A minimally invasive approach to spleen histopathology in dogs: A new method for follow-up studies of spleen changes in the course of Leishmania infantum infection

Aflatoxin B1 exposure causes splenic pyroptosis by disturbing the gut microbiota-immune axis

Aflatoxin B1 (AFB1) causes serious immunotoxicity and has attracted considerable attention owing to its high sensitivity and common chemical-viral interactions in living organisms. However, the sensitivity of different species to AFB1 widely varies, which cannot be explained by the different metabolism in species. The gut microbiota plays a crucial role in the immune system, but the interaction of the microbiota with AFB1-induced immunotoxicity still needs to be determined. Our results indicated that AFB1 exposure disrupted the structure of the gut microbiota and damaged the gut barrier, which caused translocation of microbiota metabolites, lipopolysaccharides, to the spleen. Subsequently, pyroptosis of the spleen was activated. Interestingly, AFB1 exposure had little effect on the splenic pyroptosis of pseudo-germfree mice (antibiotic mixtures eliminated their gut microbiota, ABX). Then, fecal microbiota transplant (FMT) and sterile fecal filtrate (SFF) were employed to validate the function of the gut microbiota and its metabolites in AFB1-induced splenic pyroptosis. The AFB1-disrupted microbiota and its metabolites significantly promoted splenic pyroptosis, which was worse than that in control mice. Overall, AFB1-induced splenic pyroptosis is associated with the gut microbiota and its metabolites, which was further demonstrated by FMT and SFF. The mechanism of AFB1-induced splenic pyroptosis was explored for the first time, which paves a new way for preventing and treating the immunotoxicity from mycotoxins by regulating the gut microbiota.

Histopathological Parameters of Canine Bone Marrow in Cell-Block Preparations

Studies using the cell-block technique for bone marrow (BM) analysis are limited in the veterinary literature. This work assessed whether the histopathological analysis of canine BM was feasible using cell-block cytoinclusions prepared from fine-needle sternal aspirate samples. Eight clinically healthy young-to-middle-aged dogs underwent both fine-needle sternal aspiration for BM cell-block (BM-Cb) processing and iliac-crest BM core biopsy (BM-B). Histopathologic parameters were compared between the 2 methods. There were no statistically significant histopathological differences between hematopoietic tissue areas (P =  .6294) in the BM-Cb and BM-B sections, and they had similar microscopic characteristics and microarchitecture. Cellularity and reticulin-fiber staining were equivalent in the BM-Cb and BM-B preparations in 87.5% (7/8) and 100% (8/8) of the sections, respectively. However, the quantitative results of the megakaryocytic series differed between BM-Cb and BM-B in 37.5% (3/8) of the sections, and the myeloid:erythroid (M:E) ratios differed between the 2 methods in 25% (2/8). These preliminary data indicate that cell-block preparations made from sternal fine-needle aspiration samples warrant continued evaluation in a larger number of animals, including those with various diseases affecting the bone marrow.

Cytokines and splenic remodelling during Leishmania donovani infection

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Visceral leishmaniasis leads to extensive remodelling of splenic microarchitecture.

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Splenomegaly is associated with compartmentalised vascular remodelling.

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Alterations in white pulp stromal cells affects leucocyte segregation.

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Splenic remodelling involves multiple cytokines from diverse cellular sources.

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Understanding splenic remodelling may lead to new therapeutic interventions.

Visceral leishmaniasis (VL) causes extensive splenic pathology that contributes to dysfunctional immune responses, in part through displacement and destruction of cell populations involved in maintaining splenic structural integrity. The expression of pro and anti-inflammatory cytokines and chemokines is crucial in orchestrating the delicate balance that exists between host resistance and tissue pathology. In an effort to restore homeostatic balance to the local microenvironment, remodelling of the splenic architecture occurs in a compartmentalised manner to retain some level of functionality, despite persistent inflammatory pressures. Animal models of VL as well as human studies have significantly contributed to our understanding of the architectural changes that occur in the spleen during VL. Here, we review the role of cytokines in mediating microarchitectural changes associated with the development of splenomegaly during VL.

Evaluation of Cytopathological Techniques for the Diagnosis of Canine Visceral Leishmaniosis with Lymph Node Samples

The identification of the parasite in cytological smears of lymph node aspirates is a widely applied technique for the direct diagnosis of Leishmania spp. infection, especially in endemic areas. Although very specific, this method has limited sensitivity, and improving the technique would be highly desirable. This study aimed to evaluate the efficacy of conventional smear cytology (SC), liquid-based cytology (LBC), cell block (CB) stained with haematoxylin and eosin (HE) and immunocytochemistry (ICC), and formalin-fixed paraffin wax-embedded tissue immunohistochemistry (FFPE-IHC) compared with serology and polymerase chain reaction for the diagnosis of canine visceral leishmaniosis (CVL) in lymphoid tissue. The use of a preservative medium and centrifugation for cytological samples reduced the number of unsatisfactory artefacts/background. Moreover, LBC allowed excellent cellular preservation and the application of ancillary techniques, such as CB and ICC. SC was the most accurate morphological diagnostic method (45.0%). CB-ICC alone or associated with SC demonstrated significantly higher sensitivity (70.0% and 72.0%, respectively) when compared with SC alone (34.00%). CB-ICC was found to be more effective in the detection of infected animals with mild clinical signs, similar to FFPE-IHC. The specificity and positive predictive value were similar between all methods. Finally, the detection limit for CB-ICC and SC + CB-ICC was identical (18.46 amastigotes/mm²). Our study suggests that CB-ICC is a promising tool for improvement of the cytopathological diagnosis of CVL and may be applied in routine epidemiological screening.

Histological Disorganization of Spleen Compartments and Severe Visceral Leishmaniasis

The spleen is a secondary lymphoid organ responsible for immune surveillance against blood-circulating pathogens. Absence of the spleen is associated with increased susceptibility to systemic spread and fatal infection by different pathogens. Severe forms of visceral leishmaniasis are associated with disorganization of spleen compartments where cell interactions essential for splenic immunological function take place. White pulp atrophies, secondary lymphoid follicles and marginal zones vanish, and the boundaries separating white and red pulp blur. Leukocyte populations are reduced or disappear or are replaced by plasma cells. In this paper, we review the published data on spleen disorganization in severe forms of visceral leishmaniasis and propose a histological classification to help the exchange of information among research groups.

Clinical significance and effect of AEG-1 on the proliferation, invasion, and migration of NSCLC: a study based on immunohistochemistry, TCGA, bioinformatics, in vitro and in vivo verification

Background

Astrocyte elevated gene-1 (AEG-1) is related to the tumorigenesis and deterioration of different cancers, including non-small cell lung cancer (NSCLC). However, the effect of AEG-1 in NSCLC remains unclear. In this study, we aimed to investigate the clinical significance and effect of AEG-1 on biological function of NSCLC.

Results

AEG-1 was significantly overexpressed in NSCLC tissues and closely correlated to the deterioration of NSCLC based on tissue microarray, TCGA database and meta-analysis. After knock-down of AEG-1, the proliferation, migration and invasion of NSCLC cells were all inhibited, and the tumorigenic and angiogenic ability of NSCLC cells were weakened. Furthermore, the AEG-1 co-expressed genes were significantly related to AMPK signaling pathway based on bioinformatics approaches.

Materials and Methods

A tissue microarray, the Cancer Genome Atlas (TCGA) database, as well as a meta-analysis were performed to analyze the relationship between AEG-1 and the clinicopathological parameters of NSCLC. Furthermore, immunocytochemistry, Western blot analysis, scratch assay, colony formation assay, Transwell migration and invasion assay and the chick embryo chorioallantoic membrane (CAM) model were conducted to explore the effect of AEG-1 on NSCLC in vitro and in vivo. Additionally, bioinformatics analyses were carried out to assess the potential pathways and networks of the co-expressed genes of AEG-1.

Conclusions

AEG-1 is positively activated in the tumorigenesis and deterioration of NSCLC. We hypothesize that AEG-1 could play an important role in NSCLC via AMPK signaling pathway. Inhibiting the expression of AEG-1 is expected to become a novel method in the therapeutic strategies of NSCLC.