Galectin-3 is overexpressed in advanced cirrhosis and predicts post-liver transplant infectious complications.

BACKGROUND & AIMS: Patients with advanced cirrhosis often have immune dysfunction and are more susceptible to infections. Galectin-3 is a ß-galactoside-binding lectin implicated in inflammation, immune regulation and liver fibrosis. We aim to investigate galectin-3 expression in advanced cirrhosis and its ability to predict post-transplant infectious complications. METHODS: We collected sera and liver samples from 129 cirrhotic patients at the time of liver transplantation and from an external cohort of 37 patients with alcoholic liver disease including alcoholic hepatitis (AH) at the time of diagnosis. Galectin-3 was assessed by ELISA, real-time PCR, immunohistochemistry and RNA-seq. Receiver operating characteristic curves and Cox proportional-hazards regression analysis were performed to assess the predictive power of galectin-3 for disease severity and post-transplant infections. RESULTS: Increased galectin-3 levels were found in advanced cirrhosis. Galectin-3 significantly correlated with disease severity parameters and inflammatory markers. Galectin-3 had significant discriminating power for compensated and advanced cirrhosis (AUC = 0.78/0.84, circulating/liver galectin-3; p < .01), and was even higher to discriminate severe AH (AUC = 0.95, p < .0001). Cox Proportional-hazard model showed that galectin-3, MELD-Na and the presence of SIRS predict the development of post-transplant infectious complications. Patients with circulating galectin-3 (>16.58 ng/ml) were at 2.19-fold 95% CI (1.12-4.29) increased risk, but when combined with MELD-Na > 20.0 and SIRS, the risk to develop post-transplant infectious complications, increased to 4.60, 95% CI (2.38-8.90). CONCLUSION: Galectin-3 is a novel biological marker of active inflammation and disease severity that could be clinically useful alone or in combination with other scores to discriminate advanced cirrhosis and predict post-transplant infectious complications.

Inulin Improves Diet-Induced Hepatic Steatosis and Increases Intestinal Akkermansia Genus Level.

Hepatic steatosis is characterized by triglyceride accumulation within hepatocytes in response to a high calorie intake, and it may be related to intestinal microbiota disturbances. The prebiotic inulin is a naturally occurring polysaccharide with a high dietary fiber content. Here, we evaluate the effect of inulin on the intestinal microbiota in a non-alcoholic fatty liver disease model. Mice exposed to a standard rodent diet or a fat-enriched diet, were supplemented or not, with inulin. Liver histology was evaluated with oil red O and H&E staining and the intestinal microbiota was determined in mice fecal samples by 16S rRNA sequencing. Inulin treatment effectively prevents liver steatosis in the fat-enriched diet group. We also observed that inulin re-shaped the intestinal microbiota at the phylum level, were Verrucomicrobia genus significantly increased in the fat-diet group; specifically, we observed that Akkermansia muciniphila increased by 5-fold with inulin supplementation. The family Prevotellaceae was also significantly increased in the fat-diet group. Overall, we propose that inulin supplementation in liver steatosis-affected animals, promotes a remodeling in the intestinal microbiota composition, which might regulate lipid metabolism, thus contributing to tackling liver steatosis.

A novel vieuvirus from multidrug-resistant Acinetobacter baumannii.

Bacteriophages are considered the most abundant biological entities on earth, and they are able to modulate the populations of their bacterial hosts. Although the potential of bacteriophages has been accepted as an alternative strategy to combat multidrug-resistant pathogenic bacteria, there still exists a considerable knowledge gap regarding their genetic diversity, which hinders their use as antimicrobial agents. In this study, we undertook a genomic and phylogenetic characterization of the phage Ab11510-phi, which was isolated from a multidrug-resistant Acinetobacter baumannii strain (Ab11510). We found that Ab11510-phi has a narrow host range and belongs to a small group of transposable phages of the genus Vieuvirus that have only been reported to infect Acinetobacter bacteria. Finally, we showed that Ab11510-phi (as well as other vieuvirus phages) has a high level of mosaicism. On a broader level, we demonstrate that comparative genomics and phylogenetic analysis are necessary tools for the proper characterization of phage diversity.

The activation of peroxisome proliferator-activated receptor γ is regulated by Krüppel-like transcription factors 6 & 9 under steatotic conditions.

Liver steatosis is characterised by lipid droplet deposition in hepatocytes that can leads to an inflammatory and fibrotic phenotype. Peroxisome proliferator-activated receptors (PPARs) play key roles in energetic homeostasis by regulating lipid metabolism in hepatic tissue. In adipose tissue PPARγ regulates the adipocyte differentiation by promoting the expression of lipid-associated genes. Within the liver PPARγ is up-regulated under steatotic conditions; however, which transcription factors participate in its expression is not completely understood. Krüppel-like transcription factors (KLFs) regulate various cellular mechanisms, such as cell proliferation and differentiation. KLFs are key components of adipogenesis by regulating the expression of PPARγ and other proteins such as the C-terminal enhancer binding protein (C/EBP). Here, we demonstrate that the transcript levels of Klf6, Klf9 and Pparγ are increased in response to a steatotic insult in vitro. Chromatin immunoprecipitation (ChIp) experiments showed that klf6 and klf9 are actively recruited to the Pparγ promoter region under these conditions. Accordingly, the loss-of-function experiments reduced cytoplasmic triglyceride accumulation. Here, we demonstrated that KLF6 and KLF9 proteins directly regulate PPARγ expression under steatotic conditions.

Transcriptional profiling of fetal hypothalamic TRH neurons.

BACKGROUND: During murine hypothalamic development, different neuroendocrine cell phenotypes are generated in overlapping periods; this suggests that cell-type specific developmental programs operate to achieve complete maturation. A balance between programs that include cell proliferation, cell cycle withdrawal as well as epigenetic regulation of gene expression characterizes neurogenesis. Thyrotropin releasing hormone (TRH) is a peptide that regulates energy homeostasis and autonomic responses. To better understand the molecular mechanisms underlying TRH neuron development, we performed a genome wide study of its transcriptome during fetal hypothalamic development. RESULTS: In primary cultures, TRH cells constitute 2% of the total fetal hypothalamic cell population. To purify these cells, we took advantage of the fact that the segment spanning -774 to +84 bp of the Trh gene regulatory region confers specific expression of the green fluorescent protein (GFP) in the TRH cells. Transfected TRH cells were purified by fluorescence activated cell sorting, various cell preparations pooled, and their transcriptome compared to that of GFP- hypothalamic cells. TRH cells undergoing the terminal phase of differentiation, expressed genes implicated in protein biosynthesis, intracellular signaling and transcriptional control. Among the transcription-associated transcripts, we identified the transcription factors Klf4, Klf10 and Atf3, which were previously uncharacterized within the hypothalamus. CONCLUSION: To our knowledge, this is one of the first reports identifying transcripts with a potentially important role during the development of a specific hypothalamic neuronal phenotype. This genome-scale study forms a rational foundation for identifying genes that might participate in the development and function of hypothalamic TRH neurons.

The Role of the Unfolded Protein Response on Renal Lipogenesis in C57BL/6 Mice.

Renal injury observed in several pathologies has been associated with lipid accumulation in the kidney. While it has been suggested that the accumulation of renal lipids depends on free fatty acids released from adipose tissue, it is not known whether in situ renal lipogenesis due to endoplasmic reticulum (ER) stress contributes to kidney injury. The aim of the present study was to elucidate the role of pharmacological ER stress in renal structure and function and its effect on renal lipid metabolism of C57BL/6 mice. ER stress increased serum creatinine and induced kidney structural abnormalities. Tunicamycin-administered mice developed hyperinsulinemia, augmented lipolysis and increased circulating leptin and adiponectin. Renal unfolded protein response (UPR) gene expression markers, the lipogenic transcription factor SREBP1 and the phosphorylation of eIF2α increased 8 h after tunicamycin administration. At 24 h, an increase in BiP protein content was accompanied by a reduction in p-eIF2α and increased SREBP-1 and FASn protein content, in addition to a significant increase in triglyceride content and a reduction in AMPK. Thus, ER stress induces in situ lipid synthesis, leading to renal lipid accumulation and functional alterations. Future pharmacological and/or dietary strategies must target renal ER stress to prevent kidney damage and the progression of metabolic diseases.

Chaya Leaf Decreased Triglycerides and Improved Oxidative Stress in Subjects With Dyslipidemia.

Chaya is an edible leaf popular in Mexico and Central America because of its high nutritional value. Studies in animal models have demonstrated the beneficial effects of Chaya, which include reduction of circulating lipids and increase in antioxidant activity. However, its hypolipidemic and antioxidant effects have not been demonstrated in humans. Thus, the aim of the present study was to evaluate the effect of Chaya on the lipid profile, lipid peroxidation, inflammation, and peripheral blood mononuclear cell gene expression in a population with dyslipidemia. We performed a single-arm trial in 30 participants with dyslipidemia who consumed 500 mL of Chaya beverage per day over a 6-week period. Interestingly, we observed a significant decrease in serum triglyceride concentration (P < 0.05) and an increase in plasma antioxidant activity and polyphenol concentration (P < 0.005) after 6 weeks of Chaya consumption. This was accompanied by a reduction in the oxidative stress marker MDA (P < 0.0001) and by an increase in the antioxidant enzyme CAT expression in peripheral blood mononuclear cells (P < 0.001). Altogether, our results demonstrate that consumption of Chaya has hypotriglyceridemic and antioxidant effects in subjects with dyslipidemia.

Male Ejaculatory Endophenotypes: Revealing Internal Inconsistencies of the Concept in Heterosexual Copulating Rats.

Distinct manifestations of sexual behavior are conceived as separate phenotypes. Each sexual phenotype is assumed to be associated with a characteristic brain. These notions have justified the phenotyping of heterosexual copulator males based upon their ejaculation's latencies (EL) or frequencies (i.e., cumulative ejaculation number; EN). For instance, men and male rats showing premature, normal or retarded ejaculation are assumed to be distinctive endophenotypes. This concept, nonetheless, contradicts past and recent evidence that supports that sexual behavior is highly variable within each sex, and that the brain sexual functional morphology represents an intricate sexual phenotypic mosaic. Hence, for ejaculatory male endophenotypes to be considered as a valid biological concept, it must show internal consistency at various levels of organization (including genetic architectures), after being challenged by intrinsic and/or extrinsic factors. We then judged the internal consistency of the presumed ejaculatory endophenotypes by assessing whether copulatory behavior and the expression of copulation relevant genes and brain limbic structures are specific to each of the presumed EL- or EN-ejaculatory endophenotypes. To do this, copulating male rats were first phenotyped in groups consistently displaying short, average or long ejaculation latencies or very high, high, average, low or very low EN, based in their copulatory performance. Then, the internal consistency of the presumed EL- or EN-endophenotypes was tested by introducing as covariates of phenotyping other copulatory parameters (e.g., number of intromissions) in addition to EL or EN, or by analyzing the expression levels of genes encoding for estrogen receptor alpha, progesterone receptor, androgen receptor, aromatase, DNA methyl-transferase 3a and DNA methyl-transferase 1 in the amygdala, medial preoptic area, ventromedial hypothalamus and olfactory bulb. We found that even though there were group-level differences in all the variables that were studied, these differences did not add-up to create the presumed EL- or EN-ejaculatory endophenotypes. In fact, the extensive overlapping of copulatory parameters and expression levels of copulation relevant genes in limbic structures across EL- or EN-phenotyped copulating male rats, is not consistent with the hypothesis that distinct ejaculatory endophenotypes exist and that they are associated with specific brain characteristics.

Analysis of circulating blood and tissue biopsy PDX1 and MSX2 gene expression in patients with pancreatic cancer: A case-control experimental study.

Early diagnosis of pancreatic cancer (PC) is based on endoscopic ultrasound (EUS). However, EUS is invasive and requires a high level of technical skill. Recently, liquid biopsies have achieved the same sensitivity and specificity for the diagnosis of numerous pathologies, including cancer. Insulin-promoting factor 1 (PDX1) and Msh-homeobox 2 (MSX2), 2 homeotic genes, have been confirmed to be related to pancreatic oncogenesis.The aim of this study is to establish the diagnostic utility of circulating serum levels of MSX2 and PDX1 expression in patients with PC.A prospective study was conducted from January 2014 to February 2017. Patients with a suspected diagnosis of PC who underwent fine needle aspiration biopsy guided by EUS (EUS-FNA) were included in the study, in addition to non-PC control subjects. Both tissue and blood serum samples were submitted to histopathological analysis and measurement of PDX1 and MSX2 gene expression by means of qRT-PCR.Patients were divided into non-PC, malignant pathology (MP), or benign pathology (BP) groups. Significant differences in both MSX2 [2.05 (1.66-4.60) vs 0.83 (0.49-1.60), P = .006] and PDX1 [2.59 (1.28-10.12) vs 1.02 (0.81-1.17), P = .036] gene expression were found in blood samples of PC compared with non-PC subjects. We also observed a significant increase in MSX2 transcripts in tissue biopsy samples of patients diagnosed with MP compared with those with BP [1.98 (1.44-4.61) and 0.66 (0.45-1.54), respectively, P = .012]. The ROC curves indicate a sensitivity and specificity of 80% for PDX1 and 86% for MSX2.Gene expression of MSX2 in tissue samples obtained by EUS-FNA and serum expression of MSX2 and PDX1 were higher in patients with PC.

BDNF up-regulates pre-pro-TRH mRNA expression in the fetal/neonatal paraventricular nucleus of the hypothalamus. Properties of the transduction pathway.

Brain derived neurotrophic factor (BDNF) increases the levels of pre-pro-thyrotropin releasing hormone (TRH) mRNA in fetal rodent hypothalamic neurons that express TrkB receptors. The present studies aimed at better understanding the role of BDNF in establishing and maintaining the TRH phenotype in hypothalamic neurons during early development. To determine where BDNF regulates the expression of pre-pro-TRH mRNA in vivo, we compared the hypothalamic distribution of pre-pro-TRH mRNA to that of TrkB mRNA. Full-length TrkB (FL-TrkB) mRNA was detected earlier in development than pre-pro-TRH mRNA in the region that gives rise to the paraventricular nucleus of the hypothalamus (PVN). We also evaluated the effects of BDNF on the expression of pre-pro-TRH mRNA in vitro. BDNF up-regulated the levels of pre-pro-TRH mRNA in primary cell cultures obtained from the hypothalamus or the PVN of 17 days old fetuses or newborn rats. This effect was abolished by PD98059, an inhibitor of the mitogen-activated protein kinase kinase (MEK) 1/2 or 5. The effect of BDNF on pre-pro-TRH mRNA levels was reversible. The continuous application of BDNF led to a desensitization of the response at day 10 in vitro, an effect that correlated with a drop in the levels of FL-TrkB protein. In conclusion, BDNF enhances the expression of pre-pro-TRH mRNA in PVN neurons. This effect is reversible, decreases with time, and requires an active MEK. BDNF may contribute to the enhancement of pre-pro-TRH mRNA expression in the hypothalamic PVN during development.

The Krüppel-like factor 4 controls biosynthesis of thyrotropin-releasing hormone during hypothalamus development.

Embryonic neurogenesis is controlled by the activation of specific genetic programs. In the hypothalamus, neuronal thyrotropin-releasing hormone (TRH) populations control important physiological process, including energy homeostasis and autonomic function; however, the genetic program leading to the TRH expression is poorly understood. Here, we show that the Klf4 gene, encoding the transcription factor Krüppel-like factor 4 (Klf4), was expressed in the rat hypothalamus during development and regulated Trh expression. In rat fetal hypothalamic cells Klf4 regulated Trh promoter activity through CACCC and GC motifs present on the Trh gene promoter. Accordingly, hypothalamic Trh expression was down-regulated at embryonic day 15 in the Klf4(-/-) mice resulting in diminished bioactive peptide levels. Although at the neonatal stage the Trh transcript levels of the Klf4(-/-) mice were normal, the reduction in peptide levels persisted. Thus, our data indicate that Klf4 plays a key role in the maturation of TRH expression in hypothalamic neurons.