Severe Leptospirosis in a Mexican Woman.

OBJECTIVE: To describe a severe case of infection by Leptospira in a woman in the northwest of Mexico. CASE REPORT: A 55-yearold woman from Sonora, México arrived at the Intensive Care Unit due to severe multiple organ failure primarily affecting the respiratory, renal and hepatic systems. Diagnostic tests were performed, and they were positive for anti-Leptospira antibodies, IgM and IgG; and spirochetes were observed on dark field microscopy and confirmed by Polymerase Chain Reaction (PCR). Doxycycline and platelet apheresis transfusion were used as treatment, which led to a very slow recovery. CONCLUSION: The information presented in this study may help in the identification of pathology caused by spirochetes. This case report is the first to present a case of severe leptospirosis in Sonora, México.

Hypoxia inducible factor -1 regulates WSSV-induced glycolytic genes in the white shrimp Litopenaeus vannamei.

Hypoxia-inducible factor -1 (HIF-1) is a transcriptional factor that regulates the expression of several glycolytic genes. The white spot syndrome virus (WSSV) induces a shift in glycolysis that favors viral replication in white shrimp Litopenaeus vannamei. HIF-1 is related to the pathogenesis of the WSSV infection through the induction of metabolic changes in infected white shrimp. Although the WSSV infection is associated with metabolic changes, the role of HIF-1 on key glycolytic genes during the WSSV infection has not been examined. In this work, we evaluated the effect of HIF-1α silencing on expression and activity of glycolytic enzymes (Hexokinase-HK, phosphofructokinase-PFK and pyruvate kinase-PK) along with the glucose transporter 1 (Glut1), regulatory enzymes (glucose-6-phosphate dehydrogenase-G6PDH and pyruvate dehydrogenase-PDH), and metabolic intermediates of glycolysis (glucose-6-phosphate-G6P and pyruvate). The expression of Glut1 increased in each tissue evaluated after WSSV infection, while HK, PFK and PK gene expression and enzyme activities increased in a tissue-specific manner. G6PDH activity increased during WSSV infection, and its substrate G6P decreased, while PDH activity decreased and its substrate pyruvate increased. Silencing of HIF-1α blocked the WSSV-induced Glut1 and glycolytic genes upregulation and enzyme activity in a tissue-specific manner. We conclude that HIF-1 regulates the WSSV-induced glycolysis through induction of glycolytic genes contributing to glucose metabolism in tissues of infected shrimp. Also, the inhibition, and activation of regulatory genes are likely to decrease the availability of the raw materials essential for WSSV replication and increase oxidative metabolism.

Th1/Th17 Cytokine Profile is Induced by Macrophage Migration Inhibitory Factor in Peripheral Blood Mononuclear Cells from Rheumatoid Arthritis Patients.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is an immunoregulatory cytokine that plays a crucial role as a regulator of the innate and adaptive immune responses and takes part in the destructive process of the joint in rheumatoid arthritis (RA) by promoting angiogenesis and inducing proinflammatory cytokines and matrix metalloproteinases (MMP). We evaluated if recombinant human MIF (rhMIF) induces the production of TNF-α, IFN-γ, IL-1ß, IL-6, IL-10, IL-17A, and IL- 17F in peripheral blood mononuclear cells (PBMC) from RA patients and control subjects (CS). METHODS: The PBMC from RA patients and CS were stimulated for 24 hours with combinations of LPS, rhMIF or the MIF antagonist ISO-1. Cytokine profiles were measured using a multiplex immunoassay and, macrophage migration inhibitory factor (MIF) was determined by ELISA kit. RESULTS: The PBMC of CS and RA produced Th1 and Th17 cytokines under stimulation with rhMIF, however, this effect was higher in the cells of RA patients. The rhMIFstimulated PBMC from RA patients produced higher levels of Th1 and Th17 cytokines in comparison with unstimulated cells: TNF-α (538.81 vs. 5.02 pg/mL, p<0.001), IFN-γ (721.90 vs. 8.40 pg/mL, p<0.001), IL-1ß (150.14 vs. 5.17 pg/mL, p<0.05), IL-6 (19769.70 vs. 119.85 pg/mL, p<0.001), IL-17A (34.97 vs. 0.90 pg/mL, p<0.01) and IL-17F (158.43 vs. 0.92 pg/mL, p<0.001). CONCLUSION: These results highlight the potential role of MIF in the establishment of the chronic inflammatory process in RA via Th1 and Th17 cytokine profile induction and provide new evidence of the role of MIF to stimulate the IL-17A and IL-17F expression in PBMC from RA and CS.

Betaine Aldehyde Dehydrogenase expression during physiological cardiac hypertrophy induced by pregnancy.

Betaine Aldehyde Dehydrogenase (betaine aldehyde: NAD(P)+ oxidoreductase, (E.C. 1.2.1.8; BADH) catalyze the irreversible oxidation of betaine aldehyde (BA) to glycine betaine (GB) and is essential for polyamine catabolism, γ-aminobutyric acid synthesis, and carnitine biosynthesis. GB is an important osmolyte that regulates the homocysteine levels, contributing to a vascular risk factor reduction. In this sense, distinct investigations describe the physiological roles of GB, but there is a lack of information about the GB novo synthesis process and regulation during cardiac hypertrophy induced by pregnancy. In this work, the BADH mRNA expression, protein level, and activity were quantified in the left ventricle before, during, and after pregnancy. The mRNA expression, protein content and enzyme activity along with GB content of BADH increased 2.41, 1.95 and 1.65-fold respectively during late pregnancy compared to not pregnancy, and returned to basal levels at postpartum. Besides, the GB levels increased 1.53-fold during pregnancy and remain at postpartum. Our results demonstrate that physiological cardiac hypertrophy induced BADH mRNA expression and activity along with GB production, suggesting that BADH participates in the adaptation process of physiological cardiac hypertrophy during pregnancy, according to the described GB role in cellular osmoregulation, osmoprotection and reduction of vascular risk.

Alternative splicing generates two lactate dehydrogenase subunits differentially expressed during hypoxia via HIF-1 in the shrimp Litopenaeus vannamei.

Metabolic adjustment to low oxygen exposure (hypoxia) in the white shrimp Litopenaeus vannamei implies a shift to anaerobic metabolism. Lactate dehydrogenase (LDH) is a key enzyme of the anaerobic metabolism described in most organisms. The structure and expression of the LDH gene, as well as the LDH isoenzymes in marine crustacean are not well defined. In the present study we characterized a gene that codes for two LDH subunits, measured their expression and detected the isoenzymes in tissues from white shrimp. We also silenced the transcriptional activator hypoxia inducible factor 1 (HIF-1) to elucidate the regulation of LDH in tissues from white shrimp in response to hypoxia. The complete LDH gene coding sequence is 7571 bp (LvanLDH) and encodes two different LDH subunits (LDHvan-1 and LDHvan-2) generated by alternative splicing and composed of 332 amino acids with conserved domains important for the function and regulation. Phylogenetic analysis shows that LvanLDH -1 and -2 are closer to the invertebrate counterparts. The LDHvan-1 transcript increased 2.5-fold after hypoxia in gills but not in hepatopancreas, while the LDHvan-2 transcript decreased 14-fold in muscle but not in gills and hepatopancreas. Three bands with LDH activity of ∼60­90 kDa were detected in hepatopancreas, while one band of ∼140 kDa was detected in gills and muscle. The silencing of HIF-1 blocked the increase of LDH mRNA and activity produced by hypoxia in gills. These results demonstrate a single gene for LDH (LvanLDH) that by alternative splicing generates two different LDH subunits (LDHvan-1 and LDHvan-2) that are expressed in a tissue-specific manner during hypoxia via the HIF-1 pathway.

Prolonged fasting increases purine recycling in post-weaned northern elephant seals.

Northern elephant seals are naturally adapted to prolonged periods (1-2 months) of absolute food and water deprivation (fasting). In terrestrial mammals, food deprivation stimulates ATP degradation and decreases ATP synthesis, resulting in the accumulation of purines (ATP degradation byproducts). Hypoxanthine-guanine phosphoribosyl transferase (HGPRT) salvages ATP by recycling the purine degradation products derived from xanthine oxidase (XO) metabolism, which also promotes oxidant production. The contributions of HGPRT to purine recycling during prolonged food deprivation in marine mammals are not well defined. In the present study we cloned and characterized the complete and partial cDNA sequences that encode for HGPRT and xanthine oxidoreductase (XOR) in northern elephant seals. We also measured XO protein expression and circulating activity, along with xanthine and hypoxanthine plasma content in fasting northern elephant seal pups. Blood, adipose and muscle tissue samples were collected from animals after 1, 3, 5 and 7 weeks of their natural post-weaning fast. The complete HGPRT and partial XOR cDNA sequences are 771 and 345 bp long and encode proteins of 218 and 115 amino acids, respectively, with conserved domains important for their function and regulation. XOR mRNA and XO protein expression increased 3-fold and 1.7-fold with fasting, respectively, whereas HGPRT mRNA (4-fold) and protein (2-fold) expression increased after 7 weeks in adipose tissue and muscle. Plasma xanthine (3-fold) and hypoxanthine (2.5-fold) levels, and XO (1.7- to 20-fold) and HGPRT (1.5- to 1.7-fold) activities increased during the last 2 weeks of fasting. Results suggest that prolonged fasting in elephant seal pups is associated with increased capacity to recycle purines, which may contribute to ameliorating oxidant production and enhancing the supply of ATP, both of which would be beneficial during prolonged food deprivation and appear to be adaptive in this species.

Antioxidant capacity develops with maturation in the deep-diving hooded seal.

Maturation in hooded seals is characterized by the rapid development of their physiological diving capacity and is accompanied by increases in oxidant production but not oxidative damage. To test the hypothesis that the antioxidant system of hooded seals develops as they transition from a terrestrial to an aquatic environment, we obtained the complete cDNA sequence that encodes the NF-E2-related factor 2 (Nrf2), a central regulator of the antioxidant response, and compared Nrf2 mRNA and protein expression levels in muscle samples from neonate, weaned pups and adult hooded seals, along with glutathione (GSH) levels and the activity/protein content of the antioxidant enzymes catalase, glutathione peroxidase (GPx), peroxyredoxin VI (PrxVI), thioredoxin 1 (Trx1), thioredoxin reductase (TrxR), glutaredoxin 1 (Glrx1), glutathione disulphide reductase, glutathione S-transferase and glutamate-cysteine ligase. The Nrf2 of the hooded seal is 1822 bp long and encodes a protein of 606 amino acids with a leucine zipper domain and Keap1-mediated proteosomal degradation residues, which are key for Nrf2 function and regulation. Although neither Nrf2 mRNA nor Nrf2 nuclear protein content are higher in adults than in pups, GSH levels along with GPx, PrxVI, Trx1, TrxR and Glrx1 activity/protein content increase with maturation, suggesting that the potential for peroxide removal increases with development in hooded seals, and that these enzymes contribute to the regulation of the intracellular redox state and the prevention of oxidative damage in these deep-diving mammals.