Detection of melanin in the rat skin

Melanogenesis disorder is called dyschromia, is involved in various conditions including vitiligo, solar lentigo, and melanoma, the last of which is the most malignant type of skin cancer.

AIM

The aim of study was focused on histological visualization of melanogenic system.

MATERIALS AND METHODS

To investigate the roles of melanocytes and melanin, we used a rat skin as an experimental animal. Samples were stained using hematoxylin-eosin, the Schmorl's technique, the Fontana-Masson technique, the Warthin-Starry technique, and the S100 immunohistochemistry marker technique. Microscopy images were analyzed using the ImageJ free software protocol.

RESULTS

We found Fontana-Masson staining to be the most suitable for obtaining reliable results compared with the other methods, which had more disadvantages. We also found the S100 marker staining to be an effective tool for measuring the melanocyte count.

CONCLUSIONS

We consider the ImageJ processing protocol and staining procedures to be useful tools to estimate melanin and melanocyte pathology.

MicroRNA-542-3p Regulates P-glycoprotein Expression in Rat Epilepsy via the Toll-like Receptor 4/Nuclear Factor-kappaB Signaling Pathway

BACKGROUND

The function of microRNA-542-3p (miR-542-3p) in rat epilepsy is still unclear.

METHODS

The levels of miR-542-3p and toll-like receptor 4 (TLR4) were determined through quantitative real-time PCR. The protein levels were examined via the western blot analysis. The relationship between miR-542-3p and TLR4 was confirmed through luciferase assay. Pathological changes were analyzed via Hematoxylin-eosin (HE) and Nissl staining.

RESULTS

The rats and hippocampal cells were treated with kainic acid (KA) in vivo and in vitro. miR-542-3p was low in KA-treated rats, hippocampal cells and cerebrospinal fluid of patients with epilepsy. Further functional analysis showed that miR-542-3p overexpression inhibited KAinduced average seizure frequency, damage of hippocampal neuron and cell apoptosis, leading to the alleviation of the brain injury in epilepsy rats. miR-542-3p was determined to downregulate TLR4 expression. The relationship between miR-542-3p and TLR4 was confirmed. TLR4 knockdown reduced KA-induced nuclear factor-kappa B p65 (NF-κB p65), multidrug resistance 1 (MDR1), P-glycoprotein (P-gp) and apoptosis-associated protein levels. Further, for NF-κB p65, MDR1, P-gp and apoptosis-associated protein levels detection, miR-542-3p mimic showed a suppressive effect on these KA-induced protein levels, whereas TLR4 overexpression ameliorated the miR-542-3p-induced these protein levels in KA-treated epilepsy rats.

CONCLUSION

We identified that miR-542-3p attenuated seizure-induced brain injury and the expression of P-gp in epilepsy rats through inhibiting TLR4/NF-κB signaling pathway, which might contribute to improved epilepsy therapy.

Gant61 ameliorates CCl4-induced liver fibrosis by inhibition of Hedgehog signaling activity

As an intercellular signaling molecule, Hedgehog (Hh) plays a critical role in liver fibrosis/regeneration. Transcription effectors Gli1 and Gli2 are key components of the Hh signaling pathway. However, whether inhibition of Gli1/2 activity can affect liver fibrogenesis is largely unknown. In the present study, we investigated the effect of Gant61 (a Gli1/2 transcription factor inhibitor) on liver fibrosis and its possible mechanism. Wild-type and Shh-EGFP-Cre male mice were exposed to CCl₄, and then treated with or without Gant61 for four weeks. The level of liver injury/fibrosis and expression levels of mRNA and protein related to the Hh ligand/pathway were assessed. In our study, CCl₄ treatment induced liver injury/fibrosis and promoted activation of hepatic stellate cells (HSCs). In addition, CCl₄ induced the expression of Shh ligands in and around the fibrotic lesion, accompanied by induction of mRNA and protein expression of Hh components (Smo, Gli1 and Gli2). However, administration of Gant61 decreased liver fibrosis by reduction in HSC number, down-regulation of mRNA and protein expression of Hh components (Smo, Gli1 and Gli2), and cell-cycle arrest of HSCs. Our data highlight the importance of the Shh pathway for the development of liver fibrosis, and also suggest Glis as potential therapeutic targets for the treatment of liver fibrosis.

A novel method for tissue segmentation in high-resolution H&E-stained histopathological whole-slide images

Tissue segmentation in whole-slide images is an important task in digital pathology, required for efficient and accurate computer-aided diagnostics. Precise tissue segmentation is particularly significant for a correct diagnosis in cases, when tissue structure of a specimen is very porous, such as skin specimens. In this paper, we addressed the problem of fore- and background segmentation in histopatological images of skin specimens stained with hematoxylin and eosin (H&E), which has not been solved yet, by a novel method based on a combination of statistical analysis, color thresholding, and binary morphology. We validated our algorithm on large extracts from 60 high-resolution whole slide images, with differing staining quality and captured under varying imaging conditions, from three laboratories. The size of extracts varies from 2000×1500 to 20000×30000 pixels and the number of images used in our study matches the number of H&E images used by other research teams. We compared our method to the published ones (GrabCut and FESI) and showed that our approach outperforms its counterparts (Jaccard index of 0.929 vs. 0.776 and 0.695).

The Effects of Halofuginone on Wound Healing in the Rat Nasal Mucosa

Background

Halofuginone is an alkaloid febrifugine analogue and bioactive molecule that was isolated incidentally from the Dichroa febrifuga plant. The therapeutic efficacy of halofuginone in parasitic infections, scleroderma, inflammation, and fibrosis-related diseases, as well as in some types of cancer, has been previously reported. The effects of halofuginone on nasal mucosal damage are not yet known.

Objective

The aim of this study was to investigate the potential effect of topically applied halofuginone on wound healing in the mechanically injured nasal mucosa of rats.

Methods

A unilateral mucosal wound was created in the nasal cavity of 32 rats (aged 4 weeks) using the brushing technique. These rats were randomly divided into 4 groups. Although the control group did not receive an intervention, a dry pad, a saline-impregnated pad, or a pad impregnated with halofuginone were placed in the rats of the other 3 groups and left for 5 minutes. Rats were sacrificed on the 14th day, and a histological examination was performed. The nasal mucosa was assessed via hematoxylin-eosin and Masson’s trichrome staining.

Results

There were no statistically significant differences in epithelial thickness, inflammation, goblet cell formation, and epithelial disarray values between the halofuginone group and the control group ( P > .05). The subepithelial thickness was significantly decreased in the saline-treated group and the halofuginone-treated group ( P < .05), but a significantly lower level of subepithelial fibrosis was only observed in the halofuginone group compared to the other groups ( P < .05).

Conclusions

Topical halofuginone administration reduces the development of fibrosis and subepithelial edema after experimentally induced nasal mucosal injury, but it does not exert therapeutic or preventive effects on epithelial damage, inflammation, and goblet cell hyperplasia.

Slide-free imaging of hematoxylin-eosin stained whole-mount tissues using combined third-harmonic generation and three-photon fluorescence microscopy

Intraoperative margin assessment of surgical tissues during cancer surgery is clinically important, especially in the case of tissue conserving surgery like Mohs micrographic surgery in which minimization of the surgical area is considered crucial. Frozen pathology is the gold standard of assessing excised tissues for signs of remaining cancerous lesions. The current protocol, however, is time-consuming and labor-intensive. Instead of the complex frozen sectioning, staining, and traditional white light microscopy imaging protocol, optically sectioned histopathological imaging of hematoxylin-eosin stained whole-mount skin tissues with a subfemtoliter resolution is demonstrated by using nonlinear microscopy in this study. With our proposed method, the reagents of staining and the contrast of imaging are fully consistent with the current clinical standard of frozen pathology, thus facilitating rapid intraoperative assessment of surgical tissues for future applications. Image: Slide-free nonlinear microscopy imaging of H&E stained whole-mount skin tissue showing the morphology of sweat glands.

Therapeutic potential of anti-IL-1β IgY in guinea pigs with allergic asthma induced by ovalbumin

BACKGROUND

Interleukin-1 beta (IL-1β) plays pivotal roles in the progression of allergic airway inflammation. This study aims to determine whether the blockade of IL-1β can inhibit airway inflammation in guinea pigs with allergic asthma induced by the inhalation of aerosolized ovalbumin (OVA).

METHODS

Healthy guinea pigs treated with saline were used as normal controls (group C). The guinea pigs with allergic asthma induced by the inhalation of aerosolized OVA were randomly divided into three groups: (1) the M group containing negative control animals treated with saline; (2) the Z1 group containing animals treated by the inhalation of atomized 0.1% anti-IL-1β immunoglobulin yolk (IgY); and (3) the Z2 group containing positive control animals that were treated with budesonide. The inflammatory cells in the peripheral blood (PB) and bronchoalveolar lavage fluid (BALF) were evaluated using methylene blue and eosin staining. Cytokine concentrations were measured using an enzyme-linked immunosorbent assay. Pulmonary sections were examined using hematoxylin-eosin staining.

RESULTS

Allergic inflammation and damage to the pulmonary tissues were decreased in the Z1 group compared to the M group. Eosinophils and neutrophils in the PB and BALF were significantly decreased in the Z1 group compared to the M group (P<0.05). Treatment with anti-IL-1β IgY significantly reduced the levels of IL-1β, IL-4, IL-8, IL-13, TNF-α, TGF-β1 and IgE in the BALF (P<0.05).

CONCLUSION

The inhalation of aerosolized anti-IL-1β IgY inhibits pathological responses in the pulmonary tissues of guinea pigs with allergic asthma. The inhibitory activity may be due to the decrease in the numbers of eosinophils and neutrophils and the reduced levels of inflammatory cytokines and IgE in the PB and BALF.

Optical diagnosis for lung cancer using multiphoton imaging

Currently, hematoxylin-eosin (H-E) stained histopathology is the golden standard for diagnosing lung cancer. This time-consuming procedure needs tissue biopsy, sample fixation, slicing, and labeling. Therefore, the availability of a noninvasive optical diagnosis that can obtain real-time analysis comparable to golden standard H-E stained histopathology will be of extraordinary benefit to the medical community. In this study, we investigated whether multiphoton imaging can make real-time optical diagnosis for normal and cancerous lung tissue, compared with H-E stained histopathology. In the normal lung tissue, we found that multiphoton imaging could display normal lung parenchyma composed of alveolar spaces separated by thin septa. In the cancerous lung tissue, multiphoton imaging clearly illustrated that cancer cells displayed marked cellular and nuclear pleomorphism. These cancer cells were characterized by irregular size and shape, enlarged nuclei, and increased nuclear-cytoplasmic ratio. All of these histopathological features of tissue architecture and cell morphology identified by multiphoton images were readily correlated with H-E staining images. All together, multiphoton imaging can make real-time optical diagnosis for lung cancer. This study provides the groundwork for further using multiphoton imaging to perform real-time noninvasive "optical biopsy" for lung cancer in the near future.

Antidiabetic effect of total flavonoids from Sanguis draxonis in type 2 diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Sanguis draxonis (SD) is a kind of red resin obtained from the wood of Dracaena cochinchinensis (Lour.) S. C. Chen (Dracaena cochinchinensis). It is a Chinese traditional herb that is prescribed for the handling of diabetic disorders, which is also supported by an array of scientific studies published in recent years. Although chemical constituents of this plant material have also been previously evaluated (Tang et al., 1995; Wei et al., 1998), it still remains poorly understood which constituent is the major contributor to its antidiabetic activities. Moreover, very little is known about the molecular mechanisms underlying antidiabetic activities of SD. Flavonoids exist at a high level in SD. The aim of this study is to evaluate the antidiabetic effects of total flavonoids from SD (SDF) in type 2 Diabetes mellitus (T2DM) rats.

MATERIALS AND METHODS

T2DM rats were induced by 4 weeks high-fat diet and a singular injection of streptozotocin (STZ) (35mg/kg). Then T2DM rats were treated with SDF for 21 days, using normal saline as the negative control. For comparison, a standard antidiabetic drug, metformin (200mg/kg), was used as a positive control. Three weeks later, relative biochemical indexes were determined and histopathological examinations were performed to assess the antidiabetic activities of SDF.

RESULTS

SDF not only exhibited a significant hypoglycemic activity, but also alleviated dyslipidemia, tissue steatosis, and oxidative stress associated with T2DM. Moreover, considerable pancreatic islet protecting effects could be observed after SDF treatment. Further investigations revealed a potential anti-inflammation activity of SDF by determining serum levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP).

CONCLUSIONS

This study demonstrates both hypoglycemic and hypolipidemic effects of SDF in T2DM rats, suggesting that flavonoids are the major active ingredients accounting for the antidiabetic activity of SD. Alleviating chronic inflammation responses and protecting pancreatic islets are possible mechanisms involved in the antidiabetic activity of SDF.

Elastin staining patterns in primary cicatricial alopecia

BACKGROUND

Most biopsy specimens of cicatricial (scarring) alopecia can be readily subclassified as lymphocytic versus neutrophilic, but specific diagnosis remains difficult, particularly when a late stage of the disease is sampled.

OBJECTIVE

We sought to document patterns of scarring highlighted by elastic tissue staining in primary cicatricial alopecia.

METHODS

We documented Verhoeff elastic van Gieson staining patterns in 58 routinely embedded (vertical) biopsy specimens of cicatricial alopecia. Patterns of fibrosis included perifollicular (wedge-shaped vs broad tree trunk-shaped) and diffuse. The patterns were compared against the diagnosis obtained by independent expert clinical review, including central centrifugal cicatricial alopecia (CCCA), lichen planopilaris, traction alopecia, frontal fibrosing alopecia, discoid lupus erythematosus, and tufted folliculitis.

RESULTS

Wedge-shaped perifollicular fibrosis was seen in lichen planopilaris but also in CCCA. Broad tree trunk-shaped perifollicular fibrosis was most commonly encountered in CCCA.

LIMITATIONS

The retrospective nature of the study precluded temporal staging of the disease process.

CONCLUSIONS

Patterns of fibrosis highlighted by elastin staining in primary cicatricial alopecia appear to be disease specific. Superficial wedge-shaped perifollicular fibrosis is associated with but may not be specific for lichen planopilaris. Broad tree trunk-like perifollicular fibrosis is specific for CCCA but not present in many cases. Elastin staining represents a useful ancillary study for the evaluation of late-stage scarring alopecia in routinely oriented punch biopsy specimens.

The receptor for activated complement factor 5 (C5aR) conveys myocardial ischemic damage by mediating neutrophil transmigration

Tissue loss after myocardial ischemia with reperfusion (MI/R) is in part conveyed by neutrophil recruitment to post-ischemic myocardium. Strategies to prevent reperfusion injury would help to limit myocardial damage. The receptor for activated complement factor 5 (C5aR) plays a prominent role in inflammation. We examine the effects of C5aR-deficiency on reperfusion injury after MI/R. C5aR(-/-)-mice and their C57BL/6- (WT) littermates underwent transient myocardial ischemia followed by different time points of reperfusion. Infarct size and leukocyte infiltration were determined. Expression of C5aR, inflammatory cytokines and adhesion molecules were analyzed by real-time RT-PCR. Leukocyte-endothelial interactions were assessed by low-shear adhesion- and transmigration-assays in vitro. Myocardial C5aR mRNA expression was 2.8-fold increased by ischemia. Infarct size per area-at-risk and leukocyte recruitment into infarctions were reduced in C5aR(-/-)-compared to WT-mice as well as in WT mice treated with the C5aR-antagonist JPE1375. IL-6, IL-1β, ICAM-1 and VCAM-1 expression were not different, while TNFα expression was reduced in C5aR(-/-)-mice after MI/R. In vitro, C5aR on leukocytes is required for effective transendothelial migration but not adhesion. Expression of MMP9 and JAM-A, molecules that are involved in leukocyte transmigration, were reduced in C5aR(-/-) mice in vivo. Genetic C5aR deficiency blunts the inflammatory response in murine MI/R resulting in reduced inflammatory cell recruitment, which is due to a C5aR-dependent effect on leukocyte transmigration across inflamed endothelium into the ischemic myocardium. This effect could be related to MMP9- and JAM-A expression in response to ischemia and reperfusion.