulating ghrelin. Fourteen obese subjects were infused with GIP (2.0 pmol·kg(-1)·min(-1)) or placebo in the fasting state during either euglycemic hyperinsulinemic (EC) or hyperglycemic hyperinsulinemic clamps (HC). Apart from analysis of plasma ghrelin and insulin levels, GC-TOF/MS analysis was applied to create a hormone-metabolite network for each experiment. The GIP and insulin effects on circulating ghrelin were analyzed within the framework of those networks. In the HC, ghrelin levels decreased in the absence (19.2% vs. baseline, P = 0.028) as well as in the presence of GIP (33.8%, P = 0.018). Ghrelin levels were significantly lower during HC with GIP than with placebo, despite insulin levels not differing significantly. In the GIP network combining data on GIP-infusion, EC+GIP and HC+GIP experiments, ghrelin was integrated into hormone-metabolite networks through a connection to a group of long-chain fatty acids. In contrast, ghrelin was excluded from the network of experiments without GIP. GIP decreased circulating ghrelin and might have affected the ghrelin system via modification of long-chain fatty acid pools. These observations were independent of insulin and offer potential mechanistic underpinnings for the involvement of GIP in systemic control of energy metabolism.     

Ameliorating effects of agomelatine on testicular and epididymal damage induced by methotrexate in rats

The aim of this study was to investigate the possible prophylactic effects of agomelatine (AGO) against testicular and epididymal damage induced by methotrexate (MTX) in rats. Twenty‐four male Wistar albino rats were divided into three groups: Group I (control group), Group II (MTX group: 20 mg/kg MTX, i.p, single dose), and Group III (MTX+AGO group: 20 mg/kg MTX, i.p, single dose+40 mg/kg AGO; gavage, 7 days). The rats were killed under anesthesia 24 hours after the last AGO application. Testicular and epididymal tissues were bilaterally removed for morphometric, biochemical, pathological, and immunohistochemical analyses. Body, testicular, and epididymal weights were measured. Malondialdehyde (MDA), superoxide dismutase, catalase, and glutathione peroxidase levels were measured in testes. Sperm count, hyperemia, edema, inflammatory reaction, degenerated and necrotic cells were evaluated by histopathological analysis. In addition, inducible nitric oxide synthase (iNOS), granulocyte colony‐stimulating factor (G‐CSF), osteopontin (OPN), and heat shock protein‐70 (HSP70) immune reactions were analyzed in testes and epididymides. Decreased epididymal weights, increased MDA levels, decreased sperm count, hyperemia, edema, inflammatory reaction, and degenerated and necrotic cells were observed in the MTX group. In addition, iNOS, HSP70, G‐CSF, and OPN immune reactions were increased. AGO improved morphometric, biochemical, histopathological, and immunohistochemical findings. The present study confirms that MTX induces testicular and epididymal damage both biochemically and immunohistochemically. However, AGO demonstrated ameliorative effects on both biochemical and pathological findings of the current study.     

Amyloid Beta Peptides Affect Pregnenolone and Pregnenolone Sulfate Levels in PC-12 and SH-SY5Y Cells Depending on Cholesterol

Increased amyloid beta (AB) peptide concentration is one of the initiating factors in the neurodegeneration process. It has been suggested that cholesterol induces the synthesis of AB peptide from amyloid precursor protein or facilitates the formation of amyloid plaque by lowering the aggregation threshold of the peptide. It is also shown that AB peptides may affect cholesterol metabolism and the synthesis of steroid hormones such as progesterone and estradiol. Pregnenolone (P) and pregnenolone sulfate (PS) are the major steroids produced from cholesterol in neural tissue. In toxicity conditions, the effect of AB peptides on P and PS levels has not yet been determined. Furthermore, it has not been clearly defined how changes in cellular P and PS levels affect neuronal cell survival. The aim of this study was to determine the effects of AB peptides on cellular changes in P and PS levels depending on the level of their main precursor, cholesterol. Cholesterol and toxic concentrations of AB fragments (AB 25–35, AB 1–40 and AB 1–42) were applied to PC-12 and SH-SY5Y cells. Changes in cellular cholesterol, P and PS levels were determined simultaneously in a dose—and time-dependent manner. The cell viability and cell death types were also evaluated. AB peptides affected both cell viability and P/PS levels. Steroid levels were altered depending on AB fragment type and the cholesterol content of the cells. Treatment with each of the AB fragments alone increased P levels by twofold. However, combined treatment with AB peptides and cholesterol increased P levels by approximately sixfold, while PS levels were increased only about 2.5 fold in both cell lines. P levels in the groups treated with AB 25–35 were higher than those in AB 1–40 and AB 1–42 groups. The cell viabilities were significantly low in the group treated by AB and cholesterol (9 mM). The effect of AB peptides on P levels might be a result of cellular self-defense. On the other hand, the rate of P increase might be playing a key role in the cell death mechanism of AB toxicity depending on cellular cholesterol levels.     

Comparison of prolonged in vivo inhibitory activity of several potent bombesin (BN) antagonists on BN-stimulated amylase secretion in the rat.

New BN analogues designed to be competitive receptor antagonists at the BN/gastrin releasing peptide receptor(s) can exhibit diverse properties ranging from full antagonist, partial agonist or weak agonist activity, depending on the assay system and animal species employed. Here we evaluate the following 3 antagonists which have the most potent receptor affinities in several in vitro assay systems and are representative of 3 main classes of BN antagonists for their in vivo effects on pancreatic amylase secretion in the rat: [D-Cpa6,Phe14,psi 13-14]BN(6-14), [D-Phe6]BN(6-13) propylamide, and [D-Phe6]BN(6-13) methyl ester. After injection in the rat, the methyl ester was clearly the most potent antagonist and completely inhibited BN-stimulated amylase release at the 20 nmol/kg (IV bolus) for about 2 h. In contrast, the propylamide analogue at the 200 nmol/kg (IV bolus) dose produced incomplete inhibition of amylase release. Inhibition was transient and lasted for only about 1 h, possibly reflecting the significant agonist activity of this latter peptide in the rat pancreatic amylase secretion test in vitro. The psi-analogue, while being the longest acting analogue, was also incapable of lowering amylase to basal level at 50 times the BN dose, suggesting that it is a mixed agonist-antagonist in vivo as was also previously shown in vitro in the rat.     

Determination and characterization of thermostable esterolytic activity from a novel thermophilic bacterium Anoxybacillus gonensis A4

A novel hot spring thermophile, Anoxybacillus gonensis A4 (A. gonensis A4) was investigated in terms of capability of tributyrin degradation and characterization of its thermostable esterase activity by the hydrolysis of p-nitrophenyl butyrate (PNPB). It was observed that A. gonensis A4 has an esterase with a molecular weight of 62 kDa. The extracellular crude preparation was characterized in terms of substrate specificity, pH and temperature optima and stability, kinetic parameters and inhibition/activation behaviour towards some chemicals and metal ions. Tributyrin agar assay showed that A. gonensis A4 secreted an esterase and V(max) and K(m) values of its activity were found to be 800 U/L and 176.5 microM, respectively in the presence of PNPB substrate. The optimum temperature and pH, for A. gonensis A4 esterase was 60-80 degrees C and 5.5, respectively. Although the enzyme activity was not significantly changed by incubating crude extract solution at 30-70 degrees C for 1 h, the enzyme activity was fully lost at 80 degrees C for same incubation period. The pH-stability profile showed that original crude esterase activity increased nearly 2-fold at pH 6.0. The effect of some chemicals on crude esterase activity indicated that A. gonensis A4 produce an esterase having serine residue in active site and -SH groups were essential for its activity.     

Visceral leishmaniasis mimicking autoimmune hepatitis, primary biliary cirrhosis, and systemic lupus erythematosus overlap

Visceral leishmaniasis (VL) is a life-threatening infection caused by Leishmania species. In addition to typical clinical findings as fever, hepatosplenomegaly, and cachexia, VL is associated with autoimmune phenomena. To date, VL mimicking or exacerbating various autoimmune diseases have been described, including systemic lupus erythematosus (SLE), rheumatoid arthritis, and autoimmune hepatitis (AIH). Herein, we presented a patient with VL who had overlapping clinical features with SLE, AIH, as well as antimitochondrial antibody (AMA-M2) positive primary biliary cirrhosis.