Environmental effects of a management method used after fire on development of temperate Scots pine ecosystem: a 15-year study from Poland.

Due to the ongoing climate changes, temperate forests are increasingly exposed to fires. However, until now the functioning of post-fire temperate forest ecosystems with regard to used forest management method has been weakly recognized. Here, we examined three variants of forest restoration after fire (two variants of natural regeneration with no soil preparation-NR, and artificial restoration by planting following soil preparation-AR) regarding their environmental consequences in development of post-fire Scots pine (Pinus sylvestris) ecosystem. The study was conducted using a 15-year timespan in a long-term research site located in the Cierpiszewo area (N Poland) being one of the biggest post-fire grounds in European temperate forests in last decades. We focused on soil and microclimatic variables as well as on growth dynamics of post-fire pines generation. We found that the restoration rates of soil organic matter, carbon and most studied nutritional elements stocks were higher in NR plots than in AR. This could be primarily linked to the higher (p < 0.05) density of pines in naturally regenerated plots, and the subsequent faster organic horizon reconstruction after fire. The difference in tree density also involved regular differences in air and soil temperature among plots: consistently higher in AR than in both NR plots. In turn, lower water uptake by trees in AR implied that soil moisture was constantly the highest in this plot. Our study delivers strong arguments to pay more attention to restore post-fire forest areas with the use of natural regeneration with no soil preparation.

Monitoring the gold nanoshell growth mechanism: stabilizing and destabilizing effects of PEG-SH molecules.

Plasmonic nanoshells have attracted significant interest due to their resonant optical properties providing excellent spectral tunability, promising for various biophotonic applications. In this work we discuss our experimental and theoretical results related to the synthesis and optical characterization of surface-modified gold nanoshells. The nanoshell growth mechanism is monitored by IR spectroscopy, and the effects of modification of the gold nanoshell surface by PEG-SH ((11-mercaptoundecyl)tetra(ethylene glycol)) molecules are studied using TEM and optical methods. A red shift of localized surface plasmon resonance is observed upon formation of a layer of PEG-SH molecules on the completed gold nanoshells. Uncompleted gold shells show tendency to detach from the spherical silica cores, and the underlying destabilizing mechanism is discussed. The experimentally measured optical extinction properties are in good agreement with the results of numerical simulations, which additionally shed light on the localized plasmon modes contributing to the extinction, as well as on the effects of nanoshell surface nonuniformity on the resonant plasmonic properties and local field enhancements.

Apigenin and Hesperidin Downregulate DNA Repair Genes in MCF-7 Breast Cancer Cells and Augment Doxorubicin Toxicity.

A number of studies have confirmed anti-tumor activity of flavonoids and their ability to enhance the effectiveness of classical anticancer drugs. The mechanism of this phenomenon is difficult to explain because of the ambivalent nature of these compounds. Many therapeutic properties of these compounds are attributed to their antioxidant activity; however, it is known that they can act as oxidants. The aim of this study was to assess the influence of apigenin and hesperidin on MCF-7 breast cancer cells with doxorubicin. The cytotoxic effect was determined using an MTT test and cell cycle analysis. To evaluate the possible interaction mechanism, reduced glutathione levels, as well as the DNA oxidative damage and the double strand breaks, were evaluated. Additionally, mRNA expression of genes related to DNA repair was assessed. It was demonstrated that flavonoids intensified the cytotoxic effect of doxorubicin despite flavonoids reduced oxidative damage caused by the drug. At the same time, the number of double strand breaks significantly increased and expression of tested genes was downregulated. In conclusion, both apigenin and hesperidin enhance the cytotoxic effects of doxorubicin on breast cancer cells, and this phenomenon occurs regardless of oxidative stress but is accompanied by disorders of DNA damage response mechanisms.

Role of Obesogens in the Pathogenesis of Obesity.

Obesity is considered to be a 20th century pandemic, and its prevalence correlates with the increasing global pollution and the presence of chemical compounds in the environment. Excessive adiposity results from an imbalance between energy intake and expenditure, but it is not merely an effect of overeating and lack of physical activity. Recently, several compounds that alter the mechanisms responsible for energy homeostasis have been identified and called "obesogens". This work presents the role of obesogens in the pathogenesis of obesity. We reviewed data from in vitro animal and human studies concerning the role of obesogens in the disturbance of energy homeostasis. We identified (i) the main groups and classes of obesogens, (ii) the molecular mechanisms of their action, (iii) their deleterious effect on adipose tissue function and control of appetite, and (iv) possible directions in limiting their influence on human metabolism. Obesogens have a multifactorial detrimental influence on energy homeostasis. Focusing on limiting exposure to obesogens and improving early life nutrition seems to be the most reasonable direction of action to prevent obesity in future generations.

The development of orthography and phonology coupling in the ventral occipito-temporal cortex and its relation to reading.

The left ventral occipito-temporal (lvOT) cortex is considered to house the brain's representation of orthography (i.e., the spelling patterns of words). Because letter-sound coupling is crucial in reading, we investigated the engagement of the lvOT cortex in processing phonology (i.e., the sound patterns of words) as a function of reading acquisition. We tested 47 Polish children both at the beginning of formal literacy instruction and 2 years later. During functional magnetic resonance imaging, children performed auditory phonological tasks from small to large grain size levels (i.e., single phoneme, rhyme). We showed that orthographically relevant lvOT areas activated during small-grain size phonological tasks were skill-dependent, perhaps due to the relatively transparent mappings between orthography and phonology in Polish. We also studied activation pattern similarity between processing visual and auditory word stimuli in the lvOT. We found that a higher similarity level was observed in the anterior lvOT compared to the posterior lvOT after 2 years of schooling. This is consistent with models proposing a posterior-to-anterior shift in word processing during reading acquisition. We argue that the development of orthography-phonology coupling at the brain level reflects writing system-specific effects and a more universal pathway of the left vOT development in reading acquisition. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Liver Antioxidant Capacity and Steatosis in Laying Hens Exposed to Various Quantities of Lupin (Lupinus angustifolius) Seeds in the Diet.

Despite the many beneficial properties of legume plants, their use in diets for poultry is limited by the presence of antinutritional factors. The aim of the study was to determine the activity of DT-diaphorase, ethoxycoumarin O-deethylase, and catalase, and the concentration of malondialdehyde in liver tissue, as well as the activity of SOD and CAT in the serum of Hy-line Brown hens fed a diet supplemented with various doses of Lupinus angustifolius seeds. The results indicate that the use of large amounts of lupin in the diet resulted in an increase in MDA concentration in the liver and the lipid vacuolization of hepatocytes. A significant increase in DTD activity was observed in chickens receiving 15% lupin. Regardless of lupin dose, no increase in SOD activity was observed in chicken serum after 33 days of the experiment. From the 66th day of the experiment, an increase in catalase activity in the serum of laying hens was observed, while low activity of this enzyme was found in the liver. It can be concluded that the short-term use of lupin in the diet of laying hens does not affect the activity of antioxidant enzymes and, therefore, does not affect the oxidative-antioxidant balance of their body.

A Comparison Controlled Study Examining Outcome for Children With Autism Receiving Intensive Behavioral Intervention (IBI).

This study evaluated the effects of a center-based Intensive Behavioral Intervention (IBI) model for preschool aged children with autism. Outcomes of 25 children receiving IBI was compared to the outcomes of 14 children receiving autism specific, eclectic, special education. Both provisions were described as appropriate treatment options by the professional agency who diagnosed the children, and the decision of where to enroll the child was made by the parents after consultations with the specialists. After 14 months of treatment, children from the IBI group improved significantly on standard scores in intellectual functioning and adaptive behavior and had a significant reduction in autism severity compared to the children in the autism specific, eclectic, special education group. Results suggest that preschool aged children with autism may make large gains in intellectual and adaptive functioning and improvement in autism severity with IBI, and that effects of IBI may be similar to that of EIBI. These findings must be interpreted with caution due to the limitations inherent in the present comparison-controlled design.

Early reading skills and the ventral occipito-temporal cortex organization.

Learning to read impacts the way the ventral occipitotemporal cortex (VOT) reorganizes. The postulated underlying mechanism of neuronal recycling was recently revisited. Neuroimaging data showed that voxels weakly specialized for visual processing keep their initial category selectivity (i.e., object or face processing) while acquiring an additional and stronger responsivity to written words. Here, we examined a large and diverse group of six-year-olds prior to formal literacy training (N = 72) using various data analysis techniques (univariate, multivariate, rapid adaptation) and types of stimuli (print, false fonts, houses, faces) to further explore how VOT changes and adapts to the novel skill of reading. We found that among several visual stimuli categories only print activated a wide network of language related areas outside of the bilateral visual cortex, and the level of reading skill was related to the strength of this activation, showing the development of the reading circuit. Rapid adaptation was not directly related to the level of reading skill in the young children studied here, but it clearly revealed the emergence of the reading network in readers. Most importantly, we found that the reorganization of the VOT is not in fact an "invasion" by reading acquisition-voxels previously activated for faces started to respond more for print, while at the same time keeping their previous function. We can thus conclude that the revised hypothesis of neuronal recycling is supported by our data.

Beyond the Visual Word Form Area - a cognitive characterization of the left ventral occipitotemporal cortex.

The left ventral occipitotemporal cortex has been traditionally viewed as a pathway for visual object recognition including written letters and words. Its crucial role in reading was strengthened by the studies on the functionally localized "Visual Word Form Area" responsible for processing word-like information. However, in the past 20 years, empirical studies have challenged the assumptions of this brain region as processing exclusively visual or even orthographic stimuli. In this review, we aimed to present the development of understanding of the left ventral occipitotemporal cortex from the visually based letter area to the modality-independent symbolic language related region. We discuss theoretical and empirical research that includes orthographic, phonological, and semantic properties of language. Existing results showed that involvement of the left ventral occipitotemporal cortex is not limited to unimodal activity but also includes multimodal processes. The idea of the integrative nature of this region is supported by the broad functional and structural connectivity with language-related and attentional brain networks. We conclude that although the function of the area is not yet fully understood in human cognition, its role goes beyond visual word form processing. The left ventral occipitotemporal cortex seems to be crucial for combining higher-level language information with abstract forms that convey meaning independently of modality.

Third-Order Nonlinear Optical Properties of Aqueous Silver Sulfide Quantum Dots.

Wide spectral wavelength range (500-1600 nm) measurements of nonlinear optical properties of silver sulfide (Ag2S, with 2- or 3-mercaptopropionic acid, 2 or 3MPA ligands) quantum dots (QDs) in aqueous colloidal solutions were performed using the Z-scan technique with tunable ∼55 fs laser pulses at 1 kHz. We have identified regions of the occurrence of various NLO effects including two-photon absorption, nonlinear refraction, as well as saturation of one-photon absorption. At the same time, we evaluated the relationship between the properties of the QDs and the variation of the material that covers their surface. The peak two-photon absorption cross section (σ2) values were determined to be 632 ± 271 GM (at 850 nm) for Ag2S-2MPA QDs and 772 ± 100 GM (at 875 nm) for Ag2S-3MPA QDs. The physicochemical factors influencing the three-dimensional self-organization of Ag2S QDs in water as well as their impact on spectroscopic properties were also investigated.

COVID-19 mRNA BNT162b2 vaccine safety and B-cell and T-cell reactogenicity among children with a history of paediatric multisystem inflammatory syndrome temporally associated with COVID-19 (PIMS-TS) - preliminary study.

To assess the safety of Pfizer-BioNTech COVID-19 mRNA BNT162b2 vaccine (Comirnaty®) among patients with the anamnesis of paediatric inflammatory syndrome temporally associated with COVID-19 (PIMS-TS), we conducted a prospective cohort study of 21 patients with history of PIMS (PIMS group, median age 7.4 years, 71% male) and 71 healthy controls without such an anamnesis (CONTROL group, median age 9.0 years, 39% male) aged 5-18 years. Among them, 85 patients (all PIMS patients and 64 CONTROL patients) completed the two dose schedule of vaccination administered 21 days apart and 7 children in the CONTROL group received a single, age appropriate dose of a COVID-19 mRNA BNT162b2 vaccine during the study period. The frequency and character of reported adverse events (AEs) after each dose and results of flow cytometry (FC) 3 weeks after a second dose were compared between those groups. COVID-19 mRNA BNT162b2 vaccine safety profile was very good and comparable in both groups. No severe AEs were observed. 30% of all patients reported some general AE after any vaccine dose and 46% - some local AE. Frequency of reported AEs did not differ between groups except for local hardening at injection site, more common in PIMS group (20% vs 4% after any vaccine dose, p = 0,02). All AEs were benign, general AEs lasted up to 5 days and localised - up to 6 days after a vaccine dose. COVID-19 mRNA BNT162b2 vaccine did not induce any PIMS-like symptoms in any patient. We did not observe any significant T cells or B cells subset abnormalities in the PIMS group compared to the CONTROL group three weeks after a second dose except for terminally differentiated effector memory T cells that were higher in PIMS group (p < 0.0041). To sum up COVID-19 mRNA BNT162b2 vaccine in children with PIMS-TS was safe. Further studies are required to support our findings.

COVID-19 mRNA BNT162b2 vaccine immunogenicity among children with a history of paediatric multisystem inflammatory syndrome temporally associated with COVID-19 (PIMS-TS).

We conducted a prospective cohort study of 20 patients with a history of paediatric multisystem inflammatory syndrome temporally associated with COVID-19 (PIMS group, median age seven years, 70% male) and 34 healthy controls without such a history (CONTROL group, median age eight years, 38% male) aged 5-12 years, to assess the immunogenicity of Pfizer-BioNTech COVID-19 mRNA BNT162b2 vaccine (Comirnaty®). Patients received two doses of COVID-19 mRNA BNT162b2 vaccine (10 ug/dose) 21 days apart. Pre-vaccine anti-S SARS-CoV-2 IgG antibodies were measured on the day of the first dose and at the median of 23 days after the second dose. The study was conducted during the COVID-19 wave dominated by the Omicron variant of the virus. Anti-NCP SARS-CoV-2 IgG antibodies were measured twice to evaluate incidents of infection during the study period. Pre-vaccine quantification of both types of antibodies allowed us to differentiate patients into COVID-19 naive and previously infected in order to compare hybrid immunity with vaccine-induced immunity. Before vaccination, anti-S IgG serum geometric mean concentration (GMC) was 61.17 BAU/ml in the PIMS group and 24.97 in the CONTROL group, while post-vaccination GMC was 3879.14 BAU/ml and 3704.87 BAU/ml, respectively, and did not significantly differ between the groups. Hybrid immunity (regardless of PIMS history) resulted in a higher concentration of SARS-CoV-2 anti-S antibodies after vaccination. Four (20%) of the children in the PIMS group and 11 (32%) in the CONTROL group got infected with SARS-CoV-2 during the study period, yet all of them asymptomatically, and this event has not significantly altered post-vaccination anti-S titers. In conclusion, COVID-19 vaccination was highly immunogenic in children, including those with a history of PIMS-TS; hybrid immunity overperforms vaccine-induced immunity in terms of serological response in children. However, vaccination effectiveness in preventing SARS-CoV-2 infections in children should be further evaluated.

Immunodetection of cyclooxygenase-2 (COX-2) is restricted to tissue macrophages in normal rat liver and to recruited mononuclear phagocytes in liver injury and cholangiocarcinoma.

It has been suggested that cyclooxygenase-2 (COX-2)-mediated prostaglandin synthesis is associated with liver inflammation and carcinogenesis. The aim of this study is to identify the cellular source of COX-2 expression in different stages, from acute liver injury through liver fibrosis to cholangiocarcinoma (CC). We induced in rats acute and "chronic" liver injury (thioacetamide (TAA) or carbon tetrachloride (CCl(4))) and CC development (TAA) and assessed COX-2 gene expression in normal and damaged liver tissue by RT-PCR of total RNA. The cellular localization of COX-2 protein in liver tissue was analyzed by immunohistochemistry as well as in isolated rat liver cells by Western blotting. The findings were compared with those obtained in human cirrhotic liver tissue. The specificity of the antibodies was tested by 2-DE Western blot and mass spectrometric identification of the positive protein spots. RT-PCR analysis of total RNA revealed an increase of hepatic COX-2 gene expression in acutely as well as "chronically" damaged liver. COX-2-protein was detected in those ED1(+)/ED2(+) cells located in the non-damaged tissue (resident tissue macrophages). In addition COX-2 positivity in inflammatory mononuclear phagocytes (ED1(+)/ED2(-)), which were also present within the tumoral tissue was detected. COX-2 protein was clearly detectable in isolated Kupffer cells as well as (at lower level) in isolated "inflammatory" macrophages. Similar results were obtained in human cirrhotic liver. COX-2 protein is constitutively detectable in liver tissue macrophages. Inflammatory mononuclear phagocytes contribute to the increase of COX-2 gene expression in acute and chronic liver damage induced by different toxins and in the CC microenvironment.

Growth Rate and Bone Hydroxyproline Concentration in Turkeys Fed with a Silage-Composed Diet Modified with Different Diet Cation-Anion Differences (DCADs).

Our goal was to determine the responses of body weight (BW) and bone hydroxyproline (Hyp) concentration in turkeys fed a corn silage (CS) diet with different values of dietary cation-anion differences (DCADs). The turkeys (n = 90) were divided into five groups and fed as follows: group A (control)-standard diet (SD) (60%) plus CS (40%); group B-SD (60%), CS (40%) plus 240 g of CaCl2 per 100 kg of diet; group C-SD (60%), CS (40%) plus 480 g of CaCl2 per 100 kg of diet; group D-SD (60%), CS (40%) plus 240 g of NaHCO3 per 100 kg of diet; group E-SD (60%), CS (40%) plus 480 g NaHCO3 per 100 kg of diet. The addition of a lesser amount of CaCl2 lowered the DCAD, which ranged between 52.5 ± 4.19 and 91.14 ± 3.14 mEq/kg DM. An increased content of CaCl2 led to high negative values of DCAD. NaHCO3 supplemented in both doses resulted in a significant elevation of DCAD. Compared to each experimental group, feeding birds with a diet supplemented only with CS resulted in a lower BW. Addition of CaCl2 or NaHCO3 to the diet improved BW, but only CaCl2 addition enhanced the bone Hyp amount. In conclusion, we suggest that an anionic diet with low DCAD can prevent bone abnormalities in large turkeys, especially in the final course of production.

Alternative Materials for the Enrichment of Biogas with Methane.

Carbonaceous adsorbents have been pointed out as promising adsorbents for the recovery of methane from its mixture with carbon dioxide, including biogas. This is because of the fact that CO2 is more strongly adsorbed and also diffuses faster compared to methane in these materials. Therefore, the present study aimed to test alternative carbonaceous materials for the gas separation process with the purpose of enriching biogas in biomethane and to compare them with the commercial one. Among them was coconut shell activated carbon (AC) as the adsorbent derived from bio-waste, rubber tire pyrolysis char (RPC) as a by-product of waste utilization technology, and carbon molecular sieve (CMS) as the commercial material. The breakthrough experiments were conducted using two mixtures, a methane-rich mixture (consisting of 75% CH4 and 25% CO2) and a carbon dioxide-rich mixture (containing 25% CH4 and 75% CO2). This investigation showed that the AC sample would be a better candidate material for the CH4/CO2 separation using a fixed-bed adsorption column than the commercial CMS sample. It is worth mentioning that due to its poorly developed micropore structure, the RPC sample exhibited limited adsorption capacity for both compounds, particularly for CO2. However, it was observed that for the methane-rich mixture, it was possible to obtain an instantaneous concentration of around 93% CH4. This indicates that there is still much potential for the use of the RPC, but this raw material needs further treatment. The Yoon-Nelson model was used to predict breakthrough curves for the experimental data. The results show that the data for the AC were best fitted with this model.

Risk factors for infectious complications after retrograde intrarenal surgery - a systematic review and narrative synthesis.

INTRODUCTION: Infectious complications are among the most frequent and significant complications in retrograde intrarenal lithotripsy. To date, review articles have covered complications after a ureteroscopy, but not after retrograde intrarenal surgery (RIRS), specifically. Because the complications and risk factors are different for a ureteroscopy and RIRS, we aimed to identify variables related to the occurrence of infectious complications post-RIRS. MATERIAL AND METHODS: This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. We included original studies that described 100 or more procedures published in 2014-2021. We extracted data and performed a narrative synthesis to explore and interpret differences between the studies. RESULTS: We selected 17 studies for analysis, including 10 from 2019-2021. Infectious complications after RIRS were observed in 2.8-7.5% of patients (mean 7.1%). We found seven independent risk factors associated with infectious complications after RIRS: long operative time, recent history of positive urine culture or urinary tract infection or antibiotic use, pyuria/nitrites, small caliber of ureteral access sheath, struvite stone, high irrigation rate, and comorbidities. CONCLUSIONS: If an increased rate of infectious complications is found at a RIRS center, countermeasures should include restrictions on operative time and irrigation rate, and consideration of larger access sheaths, especially for patients with abnormal urine results or with struvite stones or with a history of urinary tract infection or co-morbidities.

The COVID-19 mRNA BNT163b2 Vaccine Was Well Tolerated and Highly Immunogenic in Young Adults in Long Follow-Up after Haematopoietic Stem Cell Transplantation.

Sixty five patients (18-31 years) who had received allogeneic haematopoietic stem cell transplantation (3-27 years from HSCT) were evaluated for the tolerance and immunogenicity of the COVID-19 mRNA BNT163b2 vaccine. Methods: Patients were vaccinated with two doses at 5 weeks interval. After each dose, patients completed a survey concerning adverse events (AE) and anti-SARS-CoV-2 IgG antibodies were measured before the first vaccine dose (1stVD) and 14-21 days after the second dose (2ndVD). AE reported after 1stVD and 2ndVD, respectively were: fever 0%, 1.7%; fatigue 15.4%, 25.8%; headache 15.4%, 24.1%; chills 6.1%, 12.0%; muscle pain 15.4%, 24.1%; joint pain 3.0%, 6.9%; nausea 6.1%, 6.9%; pain at injection site 30.7%, 34.4%; swelling 3.0%, 10.3%; redness 0, 3.4%; pruritus 0, 5.2%; and axillary lymphadenopathy 3.0%, 1.7%. After 2ndVD, 96.5% patients were positive for anti-SARS-CoV-2 (GMC 3290.94 BAU/mL). No correlation presented between the antibody titer and symptoms of chronic Graft-versus-Host disease, total IgG, lymphocyte CD4+, or AE. Significantly higher titers were observed in COVID-19 convalescents, and inverse correlation (R2 = -0.0925, p = 0.02) between the time from HSCT and titers after 2ndVD was present. Conclusions: The young adults after HSCT tolerate the COVID-19 mRNA vaccine well and show immunologic response.

When and how does the number of children affect marital satisfaction? An international survey.

The present global study attempts to verify the links between marital satisfaction and the number of children as well as its moderators in an international sample. Data for the study was obtained from our published dataset and included 7178 married individuals from 33 countries and territories. We found that the number of children was a significant negative predictor of marital satisfaction; also sex, education, and religiosity were interacting with the number of children and marital satisfaction, while there were no interactions with economic status and individual level of individualistic values. The main contribution of the present research is extending our knowledge on the relationship between marital satisfaction and the number of children in several, non-Western countries and territories.

Expression of receptor interacting protein 1 and receptor interacting protein 3 oval cells in a rat model of hepatocarcinogenesis.

When apoptosis is suppressed in a neoplastic state, necroptosis may enable an anticancer response. In the present study, the association between apoptosis and necroptosis was assessed in a partial hepatectomy (PH)/diethylnitrosamine (DEN) rat model of hepatocarcinogenesis. Isolated oval cells (OCs) were analysed at 24, 48 and 72 h and at the first and second week of incubation. Phenotypic studies, apoptosis and necroptosis detection and proliferative activity assays were also performed on the OCs. The OCs were isolated from non-neoplastic (PH) and neoplastic (PH/DEN) livers, which expressed receptor interacting protein (RIP) 1 and RIP3. Western blot analysis revealed that the RIP1 and RIP3 expression in the PH/DEN OCs started to increase at 72 h and continually increased to the end of cell culture. Compared with the PH OCs, the cells isolated from PH/DEN rats exhibited significantly less potential for apoptosis (P<0.05). There were a minimal number of apoptotic PH/DEN OCs (2.82±1.1%) at 72 h. In addition, the PH/DEN OCs demonstrated progressive proliferative activity during incubation, which was significantly increased compared with the PH OCs at ≥72 h. The present study revealed that PH/DEN OCs, which trigger hepatic cancer, have a high proliferative activity and suppress apoptosis. It was also observed that, based on the expression of RIP3 and RIP1, necroptosis may be maintained and may serve as an alternative pathway for programmed PH/DEN OC death.

Structure-Activity Relationship of Plesiomonas shigelloides Lipid A to the Production of TNF-α, IL-1ß, and IL-6 by Human and Murine Macrophages.

Plesiomonas shigelloides is a Gram-negative bacterium that is associated with diarrheal disease in humans. Lipopolysaccharide (LPS) is the main surface antigen and virulence factor of this bacterium. The lipid A (LA) moiety of LPS is the main region recognized by target cells of immune system. Here, we evaluated the biological activities of P. shigelloides LA for their abilities to induce the productions of proinflammatory cytokines (TNF-α, IL-1ß, and IL-6) by human and murine macrophages [THP-1 macrophages and immortalized murine bone marrow-derived macrophages (iBMDM)]. Four native P. shigelloides LA preparations differing in their phosphoethanolamine (PEtn) substitution, length, number, and saturation of fatty acids were compared with Escherichia coli O55 LA. The bisphosphorylated, hexaacylated, and asymmetric forms of the P. shigelloides and E. coli LA molecules had similar activities in human and murine macrophages, indicating that shortening of the acyl chains in P. shigelloides LA had no effect on its in vitro activities. The PEtn decoration also had no impact on the interaction with the toll-like receptor 4/MD-2 receptor complex. The heptaacylated form of P. shigelloides LA decorated with 16:0 exhibited strong effect on proinflammatory activity, significantly decreasing the levels of all tested cytokines in both murine and human macrophages. Our results revealed that despite the presence of shorter acyl chains and an unsaturated acyl residue (16:1), the bisphosphorylated, hexaacylated, and asymmetric forms of P. shigelloides LA represent highly immunostimulatory structures.