Microbiota Signals during the Neonatal Period Forge Life-Long Immune Responses.

The microbiota regulates immunological development during early human life, with long-term effects on health and disease. Microbial products include short-chain fatty acids (SCFAs), formyl peptides (FPs), polysaccharide A (PSA), polyamines (PAs), sphingolipids (SLPs) and aryl hydrocarbon receptor (AhR) ligands. Anti-inflammatory SCFAs are produced by Actinobacteria, Bacteroidetes, Firmicutes, Spirochaetes and Verrucomicrobia by undigested-carbohydrate fermentation. Thus, fiber amount and type determine their occurrence. FPs bind receptors from the pattern recognition family, those from commensal bacteria induce a different response than those from pathogens. PSA is a capsular polysaccharide from B. fragilis stimulating immunoregulatory protein expression, promoting IL-2, STAT1 and STAT4 gene expression, affecting cytokine production and response modulation. PAs interact with neonatal immunity, contribute to gut maturation, modulate the gut-brain axis and regulate host immunity. SLPs are composed of a sphingoid attached to a fatty acid. Prokaryotic SLPs are mostly found in anaerobes. SLPs are involved in proliferation, apoptosis and immune regulation as signaling molecules. The AhR is a transcription factor regulating development, reproduction and metabolism. AhR binds many ligands due to its promiscuous binding site. It participates in immune tolerance, involving lymphocytes and antigen-presenting cells during early development in exposed humans.

Corrigendum to "Sphingolipids as Mediators in the Crosstalk between Microbiota and Intestinal Cells: Implications for Inflammatory Bowel Disease".

[This corrects the article DOI: 10.1155/2016/9890141.].

Activity of neutral and alkaline ceramidases on fluorogenic N-acylated coumarin-containing aminodiols.

Ceramidases catalyze the cleavage of ceramides into sphingosine and fatty acids. Previously, we reported on the use of the RBM14 fluorogenic ceramide analogs to determine acidic ceramidase activity. In this work, we investigated the activity of other amidohydrolases on RBM14 compounds. Both bacterial and human purified neutral ceramidases (NCs), as well as ectopically expressed mouse neutral ceramidase hydrolyzed RBM14 with different selectivity, depending on the N-acyl chain length. On the other hand, microsomes from alkaline ceramidase (ACER)3 knockdown cells were less competent at hydrolyzing RBM14C12, RBM12C14, and RBM14C16 than controls, while microsomes from ACER2 and ACER3 overexpressing cells showed no activity toward the RBM14 substrates. Conversely, N-acylethanolamine-hydrolyzing acid amidase (NAAA) overexpressing cells hydrolyzed RBM14C14 and RBM14C16 at acidic pH. Overall, NC, ACER3, and, to a lesser extent, NAAA hydrolyze fluorogenic RBM14 compounds. Although the selectivity of the substrates toward ceramidases can be modulated by the length of the N-acyl chain, none of them was specific for a particular enzyme. Despite the lack of specificity, these substrates should prove useful in library screening programs aimed at identifying potent and selective inhibitors for NC and ACER3.

The Use of Therapy Dogs in the Pediatric COVID-19 Vaccination at the University of Puerto Rico Medical Sciences Campus.

Pet ownership and therapy dogs as companion animals and emotional support have potential health benefits. We report the experiences at a COVID-19 vaccination center after authorizing children's vaccines. When the Pfizer-BioNTech vaccine for children aged 5 to 11 years was authorized for emergency use, we adapted the center's space to receive children, adding cartoon posters and balloons and using children's adhesive bandages, among others. Located at a Campus with six health professional schools, medical students dressed as storybook or movie characters. Children were asked to make drawings during the post vaccination observation period. We incorporated therapy dogs as part of our strategy for a child-friendly center during vaccination activities. Parents expressed that the COVID-19 immunization seemed to be better accepted by children as the dogs in the center entertained them. Many children were in close contact with the dogs while receiving the shots, caressing them, or having the small dogs on their laps. Children's drawings reflected colors, flowers, families, images of happiness, dogs with their names, their own pets, and superhero characters. There were no negative images of syringes, injections, or germs. To our knowledge, this was the only vaccine center in Puerto Rico that implemented therapy dogs as a strategy to create a friendly environment for COVID 19 immunization efforts targeted for children. Based on this experience, we encourage the use of therapy dogs in other immunization activities and will further gather prospective data in the future.

Acid ceramidase as a therapeutic target in metastatic prostate cancer.

Acid ceramidase (AC) catalyzes the hydrolysis of ceramide into sphingosine, in turn a substrate of sphingosine kinases that catalyze its conversion into the mitogenic sphingosine-1-phosphate. AC is expressed at high levels in several tumor types and has been proposed as a cancer therapeutic target. Using a model derived from PC-3 prostate cancer cells, the highly tumorigenic, metastatic, and chemoresistant clone PC-3/Mc expressed higher levels of the AC ASAH1 than the nonmetastatic clone PC-3/S. Stable knockdown of ASAH1 in PC-3/Mc cells caused an accumulation of ceramides, inhibition of clonogenic potential, increased requirement for growth factors, and inhibition of tumorigenesis and lung metastases. We developed de novo ASAH1 inhibitors, which also caused a dose-dependent accumulation of ceramides in PC-3/Mc cells and inhibited their growth and clonogenicity. Finally, immunohistochemical analysis of primary prostate cancer samples showed that higher levels of ASAH1 were associated with more advanced stages of this neoplasia. These observations confirm ASAH1 as a therapeutic target in advanced and chemoresistant forms of prostate cancer and suggest that our new potent and specific AC inhibitors could act by counteracting critical growth properties of these highly aggressive tumor cells.

3-Deoxy-3,4-dehydro analogs of XM462. Preparation and activity on sphingolipid metabolism and cell fate.

Three analogs of the dihydroceramide desaturase inhibitor XM462 are reported. The compounds inhibit both dihydroceramide desaturase and acid ceramidase, but with different potencies depending on the N-acyl moiety. Other enzymes of sphingolipid metabolism, such as neutral ceramidase, acid sphingomyelinase, acid glucosylceramide hydrolase, sphingomyelin synthase and glucosylceramide synthase, are not affected. The effect on the sphingolipidome of the two best inhibitors, namely (R,E)-N-(1-hydroxy-4-(tridecylthio)but-3-en-2-yl)octanamide (RBM2-1B) and (R,E)-N-(1-hydroxy-4-(tridecylthio)but-3-en-2-yl)pivalamide (RBM2-1D), is in accordance with the results obtained in the enzyme assays. These two compounds reduce cell viability in A549 and HCT116 cell lines with similar potencies and both induced apoptotic cell death to similar levels than C8-Cer in HCT116 cells. The possible therapeutic implications of the activities of these compounds are discussed.

Parasporin A13-2 of Bacillus thuringiensis Isolates from the Papaloapan Region (Mexico) Induce a Cytotoxic Effect by Late Apoptosis against Breast Cancer Cells.

The protein A13-2 was obtained from Bacillus thuringiensis strains isolated from the Papaloapan watershed region (Oaxaca, Mexico). The cytotoxic activity of parasporal inclusions was studied against breast cancer cell line (MCF-7) and normal cell (human peripheral blood mononuclear cells). The MTT, the formation of reactive species, nitric oxide, free cell DNA, and the type of death cellular were assessed. The protein A13-2 shows the highest cytotoxic activity against MCF-7 (13% cell viability at 6 µg/mL), the extracellular DNA increases, and it shows no stress for reactive species or nitric oxide. Besides, the A13-2 parasporin shows no toxicity to peripheral blood mononuclear cells, and it does not generate changes in nitric oxide levels or free cell DNA. Due to that, the cytotoxic effect of A13-2 was specific for MCF-7, and it does not affect normal cells. According to microscopy and flow cytometry, A13-2 parasporin leads to the death of MCF-7 cells by late apoptosis together with necrosis and without allowing the triggering of the survival mechanisms. When analyzed together, our results show for the first time that the A13-2 protein isolated from Mexican strains of B. thuringiensis preferentially kills MCF- 7 (cancer cells) over HEK 293 and PBMC cell lines (normal cells), thus representing a promising alternative for the treatment of cancer breast.

A simple fluorogenic method for determination of acid ceramidase activity and diagnosis of Farber disease.

Acid ceramidase (aCDase) is one of several enzymes responsible for ceramide degradation within mammalian cells. As such, aCDase regulates the intracellular levels of the bioactive lipid ceramide. An inherited deficiency of aCDase activity results in Farber disease (FD), also called lipogranulomatosis, which is characterized by ceramide accumulation in the tissues of patients. Diagnosis of FD is confirmed by demonstration of a deficient aCDase activity and the subsequent storage of ceramide. Existing methods include extremely complex assays, many of them using radiolabeled compounds. Therefore, the aCDase assay and the in vitro enzymatic diagnosis of FD are still performed in only a very limited number of specialized laboratories. Here, the new fluorogenic substrate Rbm14-12 was synthesized and characterized as a new tool to determine aCDase activity. The resulting optimized assay was performed in 96-well plates, and different fibroblast and lymphoid cell lines derived from FD patients and controls were tested to measure aCDase activity. As a result, the activity in cells of FD patients was found to be very low or even null. This new fluorogenic method offers a very easy and rapid way for specific and accurate determination of aCDase activity and, consequently, for diagnosis of FD.

Efecto del Rituximab sobre los niveles circulantes de citocinas y quimiocinas producidas o no por los linfocitos B en pacientes con Artritis Reumatoide

La Artritis Reumatoide (AR) es una enfermedad autoinmune frecuente, caracterizada por inflamación crónica en las articulaciones que puede progresar a la destrucción ósea. Aunque la fisiopatología de la AR no es clara, se ha visto que las células T y las células B desempeñan un importante papel en la misma. Estudios con Rituximab (RTX), un fármaco que elimina las células B CD20+, han contribuido a esclarecer y destacar la participación de las células B en la AR. Las células B pueden contribuir a la autoinmunidad de manera dependiente de la producción de los anticuerpos e independiente de esta producción. Esta última función puede ser debida al papel de las células B como presentadoras de antígeno para las células T y productoras de citocinas y quimiocinas. Para contribuir a entender este último mecanismo, se revisaron los artículos donde se evidenciaron los efectos del tratamiento con RTX sobre la citocinas y quimiocinas circulantes en pacientes con AR. Se encontró que la mayoría de las citocinas estudiadas disminuyeron sus niveles en circulación luego del tratamiento con RTX. La IL-10 y la IL-6 se vieron consistentemente disminuidas en los pacientes que respondieron al tratamiento y podrían ser marcadores del tratamiento con Rituximab.

Summary Rheumatoid Arthritis (RA) is a common autoimmune disease characterized by chronic inflammation in the joints that can progress to bone destruction. Although the pathophysiology of RA is unclear, T cells and B cells are though to be involved. Rituximab (RTX), a drug that eliminates CD20 + B cells, has helped to clarify and highlight the role of B cells in RA. B cells can contribute to autoimmunity by mechanisms dependent on the production of antibodies and independent of this production. The latter may depend on the role of B cells as antigen-presenting cells for T cells and their capacity to produce cytokines and chemokines. To contribute to our understanding of this mechanism, studies that evaluated levels of circulating cytokines and chemokines in patients with RA after treatment with RTX were reviewed. Most cytokines studied decreased their levels in circulation after treatment with RTX. IL-10 and IL-6 consistently were decreased in patients responding to treatment and maybe markers of Rituximab treatment.

Comparison of Plasma Cytokine Levels before and after Treatment with Rituximab in Patients with Rheumatoid Arthritis and Systemic Lupus Erythematosus-Associated Polyautoimmunity / Comparación de citocinas plasmáticas antes y después del tratamiento con rituximab en pacientes con artritis reumatoide y lupus eritematoso sistémico asociado a poliautoinmunidad

Introducción: La coexistencia de más de una enfermedad autoinmune (EAI) en un paciente se conoce como poliautoinmunidad (PAI) y se observa en el 35% de los pacientes con EAI. La eliminación de linfocitos B usando rituximab (RTX) controla la actividad de diferentes EAI. En el lupus eritematoso sistémico (LES) y en PAI no es clara la producción de citocinas por los linfocitos B. Métodos: Estudio exploratorio. Se obtuvo plasma de 11 pacientes con artritis reumatoide (AR) y poliautoinmunidad asociada a LES (PAILES) antes y después de rituximab (i. e., 6 meses). Como controles se utilizaron ocho individuos sanos. Las citocinas se midieron por ELISA (IFN-a, TGF-pl) o Cytometnc Bead Array (TNF-a, IL-ip, IL-ó, IL-8, IL-10, IL-12p7O). Resultados: Previo a RTX, IL-ó se encontró elevada únicamente en AR, mientras que IL-8 lo estuvo en AR y en PAILES, comparados con controles. Después de RTX se encontró una disminución significativa de IL-ó en AR y de IL-8 en PAILES. Las concentraciones de otras citocinas medidas fueron similares (IFN-a, TGF-B1) o se encontraron por debajo de límite de detección (TNF-a, IL-1[3, IL-10, IL-12p7O), tanto en pacientes como en controles. Conclusión: Los datos resaltan la importancia de la secreción de citocinas por los linfocitos B y sugieren un rol diferencial en cada patología. El incremento de IL-8 previo a RTX en ambos grupos y la reducción después de la terapia en PAILES respaldan el potencial de la IL-8 como objetivo terapéutico. La heterogeneidad de la población de pacientes con PAI reafirma la importancia de la selección de subgrupos específicos en estudios futuros.

Introduction: Coexistence of more than one autoimmune disease (AD) in a single patient is known as polyautoimmunity, and may be seen in up to 35% of patients with ADs. The elimination of B-cells using Rituximab (RTX) improves clinical status in different ADs. The role of cytokine production by B-cells is unclear in systemic lupus erythematosus (SLE) and polyautoimmunity. Methods: As an exploratory study, plasma from 11 patients with either rheumatoid arthritis (RA) or SLE-associated polyautoimmunity was assessed prior and 6 months after therapy with RTX. Eight healthy individuáis were used as Controls. Cytokine levels were measured using ELISA (IFN-a and TGF-61) or Cytometric Bead Array (TNF-a, IL-1

Determination of sphingosine-1-phosphate lyase activity by gas chromatography coupled to electron impact mass spectrometry.

Sphingosine-1-phosphate lyase (SGPL1) is the last enzyme in the catabolism of sphingolipids. It catalyzes the retroaldolic cleavage of long chain base phosphates into phosphoethanolamine and a fatty aldehyde. In this article we report on an easy and sensitive procedure to determine SPL activity. The assays uses C17-sphinganine-1-phosphate as substrate and the aldehyde product, pentadecanal, is quantified as its pentafluorobenzyloxime derivative by GC/MS. Derivatization of pentadecanal is performed as a one-step reaction, and the oxime product is directly injected for GC/MS analysis without any further purification. Acquisition in selected ion monitoring mode allows very high sensitivity, with a limit of detection of 281fmol. The assay is linear with both protein concentration and incubation time up to 20µg and 40min, respectively. The K(m) value obtained (6µM) is similar to that for the natural substrate sphingosine-1-phosphate. Using this method, FTY720 and deoxypyridoxine phosphate inhibited SPL with similar potencies to those reported.

Control of metabolism and signaling of simple bioactive sphingolipids: Implications in disease.

Simple bioactive sphingolipids include ceramide, sphingosine and their phosphorylated forms sphingosine 1-phosphate and ceramide 1-phosphate. These molecules are crucial regulators of cell functions. In particular, they play important roles in the regulation of angiogenesis, apoptosis, cell proliferation, differentiation, migration, and inflammation. Decoding the mechanisms by which these cellular functions are regulated requires detailed understanding of the signaling pathways that are implicated in these processes. Most importantly, the development of inhibitors of the enzymes involved in their metabolism may be crucial for establishing new therapeutic strategies for treatment of disease.