Density Of Inflammatory Cells Research Articles

Photocrosslinkable hydrogel of ibuprofen-chitosan methacrylate modulates inflammatory response.

Methacrylated biopolymers are unique and attractive in preparing photocrosslinkable hydrogels in biomedical applications. Here we report a novel chitosan (CS) derivative-based injectable hydrogel with anti-inflammatory capacity via methacrylation modification. First, ibuprofen (IBU) was conjugated to the backbone of CS by carbodiimide chemistry to obtain IBU-CS conjugate, which converts water-insoluble unmodified CS into water-soluble IBU-CS conjugate. The IBU-CS conjugate did not precipitate at the pH of 7, which was beneficial to subsequent chemical modification with methacrylic anhydride to prepare IBU-CS methacrylate (IBU-CS-MA) with significantly higher methacrylation substitution. Photocrosslinkable in situ gel formation of injectable IBU-CS-MA hydrogel was verified using lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) initiator under visible light. The IBU-CS-MA hydrogel showed good cytocompatibility as revealed by encapsulating and in vitro culturing murine fibroblasts within hydrogels. It promoted macrophage polarization toward M2 phenotype, as well as downregulated pro-inflammatory gene expression and upregulated anti-inflammatory gene expression of macrophages. The hydrogel also significantly reduced the reactive oxygen specifies (ROS) and nitrogen oxide (NO) produced by lipopolysaccharides (LPS)-stimulated macrophages. Upon subcutaneous implantation in a rat model, it significantly mitigated inflammatory responses as shown by significantly lower inflammatory cell density, less cell infiltration, and much thinner fibrous capsule compared with CS methacrylate (CS-MA) hydrogel. This study suggests that IBU-CS conjugate represents a feasible strategy for preparing CS-based methacrylate hydrogels for biomedical applications.

Evidence of the Role of Inflammation and the Hormonal Environment in the Pathogenesis of Adrenal Myelolipomas in Congenital Adrenal Hyperplasia.

Adrenal myelolipomas (AML) are composed of mature adipose and hematopoietic components. They represent approximately 3 percent of adrenal tumors and are commonly found in patients with congenital adrenal hyperplasia (CAH). CAH provides a unique environment to explore AML pathogenesis. We aimed to evaluate the role of the immune system and hormones that accumulate in poorly controlled CAH in the development of AML. When compared to normal adrenal tissue, CAH-affected adrenal tissue and myelolipomas showed an increased expression of inflammatory cells (CD68, IL2Rbeta), stem cells (CD117) B cells (IRF4), and adipogenic markers (aP2/FABP4, AdipoQ, PPARγ, Leptin, CideA), and immunostaining showed nodular lymphocytic accumulation. Immunohistochemistry staining revealed a higher density of inflammatory cells (CD20, CD3, CD68) in CAH compared to non-CAH myelolipomas. In vitro RNA-sequencing studies using NCI-H295R adrenocortical cells with exogenous exposure to ACTH, testosterone, and 17-hydroxyprogesterone hormones, showed the differential expression of genes involved in cell cycle progression, phosphorylation, and tumorigenesis. Migration of B-lymphocytes was initiated after the hormonal treatment of adrenocortical cells using the Boyden chamber chemotaxis assay, indicating a possible hormonal influence on triggering inflammation and the development of myelolipomas. These findings demonstrate the important role of inflammation and the hormonal milieu in the development of AML in CAH.

Mast cells in oral lichen planus and oral lichenoid lesions related to dental amalgam contact.

The aim of this study was to analyze the expression of mast cell markers toluidine blue, c-kit, and tryptase and presence of mononuclear inflammatory cells in oral lichen planus (OLP) and oral lichenoid lesions related to dental amalgam. Nineteen specimens of OLP, OLLC, and healthy oral mucosa were selected. Mononuclear inflammatory cells were analyzed. Histochemical and immunohistochemical analyses were performed using toluidine blue, anti-c-kit and anti-tryptase reagents, and the results were quantified in areas A and B of connective tissue. Mast cells of all OLP and OLLC samples were positive for toluidine blue, c-kit, and tryptase. The density of toluidine blue+, c-kit+ and tryptase+ mast cells was higher in tissue with OLP and OLLC compared with healthy controls (p < 0.05). No difference was noted in mast cells density between OLP and OLLC (p > 0.05). The density of tryptase+ mast cells was higher in the subepithelial region (area A) than the region below it (Area B) in OLLC (p = 0.047). The mononuclear inflammatory cell density was higher in OLLC compared to OLP, but without statistical significance (p > 0.05). A positive statistical correlation was found between mononuclear immune cells and density of c-kit+ and tryptase+ mast cells in OLP (r = 0.943 and r = 0.886, respectively). Our data demonstrate that the etiopathogenesis process of OLP and OLLC modulates the expansion and degranulation of mast cells; mast cells density, however, was similar between OLP and OLLC. The distribution of mast cells appears to vary along the lamina propria.

Exploring the Role of Lycium barbarum Polysaccharide in Corneal Injury Repair and Investigating the Relevant Mechanisms through In Vivo and In Vitro Experiments.

Lycium barbarum polysaccharide (LBP) is the main active component of Fructus Lycii, exhibiting various biological activities. This study aims to explore the protective effects of LBP on human corneal epithelial cells (HCEC) and a rat corneal injury model. Potential target points for LBP improving corneal injury repair were screened from public databases, and functional and pathway enrichment analyses of core targets were conducted using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Rat corneal alkali burns and HCEC oxidative stress injury models were established, and the results were validated through slit lamp examination, HE staining, TUNEL assay, immunofluorescence, CCK-8 assay, flow cytometry, scratch assay, and qRT-PCR methods. In the context of database retrieval, identification of 10 LBP monosaccharide components and 50 corneal injury repair-related targets was achieved. KEGG pathway analysis suggested that LBP might regulate the IL-17 and TNF signaling pathways through targets such as JUN, CASP3, and MMP9, thereby improving corneal damage. In vivo and in vitro experimental results indicated that LBP could reduce the increase of inflammation index scores (p < 0.05), inflammatory cell density (p < 0.01), TUNEL-positive cells (p < 0.01), corneal opacity scores (p < 0.01), and expression of corneal stromal fibrosis-related proteins α-SMA, FN, and COL (p < 0.01) caused by chemical damage to rat corneas. LBP inhibited oxidative stress-induced decreases in cell viability (p < 0.001) and migration healing ability (p < 0.01) in HCECs, reducing apoptosis rates (p < 0.001), ROS levels (p < 0.001), and the expression of inflammatory factors TNF-α and IL-6 (p < 0.01). qRT-PCR results demonstrated that LBP intervention decreased the mRNA levels of JUN, CASP3, and MMP9 in H2O2-induced alkaline-burned corneas and HCECs (p < 0.01).The integrated results from network pharmacology and validation experiments suggest that the inhibitory effects of LBP on apoptosis, inflammation, and fibrosis after corneal injury may be achieved through the suppression of the TNF and IL-17 signaling pathways mediated by JUN, CASP3, and MMP9.

Translocator protein is a marker of activated microglia in rodent models but not human neurodegenerative diseases

Microglial activation plays central roles in neuroinflammatory and neurodegenerative diseases. Positron emission tomography (PET) targeting 18 kDa Translocator Protein (TSPO) is widely used for localising inflammation in vivo, but its quantitative interpretation remains uncertain. We show that TSPO expression increases in activated microglia in mouse brain disease models but does not change in a non-human primate disease model or in common neurodegenerative and neuroinflammatory human diseases. We describe genetic divergence in the TSPO gene promoter, consistent with the hypothesis that the increase in TSPO expression in activated myeloid cells depends on the transcription factor AP1 and is unique to a subset of rodent species within the Muroidea superfamily. Finally, we identify LCP2 and TFEC as potential markers of microglial activation in humans. These data emphasise that TSPO expression in human myeloid cells is related to different phenomena than in mice, and that TSPO-PET signals in humans reflect the density of inflammatory cells rather than activation state.

Toxoplasma gondii attenuates the ethidium bromide induced demyelination lesions in multiple sclerosis model rats

Multiple sclerosis (MS) is an autoimmune neurodegenerative disease. Since the modulation of the immune system by parasites has been proven, and there have been reports of a reduction in the clinical symptoms of MS in people with toxoplasmosis, this study aimed to investigate the effect of toxoplasmosis on MS in an animal model. MS model was induced by the ethidium bromide injection in the areas specified in the Rat's brain in the stereotaxic device and Toxoplasma gondii RH strain injection of the rat's peritoneal for creation of toxoplasmosis. The effect of acute and chronic toxoplasmosis on the MS model was evaluated by examining the development of clinical symptoms of MS, body weight, changes in the levels of inflammatory cytokines, inflammatory cell infiltration, cell density, and spongy tissue in the brain. The body weight in the acute toxoplasmosis with MS was the same as the MS group, and a significant decrease was observed, but no weight loss was observed in the chronic toxoplasmosis with MS. In the chronic toxoplasmosis, the progress of clinical signs such as Immobility of limbs, including tail, hands, and feet, was observed less compared to other groups. The histology results in the group of chronic toxoplasmosis showed high cell density and inhibition of spongy tissue formation, and the infiltration of inflammatory cells in this group was less. TNF-α and INF-γ decreased in MS with chronic toxoplasmosis compared to the MS group. Our findings showed that chronic toxoplasmosis with inhibition of spongy tissue formation and prevention of cell infiltration and. As a result, the reduction of inflammatory cytokines could reduce clinical symptoms in MS in the animal model.

Mitigation of influenza-mediated inflammation by immunomodulatory matrix-bound nanovesicles.

Cytokine storm describes a life-threatening, systemic inflammatory syndrome characterized by elevated levels of proinflammatory cytokines and immune cell hyperactivation associated with multi-organ dysfunction. Matrix-bound nanovesicles (MBV) are a subclass of extracellular vesicle shown to down-regulate proinflammatory immune responses. The objective of this study was to assess the efficacy of MBV in mediating influenza-induced acute respiratory distress syndrome and cytokine storm in a murine model. Intravenous administration of MBV decreased influenza-mediated total lung inflammatory cell density, proinflammatory macrophage frequencies, and proinflammatory cytokines at 7 and 21 days following viral inoculation. MBV decreased long-lasting alveolitis and the proportion of lung undergoing inflammatory tissue repair at day 21. MBV increased the proportion of activated anti-viral CD4+ and CD8+ T cells at day 7 and memory-like CD62L+ CD44+, CD4+, and CD8+ T cells at day 21. These results show immunomodulatory properties of MBV that may benefit the treatment of viral-mediated pulmonary inflammation with applicability to other viral diseases such as SARS-CoV-2.

Textural properties of microglial activation in Alzheimer's disease as measured by (R)-[11C]PK11195 PET.

Alzheimer's disease is the most common form of dementia worldwide, accounting for 60-70% of diagnosed cases. According to the current understanding of molecular pathogenesis, the main hallmarks of this disease are the abnormal accumulation of amyloid plaques and neurofibrillary tangles. Therefore, biomarkers reflecting these underlying biological mechanisms are recognized as valid tools for an early diagnosis of Alzheimer's disease. Inflammatory mechanisms, such as microglial activation, are known to be involved in Alzheimer's disease onset and progression. This activated state of the microglia is associated with increased expression of the translocator protein 18 kDa. On that account, PET tracers capable of measuring this signature, such as (R)-[11C]PK11195, might be instrumental in assessing the state and evolution of Alzheimer's disease. This study aims to investigate the potential of Gray Level Co-occurrence Matrix-based textural parameters as an alternative to conventional quantification using kinetic models in (R)-[11C]PK11195 PET images. To achieve this goal, kinetic and textural parameters were computed on (R)-[11C]PK11195 PET images of 19 patients with an early diagnosis of Alzheimer's disease and 21 healthy controls and submitted separately to classification using a linear support vector machine. The classifier built using the textural parameters showed no inferior performance compared to the classical kinetic approach, yielding a slightly larger classification accuracy (accuracy of 0.7000, sensitivity of 0.6957, specificity of 0.7059 and balanced accuracy of 0.6967). In conclusion, our results support the notion that textural parameters may be an alternative to conventional quantification using kinetic models in (R)-[11C]PK11195 PET images. The proposed quantification method makes it possible to use simpler scanning procedures, which increase patient comfort and convenience. We further speculate that textural parameters may also provide an alternative to kinetic analysis in (R)-[11C]PK11195 PET neuroimaging studies involving other neurodegenerative disorders. Finally, we recognize that the potential role of this tracer is not in diagnosis but rather in the assessment and progression of the diffuse and dynamic distribution of inflammatory cell density in this disorder as a promising therapeutic target.

Abstract 4631: Multiplex IHC assay to explore regional heterogeneity of FAP and inflammatory cell density in localized prostatic adenocarcinoma

Abstract Cancer-associated fibroblasts (CAFs) expressing FAP promote tumor growth, invasion and immune suppression. FAP is a molecular imaging target in cancer and its protease activity is a potential anti-cancer drug target. While FAP expression was associated with biochemical recurrence after prostatectomy using tissue microarrays (TMAs)(DOI:10.1158/2767-9764.CRC-21-0183), its expression has not been comprehensively correlated with morphological features of disease aggressiveness beyond grade. 48 cases of localized prostatic adenocarcinoma were used for a multiplex immunohistochemical assay that included FAP, CD45, CD163, p63 and Keratin 8. Each of these markers were individually optimized by single-plex staining and were then performed as an iterative IHC assay (PMID:35188986) and quantification was performed using the HALO image analysis platform (Indica Labs). We developed a second multiplex assay including FAP, vimentin, smooth muscle actin, desmin, CD31, S100, keratin 8 and p63. FAP IHC staining was analytically validated using a series of positive and negative cell lines. In normal appearing (non-inflamed) prostate regions, FAP expression was negative. By contrast, upregulation of FAP was observed in the stromal compartment in regions of chronic inflammation and some proliferative inflammatory atrophy (PIA) lesions. In tumor regions, only 1 case was totally negative for FAP. Except for 2 cases, in which there was focal weak tumor cell staining, all FAP expression was present in the tumor stromal compartment (TSC). The vast majority of FAP expression was associated with Vim+/Des- fibroblasts, which at times were also positive for SMA (Vim+/Des-/SMA+), indicating they are myofibroblasts. There was very infrequent FAP expression associated with M2 macrophages, endothelial cells, nerves and vimentin-negative smooth muscle cells, indicating that the majority of FAP expression occurs in fibroblasts. Preliminary quantitative data using visual estimations of the fraction of TSC expressing FAP (range, 0-80%, mean=35.8%, median=30%, SD=23.7) was not associated with the overall GS/grade group, but was associated with non-organ confined disease. Furthermore, there was a trend towards increased FAP expression in cases showing intraductal carcinoma and large cribriform formation. Ongoing studies are in process to obtain quantitative data by image analysis and to correlate FAP expression with the presence of overall inflammatory cell density and the density of M2 macrophages. Additionally, we will characterize the cases in terms of molecular features including TMPRSS2-ERG status and PTEN genomic status. Future use of these panels will facilitate studies of associations of FAP with clinical outcome, MRI and PET imaging, response to specific treatments and to help characterize FAP as a predictor of response to emerging FAP inhibitors and FAP-targeted prodrugs. Citation Format: Fernanda Caramella Pereira, Alan K. Meeker, Kenneth Pienta, Qizhi Zheng, Tracy Jones, Srinivasan Yegnasubramanian, Jessica L. Hicks, Sujayita Roy, Angelo M. De Marzo, W. Nathaniel Brennen. Multiplex IHC assay to explore regional heterogeneity of FAP and inflammatory cell density in localized prostatic adenocarcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4631.

Correlations Between Inflammatory Cell Infiltration and Relative Density and the Boundary Manifestation of Pulmonary Non-Neoplastic Ground Glass Nodules.

To investigate the influence factors for the various boundary manifestations of pulmonary non-neoplastic ground glass nodules (GGNs) on computed tomography (CT). From January 2015 to March 2022, a total of 280 patients with 318 non-neoplastic GGNs were enrolled. The correlations between degree of inflammatory cell infiltration and relative density (ΔCT) and the boundary manifestations of lesions were evaluated, respectively. Nongranulomatous nodules (283, 89.0%) with fibrous tissue proliferation and/or inflammatory cells as the predominant pathological findings were the most common non-neoplastic GGNs, followed by granulomatous nodules (28, 8.8%). Among nongranulomatous GGNs, cases with more and less/no inflammatory cells were 15 (10.9%) and 122 (89.1%) in 137 well-defined ones with smooth margin, 16 (24.6%) and 49 (75.4%) in 65 well-defined ones with coarse margin, 43 (91.5%) and 4 (8.5%) in 47 ill-defined ones with higher ΔCT (>151HU), and 4 (11.8%) and 30 (88.2%) in 34 ill-defined ones with lower ΔCT (< 151HU). The proportion of cases with more inflammatory cells in well-defined nodules was similar to that in ill-defined ones with lower ΔCT (P = 0.587) but significantly lower than that in ill-defined ones with higher ΔCT (P < 0.001). Among the granulomatous nodules, ill-defined cases with higher ΔCT (16, 57.1%) were the most common, and they (7/8, 87.5%) frequently had changes during short-term follow-up. Nongranulomatous nodules are the most common non-neoplastic GGNs, their diverse boundary manifestations closely correlate with degree of inflammatory cell infiltration and density difference.

The effects of smoking on genotoxic and histopathologic damage in exfoliated oral epithelial cells and the periodontium: A cross-sectional study.

Smoking negatively affects the prognosis of periodontal disease by impairing tissue healing. While micronucleus is the most popular parameter for demonstrating DNA damage, inflammatory cell and vascular densities are the most evaluated parameters for determining histopathologic changes in the periodontium. This study aimed to study the effects of periodontitis and cigarette smoking on genotoxic changes in exfoliated oral epithelial cells and histopathologic changes in periodontal tissue. A cross-sectional study was conducted between November 2018 and July 2019 at a dental university hospital in Turkey, and registered as NCT05484765. Eighty systemically healthy subjects were divided into four groups according to periodontal status and smoking habits: 20 smokers with generalized periodontitis (SGP), 20 nonsmokers with generalized periodontitis (NGP), 20 smokers with healthy periodontium (SHP), and 20 nonsmokers with healthy periodontium (NHP). For each study participant, full-mouth clinical periodontal parameters (CPPs) were measured, smear samples were taken from buccal and gingival mucosa, and periodontal tissue was biopsied from the maxillary molars. Cytogenetic and histopathologic assays (primary and secondary outcomes) were conducted using Feulgen reaction and hematoxylin-eosin staining, respectively. The mean CPPs of healthy periodontium groups were lower than generalized periodontitis groups. No significant differences were found between other groups regarding CPPs. Buccal micronuclei counts in groups decreased with the highest to lowest counts occurring in the order SGP > SHP > NGP > NHP. Gingival micronuclei counts in groups decreased from SGP > SHP > NGP = NHP. The most intense inflammatory cell and vascular densities occurred in SGP and NGP groups, respectively; and the mildest values were in healthy periodontium groups. Histopathological damage score decreased significantly by group in order SGP > NGP > SHP > NHP. The synergy arising from the combination of smoking and periodontitis exposures exacerbates genotoxic and histopathologic damage in oral cells and the periodontium.

Immunohistochemical analysis with apoptosis and autophagy markers in periodontitis and peri-implantitis: Clinical comparative study.

Recently, the terms autophagy and apoptosis have been studied on implants, especially in cell culture and in vitro studies, but in vivo evaluations are limited. The aim of this study was to compare the differences in apoptosis and autophagy intensity at the molecular and cellular level in periodontal and peri-implant diseases. Sixty-four biopsy samples were obtained from 52 patients, 36 female and 16 male, whose mean age was between 18 and 75, and were included in the study. The periodontitis group was defined as PG (n:30 sample) and the peri-implantitis group as IG (n:34 samples). Granulation tissues as biopsy materials were collected, and immunohistochemical analysis was performed with hematoxylin-eosin, Masson's trichrome, anti-MAP1LC3A, anti-beclin, and anti-active caspase-3 antibodies and terminal TdT-mediated dUTP-biotin nick end labeling (TUNEL) methods. The histological slide images were evaluated with the ImageJ software program. Inflammatory cell density in epithelial tissue, inflammatory cell density in connective tissue, the density of necrotic tissue debris, and collagen density in connective tissue were scored between 0 and 3 (0: none, 1: minimal, 2: moderate, 3: severe by hematoxylin-eosin and Masson's trichrome). The antibody binding reaction areas were evaluated per unit area (mm2 ) in connective tissue by immunohistochemical examination. As histochemical evaluations, there was no statistically significant differences the mean inflammatory cell density value in the epithelial tissue, inflammatory cell density value in the connective tissue, density value of necrotic tissue debris, collagen density value in the connective tissue between the groups. There was no statistically significant difference on immunohistochemical staining with LC3, caspase-3, Beclin-1 and TUNEL between the two groups (p > .05). A higher rate of inflammatory accumulation was shown on peri-implantitis, but no difference was found between periodontitis and peri-implantitis according to autophagy and apoptosis markers. Studies with high sample sizes with different markers are needed.

Osteopontin expression and the effect of anti-VLA-4 mAb treatment in experimental autoimmune encephalomyelitis, amouse model of multiple sclerosis.

Osteopontin (OPN) is involved in the pathogenesis of multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). The aim of this study was to investigate the expression of OPN in spinal cords of mice in the successive phases of EAE, to compare it with the density of inflammatory cells, oligodendrocytes and with the expression of interleukin (IL)-17A and to assess the effect of anti-α4β1 integrin (VLA-4) treatment. Experimental autoimmune encephalomyelitis (EAE) mice were injected with anti-VLA-4 antibodies or, as treatment control, with immunoglobulin G (IgG). Spinal cords were sectioned and immunostained for OPN, CD45 (overall leukocytes), CD3 (T cells), Iba1 (activated macrophages/microglia), IL-17A, and CNP1 (oligodendrocytes). Microscopic images were analysed and the percentage of immunopositive areas encompassing the whole spinal cord cross-sectional area were assessed in images for each antigen. Osteopontin was expressed by inflammatory cells and by a minority of neurons and blood vessels. Most of the studied parameters followed the temporal pattern of clinical scores: increase in the peak phase and decrease in the chronic phase. Only OPN and IL-17A remained at a high level in the chronic phase, while CNP1 expression gradually decreased in the successive phases. Anti-VLA-4 treatment lowered the expression of the studied antigens in the peak and chronic phases with the exception of oligodendrocyte marker CNP1 which in both phases showed an increased expression. Involvement of OPN is particularly significant in advanced EAE. Anti-VLA-4 treatment not only inhibits migration of myelin-reactive T cells, but also downregulates OPN and inhibits loss of oligodendrocytes.

The Effect of Melatonin on Nasal Septal Wound Healing in an Experimental Animal Model.

The purpose of our study was to examine the effect of melatonin (MLT) on wound healing in the nasal septum. Twenty-two Sprague-Dawley rats of the male sex were included in this experimental study. Nasal septal perforation (NSP), about 2 mm in diameter, was formed in each rat. MLT was applied topically to the subjects in the study group and saline was applied topically to the subjects in the control group once a day for 14 days. On day 14, the rats were sacrificed and the nasal septums of the subjects were resected for pathological evaluation. In the NSP area, degeneration and regeneration of nasal septal epithelium; degeneration and regeneration of the septal cartilage; number of cells involved in wound healing such as acute inflammatory cells (leukocytes), fibroblast, eosinophil, and giant cell; capillary vessel intensity; granulation tissue formation; and collagen intensity parameters were evaluated histopathologically. The macroscopic size and histopathologic examination results of NSPs were statistically analyzed. In the MLT group, the epithelium regeneration, cartilage regeneration, fibroblast number, collagen density, vascularity, and granulation formation were significantly higher, and the epithelial degeneration and acute inflammatory cells density were significantly lower, in the NSP area (p < 0.05). In addition, macroscopic healing was significantly higher in the MLT group (p = 0.044 and <0.05). Local application of MLT accelerates nasal septal wound healing. With this feature, the usage of MLT can be promising to prevent the formation of NSP.

Histological and biochemical evaluation of plasma rich in growth factors treatment for grade II muscle injuries in sheep

The purpose of this study was to perform a histological and biochemical evaluation of the influence of plasma rich in growth factors (PRGF) on muscle regeneration process after a surgically induced grade II muscle laceration. A randomized, single blind, controlled experimental research was conducted including twenty-one adult healthy sheep, randomly divided in three groups (n = 7). A grade II surgical section was performed in the biceps femoris muscle of both hindlimbs. After two days (basal time), intralesional infiltration of autologous PRGF or Saline solution was randomly administered in both hindlimbs. Treatment was repeated once a week. Animal groups were euthanized at 1 (T1), 2 (T2) or 4 (T4) weeks. Histological assessment showed that PRGF intralesional injection induced a significant decrease of inflammatory cells density, significant higher centrally nucleated fibers percentage and significantly smaller fibrotic areas compared to Saline-treated muscles at T1, T2 and T4. Also, lower vascular density, with lower capillaries cross-sectional area, in PRGF group compared to Saline was observed. Biochemical analysis revealed a significant higher expression level of MYOD1, MYF5 and MYOG genes in PRGF groups at T1 compared to Saline treated muscles. At ultrastructural level, PRGF groups presented scarce edema and loss of connective tissue structure, as well as higher mitochondrial density adequately associated to the sarcomere unit in contrast to the Saline group. In conclusion, histological, biochemical, and ultrastructural results showed that PRGF treatment improved muscle regeneration process leading to more mature histological aspect in newly formed muscle tissue after a surgically induced grade II muscle injury.

The effect of hypertonic alkaline nasal irrigation on nasal wound healing in an experimental animal model

Objectives: This study aimed to examine the effect of a hypertonic alkaline nasal irrigation (HANI) solution on nasal healing in an animal model of nasal septal perforation (NSP). Materials and Methods: In the experimental animal study, 22 healthy male Sprague-Dawley rats were divided in to two groups: the HANI (study) group and the saline (control) group. An NSP about 2 mm in size was formed in each rat. In the study group, 0.1 mL of HANI was intranasally administered each day for 14 days, whereas the control group daily received 0.1 mL of saline for the same period. The animals were sacrificed on Day 14, and the subjects’ nasal septums were excised for histopathology. The amount of regeneration and degeneration of epithelial tissue, inflammatory cell count, fibroblast count, amount of collagen, new vessel formation, amount of granulation, giant cell count, eosinophil count, and the degeneration and regeneration of cartilage tissue were examined. The macroscopic recovery rates of NPSs and microscopic parameters were statistically analyzed. Results: The acute inflammatory cell density was significantly lower in the study group (p=0.033). The epithelial and cartilage regenerations, fibroblast number, vascularization, amount of granulation, and collagen density were higher in the study group. In addition, the epithelial and cartilage degenerations were lower in the study group. However, no significant difference was detected in the evaluation of the remaining parameters (p&gt;0.05). Conclusion: Hypertonic alkaline nasal irrigation may not adversely affect nasal wound healing and may reduce acute inflammation in nasal septal wound healing in an NSP animal model.

The effect of adding carboxymethylcellulose and alginate to hyaluronic acid on reducing epidural fibrosis in a lumbar laminectomized rat model

This study aimed to compare the anti-epidural fibrosis and anti-inflammation effects of hyaluronic acid (HA)-carboxymethylcellulose (CMC)-alginate hydrogel, pure HA, and normal saline using a lumbar laminectomized rat model. Thirty lumbar laminectomized adult rats were randomly assigned to three groups. The control group received normal saline, the HCA group received HA-CMC-alginate gel, and the HA group received pure HA gel soaked over the dura of the laminectomized area before closing the surgical wound. All rats were housed for eight weeks, then epidural fibrosis (EF) was histologically graded. In addition, the fibroblast and inflammatory cell density were computerized for evaluation. The mean fibroblast densities were 32.03 × 102 ± 488, 13.22 × 102 ± 200, and 14.52 × 102 ± 368 cell/mm2 in the control, HCA, and HA groups, respectively. The mean inflammatory cell density was 30.74 × 102 ± 459, 5.90 × 102 ± 129, and 11.08 × 102 ± 282 cell/mm2 in the control, HCA, and HA groups, respectively. The mean fibroblast and inflammatory cell densities in the HCA and HA groups were significantly lower than in the control group (P < 0.05). The HCA group had a significantly lower inflammatory cell density than the HA group (P < 0.05). The fibrous adherence grading of HCA and HA was significantly lower than the control (P < 0.05). HA-CMC-alginate gel and HA hydrogels seem to have a better preventative effect on EF than no treatment (control). HA-CMCalginate can exhibit a better anti-inflammatory effect than HA. HA-CMC-alginate can be effective in reducing EF and inflammation after lumbar laminectomy.

Transcranial direct current stimulation as a preventive treatment in multiple sclerosis? Preclinical evidence

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system, presenting with optic neuritis in about 20–30% of cases. Optic nerve demyelination, associated with delay of visual evoked potentials (VEPs), is also observed prior to motor signs in the preclinical MS model Experimental Autoimmune Encephalomyelitis (EAE). Transcranial direct current stimulation (tDCS), inducing polarity-dependent changes in neuronal excitability, is widely used to promote neuroplasticity in several neurological disorders. However, its potential effects on inflammation and demyelination are largely unknown. We tested the effectiveness of a preventive, 5-day tDCS treatment started 3 days post-immunization, in reducing the severity of VEP delays observed in early EAE. In mice undergoing cathodal tDCS (n = 6/26 eyes) VEPs were significantly less delayed compared with eyes from EAE-Sham (n = 24/32 eyes) and EAE-Anodal (n = 22/32 eyes). Optic nerve immunohistochemistry revealed a significantly lower cell density of microglia/macrophages, and less axonal loss in EAE-Cathodal vs EAE-Sham and EAE-Anodal, while the percent demyelination with Luxol-fast blue staining was comparable among EAE groups. Considering the latter result, immunofluorescence paranodal staining was performed, revealing a significantly higher number of complete paranode domains in EAE-Cathodal, closer to healthy mice, compared with EAE-Sham and EAE-Anodal groups. These results were reflected by the negative correlation between the number of complete paranode domains and VEP latency increase with respect to pre-immunization. Finally, cathodal tDCS was associated with a lower number, closer to healthy, of single paranodes in contrast to EAE-Sham. The effects of cathodal stimulation in preventing VEPs delays and optic nerve myelin damage were already observed in the pre-motor onset EAE stage, and were associated with a lower density of inflammatory cells. These findings suggest that tDCS may exert an anti-inflammatory effect with potential therapeutic application to be further explored in autoimmune demyelinating diseases.

The effects of Feijoa sellowiana fruit extract on wound healing in rats: a stereological and molecular study.

The aim of this study was to evaluate the anti-inflammatory and wound-healing potential of Feijoa sellowiana fruit extract using stereological and molecular methods in experimental rat models. Male Wistar rats were divided into four equal groups: non-treated, vehicle, Feijoa sellowiana fruit extract ointment (5% weight/weight) and the reference drug (madecassol). All animals were treated topically once per day. At the end of the study, wound samples were harvested for histological, stereological, immunohistochemical and molecular assessments to determine the in vivo healing potential and anti-inflammatory activity. A high-performance liquid chromatography (HPLC) analysis was performed for the characterisation of the phenolic acids in the extract. The study included 64 rats in total. Our results showed that the wound closure, volume of new epidermis and dermis, density of fibroblasts and blood vessels, and the deposition of collagen were significantly higher in both extract and madecassol groups compared to the non-treated and vehicle groups, with superior healing in the extract group. The transcript for the transforming growth factor (TGF)-β gene was significantly upregulated in both extract and madecassol groups compared to non-treated and vehicle groups and was highest for the extract group. The density of inflammatory cells and expression levels of the cyclooxygenase (COX)-2 protein and tumour necrosis factor (TNF)-α gene in the extract and madecassol groups, especially in the extract group, were significantly reduced compared to non-treated and vehicle groups. Our results confirm that the Feijoa sellowiana fruit extract is a valuable source of antioxidant and anti-inflammatory activities and can allow for damaged tissue in wounds to recover markedly.

Targeting inflammatory monocytes by immune-modifying nanoparticles prevents acute kidney allograft rejection

Inflammatory monocytes are a major component of the cellular infiltrate in acutely rejecting human kidney allografts. Since immune-modifying nanoparticles (IMPs) bind to circulating inflammatory monocytes via the specific scavenger receptor MARCO, causing diversion to the spleen and subsequent apoptosis, we investigated the therapeutic potential of negatively charged, 500-nm diameter polystyrene IMPs to prevent kidney allograft rejection. Kidney transplants were performed from BALB/c (H2d) to C57BL/6 (H2b) mice in two groups: controls (allo) and allo mice infused with IMPs. Groups were studied for 14 (acute rejection) or 100 (chronic rejection) days. Allo mice receiving IMPs exhibited superior survival and markedly less acute rejection, with better kidney function, less tubulitis, and diminished inflammatory cell density, cytokine and cytotoxic molecule expression in the allograft and lower titers of donor-specific IgG2c antibody in serum at day 14, as compared to allo mice. Cells isolated from kidneys from allo mice receiving IMPs showed reduced Ly6Chi monocytes, CD11b+ cells and NKT+ cells compared to allo mice. IMPs predominantly bound CD11b+ cells in the bloodstream and CD11b+ and CD11c-B220+ marginal zone B cells in the spleen. In the spleen, IMPs were found predominantly in red pulp, colocalized with MARCO and expression of cleaved caspase-3. At day 100, allo mice receiving IMPs exhibited reduced macrophage M1 responses but were not protected from chronic rejection. IMPs afforded significant protection from acute rejection, inhibiting both innate and adaptive alloimmunity. Thus, our current experimental findings, coupled with our earlier demonstration of IMP-induced protection in kidney ischemia-reperfusion injury, identify IMPs as a potential induction agent in kidney transplantation.