Oleanolic acid protection against experimental autoimmune myocarditis modulates the microbiota and the intestinal barrier integrity

Background

Autoimmune myocarditis is a cause of dilated cardiomyopathy and heart failure. Recent studies have indicated that leaky gut may allow environmental factors to enter the body and trigger the initiation/development of autoimmune disease. Moreover, there is a growing literature supporting that, beside myocardial fibrosis, a leaky intestinal barrier and gut dysbiosis are pathogenic factors linked to heart failure. The natural triterpene oleanolic acid (OA) has been shown to beneficially influence the severity of the experimental autoimmune myocarditis (EAM), a preclinical model of human myocarditis, via anti-oxidant and immunomodulatory mechanisms. Herein, we investigate gastrointestinal (GI) disturbances and the gut microbiota composition associated with EAM as potential therapeutic target of OA.

Methods and results

BALB/c mice were α-myosin-inmunized to induce EAM and treated with OA (25 mg/kg/day, i.p). On day 21, heart fibrosis and parameters related to gut damage such as oxidative stress (O2- ions, lipid peroxidation), gut permeability (D-lactate; I-FABP), inflammation and mucins were determined in serum and/or colon. Fecal microbial profiles were identified by 16S rRNA gene sequencing analysis. Firstly, histological analysis of hearts showed presence of fibrosis (Sirius Red stain) in EAM mice, whereas these effects were not detectable in myocardium from healthy or OA-treated EAM mice. In addition, OA preserved the mucin-containing goblet cells along the colon (Alcian Blue/PAS stain). Consistently, serum levels of the epithelial gut damage markers, including D-lactate and iFABP were significantly reduced in OA treated-EAM mice. The beneficial OA effects also included a decrease in the pro-inflammatory mediators sPLA2-IIA and IL-1β and a protection from the oxidative stress response (DHE stain and TBARS) in serum and colonic tissue of EAM-mice. Furthermore, gut microbiota composition showed a lower bacterial diversity and different relative abundance of certain bacterial taxa in EAM-mice compared to control mice. The families of Muribaculaceae, Lachnospiraceae, and Ruminococcaceae were significantly affected in EAM mice, and only Muribaculaceae recovered levels similar to the healthy-control group, after treatment with OA.

Conclusion

Our data show that in addition to the heart, the intestinal barrier and gut microbiota are altered in myocarditis, and that OA treatment could ameliorate this profile. Our data contribute to the idea that gut dysbiosis and GI dysfunction influences myocarditis pathogenesis, and provides new findings regarding the beneficial activity of OA in EAM, suggesting that it may be an interesting candidate to be explored for the treatment of human patients.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): MINECO, ISCIII, CIBERCV-ISCIII

P6284The antioxidant MitoQ protects against intestinal disturbances in the experimental autoimmune model of myocarditis

Purpose

Myocarditis and dilated cardiomyopathy represent the acute and chronic phases of an inflammatory disease of the myocardium, for which no standardized treatment is currently available in clinical practice. Myocardial fibrosis an oxidative stress are pathogenic factors associated with these processes. However, new research has found that gut health can be linked to some cardiac conditions. Thus, in this study we investigated whether intestinal disturbances are present in myocarditis, using a murine experimental autoimmune model (EAM) that mimics human myocarditis, as well as the potential beneficial effect of treatment with the mitochondrial antioxidant, MitoQ.

Methods and results

EAM was induced in BALB/c mice with a myocardiogenic peptide and mice were treated with MitoQ (50 mg/kg/day, i.p). On day 21 (acute phase), we assessed signs of heart injury (e.g. hypertrophy, fibrosis, oxidative stress) and parameters related to gut damage such as accumulation of reactive oxigen species (superoxide anion: O2·−), inflammation (IL-1β, IL-33, TNFα), microbial translocation (sCD14; intestinal fatty acid binding protein, I-FABP) and mucins in serum and/or intestine. MitoQ teatment significantly reduced the high heart weight/body weight ratio (HW/BW) of EAM mice, a characteristic hallmark of cardiac hyperthropy. Histological analysis of hearts showed presence of fibrosis (Sirius Red stain) and high O2·− levels (DHE stain) in EAM mice whereas these effects were not detectable in cardiac tissue from healthy or MitoQ-treated EAM mice. In addition, the enhanced O2·− ions (DHE stain) and mucin loss (Alcian Blu/PAS stain) found in colon, ileum, jejunum and duodenum sections from EAM mice were attenuated by MitoQ treatment. The systemic markers associated to intestinal barrier disruption, sCD14 and I-FABP, were found strongly increased in serum from EAM mice, and MitoQ prevents this rise. The beneficial MitoQ effects were also associated with a decrease in the pro-inflammatory cytokines TNFα, IL-33 and IL-1β, both in serum and colonic tissue of treated-EAM mice, as well as a reduction of the myeloperoxidase activity in colon, compared with untreated EAM mice.

Conclusion

Our data show that in addition to the heart, the intestinal tissue is also damaged in the preclinical model of experimental autoimmune myocarditis, and that MitoQ treatment could reverse this profile. Since there are systemic markers released from the intestine, therapeutic strategies targeting to prevent the intestinal oxidative stress and its associated gut barrier dysfunction, could contribute to the amelioration of the disease.

Acknowledgement/Funding

SAF2016-81063; CIBERCV

Incidence rates and trends of hip/femur fractures in five European countries: comparison using e-healthcare records databases

Hip fractures represent a major public health challenge worldwide. Multinational studies using a common methodology are scarce. We aimed to estimate the incidence rates (IRs) and trends of hip/femur fractures over the period 2003-2009 in five European countries. The study was performed using seven electronic health-care records databases (DBs) from Denmark, The Netherlands, Germany, Spain, and the United Kingdom, based on the same protocol. Yearly IRs of hip/femur fractures were calculated for the general population and for those aged ≥50 years. Trends over time were evaluated using linear regression analysis for both crude and standardized IRs. Sex- and age-standardized IRs for the UK, Netherlands, and Spanish DBs varied from 9 to 11 per 10,000 person-years for the general population and from 22 to 26 for those ≥50 years old; the German DB showed slightly higher IRs (about 13 and 30, respectively), whereas the Danish DB yielded IRs twofold higher (19 and 52, respectively). IRs increased exponentially with age in both sexes. The ratio of females to males was ≥2 for patients aged ≥70-79 years in most DBs. Statistically significant trends over time were only shown for the UK DB (CPRD) (+0.7% per year, P < 0.01) and the Danish DB (-1.4% per year, P < 0.01). IRs of hip/femur fractures varied greatly across European countries. With the exception of Denmark, no decreasing trend was observed over the study period.

Genetic abnormalities associated with the t(12;21) and their impact in the outcome of 56 patients with B-precursor acute lymphoblastic leukemia

The ETV6/RUNX1 rearrangement is found in 20-30% of children with B-cell precursor acute lymphoblastic leukemia and is associated with a good outcome. To determine the cytogenetic and molecular abnormalities associated with the ETV6/RUNX1 rearrangement and the influence of this rearrangement in patients' evolution, we analyzed the molecular cytogenetic profiles of 56 children with this rearrangement and B-cell precursor acute lymphoblastic leukemia. Secondary changes detected with conventional cytogenetics and with fluorescence in situ hybridization were found in 71.4% of cases, the most frequent being the loss of the normal ETV6 allele, 12p aberrations, duplication of the fusion gene, and trisomy 21, as in replicating the results of previous studies. In this preliminary series, with a mean follow-up of 69.3 months, secondary abnormalities did not influence patients' outcome. It seems therefore that the prognostic value of the t(12;21) does not vary and that ETV6/RUNX1 rearrangement is an independent indicator of good prognosis.

[Study of the extent and rate of bioavailability of ibuprofen tablets]

The extent and rate of bioavailability of ibuprofen tablets were determined in a crossover clinical trial in 18 healthy subjects of both sexes. The study was approved by the local ethical committee and was authorized by the Spanish Medicines Agency. Volunteers signed an informed consent form and were included in accordance with the standard procedures for this type of study. In two distinct sessions participants received a single 600 mg ibuprofen dose as Gelofeno(®) 600 mg tablets (Laboratorios Gelos S.L.), or as the reference formulation, Neobrufen(®) 600 mg tablets. Ibuprofen concentrations in plasma were determined immediately before (0 h) and 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12 and 24 h after drug administration. The pharmacokinetic parameters were then calculated. In all subjects, Gelofeno(®) 600 mg tablets produced plasma concentrations above the quantification limit between 15 and 30 minutes after administration, and in 9 (50%) of these subjects maximal plasma concentrations were reached at 1 h. The median t(max) was 1.25 h, and the average maximal plasma concentration was 40.7 mg/l. Gelofeno(®) 600 mg tablets were bioequivalent both in extent and in rate of bioavailability compared with the reference drug. The formulation showed good tolerability and no medication-related adverse effects were observed.

Influence of hepatocyte-rich liver cell mixture and liver fibroblasts on prolonging graft islet survival in rats without immunosuppressive drugs

BACKGROUND

We noted that a liver cell suspension, made up of a mixture of several kinds of hepatic cells, affected allogenic islet survival when it was transplanted into the liver, mixed with the islets or separately.

AIM

To study if this effect was related to a liver cell mixture rich in hepatocytes (hp) or to liver fibroblasts (fb).

METHODS

We studied 14 groups of rats: (A) a sham group with saline; (B) a group receiving transplantation with hepatic cells alone; (C) a control group, with islets alone via the portal vein, without hepatic cells (hp or fb). For the other groups, we used a different ratio of cells/islets (100 : 1, 150 : 1 and 200 : 1) and different co-transplantation techniques with both types of cells. For the D, E, J groups, a mixture of hepatocytes (hepatocyte-rich liver cell mixture) or fibroblasts with islets was injected into the portal vein. For the other groups, we used a sequential procedure with a 15 minute interval between a first injection of hp or fb into the portal vein or into the vena cava, and a second injection of islets always into the portal vein; thus, it was a sequential portal/portal procedure with hepatocyte-rich liver cell mixture (hp) (F, G) or fibroblasts (K, L) and a sequential cava/portal with hp (H, I) or fibroblasts (M, N).

RESULTS

Most of the co-transplantation groups showed functional islets (blood glucose < 250 mg/dl) on the first or second day of transplantation; after several days they once again had high glucose levels, though not as high as pre-transplantation. There was statistical significance (p < 0.001) between the presence or not of hepatic cells to obtain prolongation of graft survival (blood glucose < 250 mg/dl). Statistical significance (p < 0.001) was found for several sequential groups with hp (F, I) and fb (K, L). It was also remarkable that 3 rats (37.5 %) from the I group (sequential cava/portal with hp/islets 200 : 1) were euglycemic (blood glucose < 150 mg/dl) for more than 3 months. ANOVA showed a large interaction between the type of transplant performed and the cellular ratio used, with a significance of p < 0.001. Histological studies in rats with prolonged euglycemia, showed insulin-producing cell aggregates in the liver, while there was a remarkable decrease in insulin-producing cells in the remaining islets of pancreatic tissue.

CONCLUSION

The results showed a marginal prolongation of islet graft survival when they are co-transplanted with a hepatocyte-rich liver cell mixture or with liver fibroblasts. The mechanism does not seem to be a cellular interaction between different hepatic cells and islets, but some kind of cellular interaction or released factor from either two cell types on the immune system, blocking or modulating it, at least temporarily.

ETV6/RUNX1 rearrangement in childhood B-precursor acute lymphoblastic leukemia with normal karyotypes or without cytogenetic results

The ETV6/RUNX1 rearrangement (also known as TEL/AML1) was evaluated in 39 children with B-precursor acute lymphoblastic leukemia (ALL) who had a normal karyotype or lack of mitoses. Forty-one point six percent of patients with normal karyotypes and 66.6% of patients without mitoses presented with the ETV6/RUNX1 rearrangement. In addition to this rearrangement, eight patients showed loss of the normal ETV6 allele; of three patients without mitoses, two showed an extra signal of the RUNX1 gene and the third showed the fusion gene duplicated and loss of the normal ETV6 allele. One patient without the ETV6/RUNX1 rearrangement and without mitoses showed two extra signals of the RUNX1 gene.

Mitochondrial DNA haplotyping of Testudo graeca on both continental sides of the Straits of Gibraltar

Testudo graeca is an endangered species of tortoise that inhabits Mediterranean areas of Africa, Asia, and Europe. Western populations are found on both sides of the Straits of Gibraltar. The effects of geographical isolation on genetic divergence were assessed by the sequence analysis of two mitochondrial DNA regions of the 12S rRNA and cytochrome b genes. Four different haplotypes were identified. A single haplotype was shared by all Spanish and some east Moroccan specimens. Two haplotypes were unique to the west Moroccan T. graeca populations and allowed the clear discrimination between individual specimens found west of the Moulouya River. Phylogenetic analysis based on the estimation of nucleotide sequence distances of the haplotypes suggests an African origin for the Spanish populations and a subspecies status for the west Moroccan pool.

Phylogeography of African fruitbats (Megachiroptera)

Joint sequences from the mitochondrial cytochrome b and 16S rRNA genes of a wide representation of Megachiroptera were employed to evaluate the traditional taxonomic arrangement of African fruitbats and to examine their origins and evolutionary relationships. The resulting phylogenetic hypotheses are inconsistent with the previously established morphology-based subdivisions of Megachiroptera at the suprageneric level. Findings indicate the existence of an African clade, which appears to be formed by two endemic clades: the epomophorines and the myonycterines. According to our topologies, the genus Rousettus is monospecific in mainland Africa. Its traditional subgenera Stenonycteris and Lissonycteris appear closer to the myonycterines than to Rousettus. Topologies also indicate that the African genus Eidolon is not phylogenetically related to any other African fruitbat. It would seem that the arrival of fruitbats in Africa was a complex process involving at least three independent colonization events. One event took place probably in the Miocene via forested corridors that connected the African and Asian rain forest blocks, as for other groups of mammals. The resulting lineage diversified into most of the extant African fruitbats. Related to this clade, the Rousettus species group is thought to have arrived in Africa in more recent times, possibly by progressive displacement from the East through India. Finally, the present topologies suggest an independent colonization of Africa by ancestors of Eidolon.

Molecular phylogeny and morphological homoplasy in fruitbats

The present study evaluates the evolutionary framework of the Old World fruitbats based on the cytochrome b and 16S rRNA mitochondrial gene sequences from a wide range of taxa. Phylogenetic analyses indicated that morphology-based subfamilies and most suprageneric groups are nonnatural assemblages. They also support the existence of an endemic African clade of fruitbats. The discrepancy between the evolutionary relationships yielded by molecular and morphological data sets may be, at least in part, explained by the recurrent retention of primitive morphology (Rousettus-like) across different lineages. The maintenance of primitive characters in different groups of flying foxes, as well as morphological convergence in nectar-feeding bats and possibly also in short-muzzle bats, may have led to high levels of homoplasy, resulting in misleading taxonomic arrangements. This may be particularly so with respect to high taxonomic levels based on morphological characters.

Nursing assessment and management of pain in critically ill children

OBJECTIVES

To describe how nurses assess and manage pain in critically ill children.

DESIGN

Descriptive, comparative research design, with use of the Indicators of Pain in Critically Ill Children assessment tool.

SETTING

Twelve-bed pediatric intensive care unit in a metropolitan general hospital with a level II pediatric trauma center.

PARTICIPANTS

Twenty-four pediatric intensive care unit nurses who conducted 112 assessments of 25 critically ill children.

RESULTS

Pain indicators selected most frequently by nurses included cardiovascular and respiratory changes (increased heart rate, respiratory rate, and blood pressure), followed by behavioral indicators (irritable/fussy, verbalizing pain, crying), and neuromuscular responses (tenseness/rigidity, squirming, drawing up legs). The average number of pain indicators selected during each medication event was 5.3. More indicators were selected for trauma, surgery, and younger patients; fewer indicators were selected for patients receiving ventilation treatment.

CONCLUSION

Pain assessment of critically ill children includes unique indicators, as compared to less sick children, and must take into account the child's decreased ability to communicate pain.

Polyribosomes of normal and SV40(MK 2 ) virus-infected LLC-MK 2 cells

LLC-MK₂ cells are susceptible to SV40(MK₂) virus which produce a nonlytic infection with small virus yield. A very small input multiplicity of virus produces marked effects. After an early stage of protein synthesis inhibition, virus activity is associated with the formation of polyribosomes, especially those of fractions 7 (tetraribosomes), 5 (pentamers), and 1 (polysomes with 7 and more ribosomal units). This is followed by changes in ribosomal activity, leading to a generalized inhibition of protein synthesis through the formation of inactive polyribosomes by subunit binding, which may be due to alteration of the dissociation factors, or to the modification of the ribosomal proteins. Inhibition of protein synthesis is responsible for the low virus yield.