Response In Experimental Model Research Articles

Preventive and Therapeutic Effects of Lactiplantibacillus plantarum HD02 and MD159 through Mast Cell Degranulation Inhibition in Mouse Models of Atopic Dermatitis.

As the relationship between the gut microbiome and allergies becomes better understood, targeted strategies to prevent and treat allergies through gut microbiome modulation are being increasingly developed. In the study presented herein, we screened various probiotics for their ability to inhibit mast cell degranulation and identified Lactiplatibacillus plantarum HD02 and MD159 as effective candidates. The two strains significantly attenuated vascular permeability induced by mast cell degranulation in a passive cutaneous anaphylaxis (PCA) model and, in the MC903-induced murine atopic dermatitis (AD) model, demonstrated comparable preventive effects against allergies, reducing blood levels of MCPT-1 (mast cell protease-1) and total IgE. In the house dust mite (HDM)-induced murine AD model, both L. plantarum HD02 and MD159 showed therapeutic effects, with L. plantarum HD02 demonstrating superior efficacy. Nevertheless, L. plantarum MD159 better suppressed transepidermal water loss (TEWL). Furthermore, L. plantarum HD02 and MD159 significantly increased the number of splenic Foxp3+ regulatory T cells, with L. plantarum MD159 having a more pronounced effect. However, only L. plantarum HD02 achieved a reduction in immune cells in the draining lymph nodes. Our findings highlight L. plantarum HD02 and MD159 as promising candidates for the prevention and treatment of allergies, demonstrating significant efficacy in suppressing mast cell degranulation, reducing the number of allergy biomarkers, and modulating immune responses in experimental models of AD. Their distinct mechanisms of action suggest potential complementary roles in addressing allergic diseases, underscoring their therapeutic promise in clinical applications.

Antiarthritic and Antinociceptive Properties of Ylang-Ylang (Cananga odorata) Essential Oil in Experimental Models.

The aim of this study was to evaluate the effect of ylang-ylang (Cananga odorata) essential oil (YEO) on models of experimental arthritis, persistent inflammation, and nociception in mice. YEO treatment at doses of 100 and 200 mg/kg reduced the infiltration of leukocytes into the joint cavities of mice submitted to zymosan-induced arthritis 6 h and 7 days after arthritis induction. At these doses, YEO treatment reduced the formation of joint edema 4 and 6 h after arthritis induction, and at a dose of 200 mg/kg, YEO treatment reduced mechanical hyperalgesia 3 and 4 h after arthritis induction. At the dose of 200 mg/kg, YEO treatment reduced interleukin-6 (IL-6) levels and cartilage destruction in the zymosan-induced arthritis model, and reduced edema formation and mechanical hyperalgesia in the model of persistent inflammation (21 days) induced by complete Freund's adjuvant (CFA) in mice. YEO treatment at a dose of 200 mg/kg reduced the nociceptive response in experimental models of nociception induced by acetic acid and formalin. The YEO treatment reduced inflammatory parameters in the experimental arthritis model, and presented antiarthritic, anti-hyperalgesic, antinociceptive, and anti-inflammatory properties.

Aerobic and Resistant Physical Exercise on Chronic Kidney Disease (CKD) Patients: are there any Benefits?

Chronic kidney disease (CKD) has become an epidemic condition, with increasing incidence worldwide, generating high mortality rates and high health care costs. Several studies have demonstrated that inflammation is common in patients with CKD and it is associated with a high mortality rate in this population. Regular exercise has been described as a therapeutic strategy for reducing the risk of chronic and metabolic diseases, in part because of exercise training seems to exert anti-inflammatory effects. Therefore, the aim of the present review was to analyze the effects of aerobic and resistance exercise on inflammatory biomarkers in patients with CKD. CKD results in serum accumulation of toxic substances, the uremic toxins. These activate immune and inflammatory response in experimental models and in patients with CKD. Several studies involving non-pharmacological interventions have focused on CKD patients, aiming at reducing the inflammatory state, improving quality of life and extending the survival of these patients. It has been found that using treadmill for walking in patients undergoing pre-dialysis treatment was effective in reducing CRP and IL-6, showing that this type of aerobic exercise may also promote an anti-inflammatory effect. In contrast, some studies have not been able to show any beneficial effect on inflammation; e.g., a study using an intradialytic cycling protocol for HD patients 3x / week for 6 months found no decrease in IL-6, CRP and TNF-α. There are a number studies reporting favorable effects of exercise training on the inflammatory response triggered by hypertension, diabetes, obesity, dyslipidemia and cardiovascular events in the general population; however, this review showed that the role of the anti-inflammatory effect of aerobic and resistance exercise remains controversial in CKD patients, particularly in those undergoing dialysis. Conversely, data from the literature found that high intensity aerobic exercise training for a sustained period of time seems to have anti-inflammatory effects when compared to resistance exercise, in particular when PCR is used as a marker of inflammation.

Vitamin D supplementation attenuates acute inflammatory response

This study evaluated the effects of daily vitamin D supplementation on the acute inflammatory response in experimental model by different phlogistic agents: carrageenan, prostaglandin and dextran. Animals (rats) orally received (gavage) a single dose of vitamin D or daily supplementation for 7, 15 or 30 days prior to paw edema induced. Vitamin D supplementation for 15 and 30 days significantly reduced the carrageenan-induced inflammatory process, which could be at least partially explained by the reduction of tumor necrosis factor α levels (TNFα). Results indicate that vitamin D supplementation may be a useful therapeutic adjuvant for controlling the acute inflammatory process.

Nitro-oleic acid, a ligand of CD36, reduces cholesterol accumulation by modulating oxidized-LDL uptake and cholesterol efflux in RAW264.7 macrophages

Macrophages play a pivotal role in the early stages of atherosclerosis development; they excessively accumulate cholesterol in the cytosol in response to modified Low Density Lipoprotein (mLDL). The mLDL are incorporated through scavenger receptors. CD36 is a high-affinity cell surface scavenger receptor that facilitates the binding and uptake of long-chain fatty acids and mLDL into the cell. Numerous structurally diverse ligands can initiate signaling responses through CD36 to regulate cell metabolism, migration, and angiogenesis. Nitro-fatty acids are endogenous electrophilic lipid mediators that react with and modulate the function of multiple enzymes and transcriptional regulatory proteins. These actions induce the expression of several anti-inflammatory and cytoprotective genes and limit pathologic responses in experimental models of atherosclerosis, cardiac ischemia/reperfusion, and inflammatory diseases. Pharmacological and genetic approaches were used to explore the actions of nitro-oleic acid (NO2-OA) on macrophage lipid metabolism. Pure synthetic NO2-OA dose-dependently increased CD36 expression in RAW264.7 macrophages and this up-regulation was abrogated in BMDM from Nrf2-KO mice. Ligand binding analysis revealed that NO2-OA specifically interacts with CD36, thus limiting the binding and uptake of mLDL. Docking analysis shows that NO2-OA establishes a low binding energy interaction with the alpha helix containing Lys164 in CD36. NO2-OA also restored autophagy flux in mLDL-loaded macrophages, thus reversing cholesterol deposition within the cell. In aggregate, these results indicate that NO2-OA reduces cholesterol uptake by binding to CD36 and increases cholesterol efflux by restoring autophagy.

Effect of baseline medications on response to immunotherapy in hepatocellular carcinoma.

484 Background: Immunotherapy (IO) response rates in advanced hepatocellular carcinoma (HCC) are less than 20%. The microbiome has been shown to mediate IO response in experimental models, and clinical studies have observed that antibiotics, especially prior to IO initiation, are associated with reduced IO response. We reasoned that commonly prescribed antacid medications, such as proton pump inhibitors (PPIs) and histamine receptor antagonists (H2RAs), which are known to influence the microbiome, may also influence IO response. Methods: This is a retrospective chart review-based study of 95 patients with advanced HCC treated with IO at a single academic medical center. The primary outcome was overall survival (OS). The secondary outcome was overall response rate (ORR). The primary predictors were antibiotic or antacid exposure in the 60 days prior to IO. A secondary predictor was antibiotic or antacid exposure in the 30 days prior to IO. Results: The cohort was predominantly male (84%), was racially diverse (31% White, 23% Black, 23% Asian, 13% Hispanic), and had a median age of 65 years. There were 49 deaths with a median follow up of 0.96 years. The most common underlying liver diseases were HCV (49%), HBV (31%), and NASH (11%). The majority of patients had cirrhosis (80%), with a median Child Pugh score of 6. Within 60 days before IO, 25 patients received antibiotics, 40 received PPIs and 5 received H2RAs. Most patients receiving antibiotics also received a PPI (92%). The median duration of antibiotics was 5 days. Neither antibiotic nor antacid exposure within 60 or 30 days prior to IO was significantly correlated with OS in univariate or multivariate analyses, nor were they correlated with ORR. Conclusions: No significant associations between baseline exposure to antibiotics and antibiotics and OS or ORR were identified in this single-institution study. Larger observational studies or mechanistic studies are needed to clarify interactions between medications, the microbiome, and IO response. [Table: see text]

Ginsenoside metabolite 20(S)-protopanaxatriol from Panax ginseng attenuates inflammation-mediated NLRP3 inflammasome activation.

Panax ginseng C.A. Meyer (Araliaceae), has been used in traditional medicine for preventive and therapeutic purposes in Asian countries. One of the active ginsenoside metabolites, 20(S)-Protopanaxatriol (PPT), has been associated with diverse pharmacological effects, including anti-inflammatory properties. Although the capacity of PPT as an anti-inflammatory agent has been studied, this study aimed to explore the intrinsic mechanism of PPT in regulating inflammasome activation-mediated inflammatory responses in experimental models. Lipopolysaccharide (LPS)-primed peritoneal macrophages in vitro was used to study the role of PPT on inflammasome activation. LPS-induced septic shock and monosodium urate (MSU)-induced murine peritonitis models were employed for in vivo evaluations. PPT attenuated NLRP3 inflammasome activation and also reduced ASC oligomerization, leading to attenuation of interleukin (IL)-1β secretion. Further, PPT inhibited IL-1β secretion in both LPS-induced septic shock and MSU-induced mouse peritonitis models. This study revealed that ginsenoside metabolite PPT, inhibits inflammation-mediated inflammasome activation and supported the traditional use of ginseng in treating various inflammatory disorders.

Apigenin Decreases Acinar Cell Damage in Pancreatitis.

Chronic pancreatitis is the consequence of multiple episodes of recurrent acute pancreatitis (RAP). We hypothesized that apigenin can minimize the sequelae of RAP by limiting acinar cells' proinflammatory signaling pathways. AR42J acinar cells were treated in vitro with transforming growth factor β (TGF-β), apigenin, and other inhibitors. Dual luciferase reporter assay measured parathyroid hormone-related protein (PTHrP) promoter activity. MAPK/ERK pathway activity was assessed by immunoblotting and in vivo by immunohistochemistry with a cerulein-induced RAP mouse model. Nuclear factor κ B nuclear localization was analyzed in vitro in cells stimulated with tumor necrosis factor α. Primary acini were isolated and treated with cerulein; interleukin 6 messenger RNA was measured comparing PTHrP wild-type and knockout mice. Apigenin and PD98059 each downregulated TGF-β stimulation of PTHrP P3 promoter activity. In a RAP mouse model, apigenin reduced pERK nuclear localization in acinar cells and preserved acinar cell architecture. Apigenin suppressed tumor necrosis factor α-mediated signaling by decreasing nuclear factor κ B nuclear localization and decreased interleukin 6 messenger RNA levels via a PTHrP-dependent mechanism. Apigenin reduced inflammatory responses in experimental models of RAP. The mechanisms mediating the actions of apigenin, in part, are owing to attenuation of PTHrP and TGF-β proinflammatory signaling.

Development of an Interleukin-12 Fusion Protein That Is Activated by Cleavage with Matrix Metalloproteinase 9.

Interleukin-12 (IL-12) is a pleiotropic cytokine that has profound effects on many aspects of cell-mediated responses and can enhance antitumor responses in experimental models. IL-12 has been tested clinically, however, side-effects have limited its use. We are developing an attenuated form of IL-12 whose biological activity could be restricted to sites of tumors by taking advantage of overexpressed tumor proteases that can activate the cytokine. We constructed a panel of fusion proteins (FPs) consisting of IL-12 joined to a specific inhibitor connected by a protease cleavage sequence (cs). We first identified a panel of single-chain Fragment variable (scFv) that bind to 3 independent epitopes on IL-12 and then incorporated them into separate IL-12 FPs containing either a matrix metalloproteinase (MMP) cs or a scrambled (scram) control cs. The intact IL-12 FPs showed attenuation in IL-12 activity compared to free IL-12 in 2 separate in vitro functional assays; proliferation of CTLL-2 and interferon-gamma (IFN-γ) induction by spleen cells. Furthermore, the FP containing the MMPcs showed an increase in biological activity of IL-12 in vitro when cleaved by MMP9. This FP strategy could be applied to other immunomodulators and potentially reduce unwanted side-effects observed with systemic delivery thus improving cytokine immunotherapy strategies.

Impact of Bacille Calmette-Guérin revaccination on serum IgE levels in a randomized controlled trial.

Bacille Calmette-Guérin (BCG) downmodulates allergen-specific IgE levels and prevents other atopic responses in experimental models but fails to protect against respiratory allergies. Human responsiveness to BCG is variable and may interfere with protection. Multivariate models were evaluated to test the possible effect of responsiveness (assessed by IFN-γ production) to BCG revaccination on the modulation of total and allergen-specific serum IgE levels in healthy volunteers participating in a randomized controlled trial. Serum total or Derp-specific IgE levels did not change regardless of the increase in IFN-γ levels. BCG responsiveness does not affect protection against atopy.

Beneficial effects of combination of tissue transglutaminase inhibitor and interleukin-15 inhibitor in ameliorating mucosal immune inflammatory response in experimental model of Celiac Disease

Beneficial effects of combination of tissue transglutaminase inhibitor and interleukin-15 inhibitor in ameliorating mucosal immune inflammatory response in experimental model of Celiac Disease

Preliminary flagellin gene transfection into tumor cells - attempts of generating anti-tumor response in experimental model

Preliminary flagellin gene transfection into tumor cells - attempts of generating anti-tumor response in experimental model

Engineering Specificity and Function of Therapeutic Regulatory T Cells.

Adoptive therapy with polyclonal regulatory T cells (Tregs) has shown efficacy in suppressing detrimental immune responses in experimental models of autoimmunity and transplantation. The lack of specificity is a potential limitation of Treg therapy, as studies in mice have demonstrated that specificity can enhance the therapeutic potency of Treg. We will discuss that vectors encoding T cell receptors or chimeric antigen receptors provide an efficient gene-transfer platform to reliably produce Tregs of defined antigen specificity, thus overcoming the considerable difficulties of isolating low-frequency, antigen-specific cells that may be present in the natural Treg repertoire. The recent observations that Tregs can polarize into distinct lineages similar to the Th1, Th2, and Th17 subsets described for conventional T helper cells raise the possibility that Th1-, Th2-, and Th17-driven pathology may require matching Treg subsets for optimal therapeutic efficacy. In the future, genetic engineering may serve not only to enforce FoxP3 expression and a stable Treg phenotype but it may also enable the expression of particular transcription factors that drive differentiation into defined Treg subsets. Together, established and recently developed gene transfer and editing tools provide exciting opportunities to produce tailor-made antigen-specific Treg products with defined functional activities.

Role of Rifampin in Reducing Inflammation and Neuronal Damage in Childhood Bacterial Meningitis: A Pilot Randomized Controlled Trial.

Treatment of acute bacterial meningitis in children with bactericidal antibiotics causes cell wall lysis and a surge in inflammatory cascade, which in turn contributes to neuronal damage and morbidity. Pretreatment with a nonbacteriolytic antibiotic, such as rifampin, has been shown to attenuate the inflammatory response in experimental models of bacterial meningitis. In a pilot study, in children with bacterial meningitis, we have studied markers of inflammatory response and neuronal damage in 2 groups of children with bacterial meningitis; one group received rifampin pretreatment with ceftriaxone and the other group received ceftriaxone alone. Forty children with bacterial meningitis, who were 3 months to 12 years of age, were randomly assigned to receive either a single dose rifampin (20 mg/kg) 30 minutes before ceftriaxone or ceftriaxone alone was given. The primary outcome variables were cerebrospinal fluid (CSF) concentrations of tumor necrosis factor alpha (TNFα), S100B and neuron-specific enolase on day 1 and day 5, and secondary outcome variables were the values of TNFα and interleukin 6 in serum on day 1 and day 5; hearing and neurologic sequelae at 3 months after recovery from the illness. Children in rifampin pretreatment group had significantly lower CSF TNFα concentrations [median (interquartile range [IQR]): 15.5 (7.2-22.0) vs. 53.0 (9.0-87.5) pg/mL, P = 0.019] and S100B [median (IQR): 145.0 (54.7-450.0) vs. 447.5 (221.0-804.6) pg/mL, P = 0.033] on day 1 and S100B [median (IQR): 109.7 (64.0-287.0) vs. 322 (106.7-578.0) pg/mL, P = 0.048] and neuron-specific enolase [median (IQR): 8.6 (5-14.75) vs. 18.2 (7.0-28.75) ng/mL, P = 0.035] on day 5 when compared with ceftriaxone alone group. The rifampin-treated group also had reduced morbidity and neurologic sequelae; however, these were not statistically significant. Pretreatment with single dose rifampin 30 minutes before ceftriaxone administration reduced the CSF concentrations of markers of inflammation and neuronal damage in children with bacterial meningitis.

Early Phase Mast Cell Activation Determines the Chronic Outcome of Renal Ischemia-Reperfusion Injury.

Ischemia-reperfusion injury (IRI) is an important cause of acute kidney injury that can lead to end-stage renal failure. Although the ensuing inflammatory response can restore homeostasis, a consecutive maladaptive repair and persistent inflammation represent important risk factors for postischemic chronic kidney disease development. In this study, we investigated the role of mast cells in both the early and late phases of the inflammatory response in experimental models of acute and chronic renal IRI using our recently developed mouse model that allows conditional ablation of mast cells. Depletion of mast cells prior to IRI resulted in improved renal function due to diminished local inflammatory cytokine/chemokine levels and neutrophil recruitment to the kidneys after the acute injury phase (48 h post-IRI). Furthermore, although not completely protected, mast cell-depleted mice displayed less organ atrophy and fibrosis than did wild-type mice during the chronic phases (2 and 6 wk post-IRI) of disease development. Conversely, mast cell ablation after the acute phase of IRI had no impact on organ atrophy, tubular necrosis, or fibrosis. Thus, our results suggest a deleterious role of mast cells during the acute inflammatory phase of IRI promoting subsequent fibrosis development, but not during the chronic phase of the disease.

In Silico Adjuvant Design and Validation.

Adjuvants are substances that boost the protective immune response to vaccine antigens. The majority of known adjuvants have been identified through the use of empirical approaches. Our aim was to identify novel adjuvants with well-defined cellular and molecular mechanisms by combining a knowledge of immunoregulatory mechanisms with an in silico approach. CD4+CD25+FoxP3+ regulatory T cells (Tregs) inhibit the protective immune responses to vaccines by suppressing the activation of antigen presenting cells such as dendritic cells (DCs). In this chapter, we describe the identification and functional validation of small molecule antagonists to CCR4, a chemokine receptor expressed on Tregs. The CCR4 binds the chemokines CCL22 and CCL17 that are produced in large amounts by activated innate cells including DCs. In silico identified small molecule CCR4 antagonists inhibited the migration of Tregs both in vitro and in vivo and when combined with vaccine antigens, significantly enhanced protective immune responses in experimental models.

The role of peptides in bone healing and regeneration: a systematic review.

BackgroundBone tissue engineering and the research surrounding peptides has expanded significantly over the last few decades. Several peptides have been shown to support and stimulate the bone healing response and have been proposed as therapeutic vehicles for clinical use. The aim of this comprehensive review is to present the clinical and experimental studies analysing the potential role of peptides for bone healing and bone regeneration.MethodsA systematic review according to PRISMA guidelines was conducted. Articles presenting peptides capable of exerting an upregulatory effect on osteoprogenitor cells and bone healing were included in the study.ResultsBased on the available literature, a significant amount of experimental in vitro and in vivo evidence exists. Several peptides were found to upregulate the bone healing response in experimental models and could act as potential candidates for future clinical applications. However, from the available peptides that reached the level of clinical trials, the presented results are limited.ConclusionFurther research is desirable to shed more light into the processes governing the osteoprogenitor cellular responses. With further advances in the field of biomimetic materials and scaffolds, new treatment modalities for bone repair will emerge.

Molecular Components of the Sporothrix schenckii Complex that InduceImmune Response.

Sporotrichosis is a fungal disease caused by the Sporothrix schenckii complex that includes species such as S. brasiliensis, S. schenckii sensu stricto, S. globosa, S. luriei, S. mexicana, and S. pallida, which exhibit different potentially antigenic molecular components. The immune response of susceptible hosts to control infection and disease caused by these fungi has been little studied. Besides, the fungus-host interaction induces the activation of different types of immune response. This mini-review analyzes and discusses existing reports on the identification and functional characterization of molecules from species of the S. schenckii complex with clinical relevance, and the mechanisms that mediate the type and magnitude of the immune response in experimental models in vivo and in vitro. This knowledge is expected to contribute to the development of protective and therapeutic strategies against sporotrichosis and other mycoses.

Active opioid use does not attenuate the humoral responses to inactivated influenza vaccine

BackgroundInfluenza vaccination is recommended for vulnerable individuals, including active drug users, to prevent influenza complications and decrease influenza spread. Recent studies suggest that opioids negatively regulate immune responses in experimental models, but the extent to which opioid use will affect the humoral responses to influenza vaccine in humans is unknown. This information is critical in maximizing vaccination efforts. ObjectiveTo determine whether there is a difference in antibody response after influenza vaccination in heroin or methadone users compared to control subjects. MethodsWe studied active heroin users, subjects on methadone maintenance treatment (MMT) and subjects that did not use any drugs before and 1 and 4 weeks after vaccination with trivalent influenza vaccine (TIV). We measured hemagglutination inhibition and microneutralization titers, and we compared geometric mean titers (GMT), and rates of seroprotection and seroconversion for each of the vaccine strains among the 3 groups of subjects. ResultsHeroin users, subjects on MMT and non-user controls mount a similarly robust serologic response to TIV. GMT and rates of seroprotection and seroconversion were not significantly different among groups. ConclusionOur results suggest that opioid use do not significantly alter antibody responses to influenza vaccine supporting the vaccination effort in these populations.

Maintaining Balance Under Pressure: Integrated Regulation of Renal Transporters During Hypertension.

Hypertension is the leading cause of stroke and cardiovascular diseases and a leading risk factor for global disease burden, affecting 30% of the adult population in Western cultures.1 Blood pressure (BP) can be elevated by vasoconstriction and by increasing the circulating volume. Evidence from studies of mutations in renal Na+ transporters, renal transplantation, and diuretic action supports Guyton’s hypothesis that long-term regulation of effective circulating volume and BP depends on fractional renal Na+ reabsorption.2–4 Ultimately, excess Na+ reabsorption (Figure, red arrows) raises effective circulating volume and BP which provoke counteracting natriuretic responses to match Na+ output to Na+ intake at the expense of elevated BP (Figure, blue arrow).2 We and others have determined that pressure natriuresis responses involve Na+ transporter inhibition at multiple levels of regulation.5–13 According to Guyton, kidneys possess the capacity to excrete enough Na+ and volume to normalize BP in the face of expanded effective circulating volume.2 Thus, hypertension can be characterized as a failure of compensatory renal pressure natriuresis. Indeed, there is strong evidence that the pressure natriuresis response is impaired during experimental hypertension by inflammation, immune cell infiltration, and intrarenal angiotensin II (AngII) production, secondary to initiating stimuli such as AngII infusion, reduced NO production, high-salt diet, or elevated renal sympathetic nerve activity.14–17 This brief review focuses on the natriuretic effectors and addresses (1) the renal tubular locations and transporters that participate in pressure natriuresis and (2) the mechanisms that blunt the response in experimental models of hypertension. Figure. Renal transporter profile reveals region specific transporter regulation during experimental hypertension. A , Anatomic arrangement of renal cortex and renal medulla in a kidney cross-section …