Journal of Histochemistry & Cytochemistry最新文献

Photodynamic therapy (PDT) is an effective and cosmetically beneficial treatment of low-risk basal cell carcinomas (BCCs). To optimize PDT response, it is important to correctly select tumors. We sought to find markers that could identify such tumors beyond contributions from clinical and histological examination. Studies have shown that β-catenin, E-cadherin, and α-smooth muscle actin (SMA) expression can indicate BCC aggressiveness/BCC invasiveness. We wanted to use these markers in an explorative study to investigate whether they were differently expressed among non-recurring compared with recurring BCCs, to evaluate their ability of predicting PDT outcome. Fifty-two BCCs were stained with antibodies against β-catenin, E-cadherin, and α-SMA, and evaluated using immunoreactive score (IRS), subcellular localization, and stromal protein expression. Results showed that IRS of E-cadherin was significantly different among recurring compared with non-recurring BCCs and with area under a receiver operating characteristic curve of 0.71 (95% confidence interval: 0.56-0.86, p=0.025). Stromal β-catenin expression significantly increased among recurring BCCs. Some recurring BCCs had intense expression in the deep invading tumor edge. In conclusion, E-cadherin, and stromal and deep edge β-catenin expression were most prominent in BCCs that recurred post-PDT, suggesting they could potentially predict PDT outcome. Further studies are needed to investigate whether these results are of clinical value.

Multiplex immunofluorescence (MxIF) images provide detailed information of cell composition and spatial context for biomedical research. However, compromised data quality could lead to research biases. Comprehensive image quality checking (QC) is essential for reliable downstream analysis. As a reliable and specific staining of cell nuclei, 4',6-diamidino-2-phenylindole (DAPI) signals were used as references for tissue localization and auto-focusing across MxIF staining-scanning-bleaching iterations and could potentially be reused for QC. To confirm the feasibility of using DAPI as QC reference, pixel-level DAPI values were extracted to calculate signal fluctuations and tissue content similarities in staining-scanning-bleaching iterations for identifying quality issues. Concordance between automatic quantification and human experts' annotations were evaluated on a data set consisting of 348 fields of view (FOVs) with 45 immune and tumor cell markers. Cell distribution differences between subsets of QC-pass vs QC-failed FOVs were compared to investigate the downstream effects. Results showed that 87.3% FOVs with tissue damage and 73.4% of artifacts were identified. QC-failed FOVs showed elevated regional gathering in cellular feature space compared with the QC-pass FOVs. Our results supported that DAPI signals could be used as references for MxIF image QC, and low-quality FOVs identified by our method must be cautiously considered for downstream analyses.

Giant cell tumors of bone (GCTBs) are locally aggressive tumors with the histological features of giant cells and stromal cells. Denosumab is a human monoclonal antibody that binds to the cytokine receptor activator of nuclear factor-kappa B ligand (RANKL). RANKL inhibition blocks tumor-induced osteoclastogenesis, and survival, and is used to treat unresectable GCTBs. Denosumab treatment induces osteogenic differentiation of GCTB cells. In this study, the expression of RANKL, special AT-rich sequence-binding protein 2 (SATB2, a marker of osteoblast differentiation), and sclerostin/SOST (a marker of mature osteocytes) was analyzed before and after treatment with denosumab in six cases of GCTB. Denosumab therapy was administered a mean of five times over a mean 93.5-day period. Before denosumab treatment, RANKL expression was observed in one of six cases. After denosumab therapy, spindle-like cells devoid of giant cell aggregation were RANKL-positive in four of six cases. Bone matrix-embedded osteocyte markers were observed, although RANKL was not expressed. Osteocyte-like cells were confirmed to have mutations, as identified using mutation-specific antibodies. Our study results suggest that treatment of GCTBs with denosumab results in osteoblast-osteocyte differentiation. Denosumab played a role in the suppression of tumor activity via inhibition of the RANK-RANKL pathway, which triggers osteoclast precursors to differentiate into osteoclasts.

Tau phosphorylation, aggregation, and toxicity are the main drivers of neurodegeneration in multiple tauopathies, including Alzheimer's disease (AD) and frontotemporal lobar degeneration with tau. Although aggregation and amyloid formation are often assumed to be synonymous, the ability of tau aggregates in different diseases to form amyloids in vivo has not been systematically studied. We used the amyloid dye Thioflavin S to look at tau aggregates in mixed tauopathies such as AD and primary age-related tauopathy, as well as pure 3R or 4R tauopathies such as Pick's disease, progressive supranuclear palsy, and corticobasal degeneration. We found that aggregates of tau protein only form thioflavin-positive amyloids in mixed (3R/4R), but not pure (3R or 4R), tauopathies. Interestingly, neither astrocytic nor neuronal tau pathology was thioflavin-positive in pure tauopathies. As most current positron emission tomography tracers are based on thioflavin derivatives, this suggests that they may be more useful for differential diagnosis than the identification of a general tauopathy. Our findings also suggest that thioflavin staining may have utility as an alternative to traditional antibody staining for distinguishing between tau aggregates in patients with multiple pathologies and that the mechanisms for tau toxicity may differ between different tauopathies.

Neutral buffered formalin (NBF) is the most common fixative in clinical applications. However, NBF damages proteins and nucleic acids, limiting the quality of proteomic and nucleic acid-based assays. Prior studies have demonstrated that BE70, a fixative of buffered 70% ethanol, has many benefits over NBF but the degradation of proteins and nucleic acids in archival paraffin blocks remain a challenge. Thus, we evaluated the addition of guanidinium salts to BE70 with the hypothesis that this may protect RNA and protein. Guanidinium salt supplemented BE70 (BE70G)-fixed tissue is comparable with that of BE70 via histology and immunohistochemistry. Western blot analysis also revealed that HSP70, AKT, and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression signals in BE70G-fixed tissue were higher than those in BE70-fixed tissue. The quality of nucleic acids extracted from BE70G-fixed, paraffin-embedded tissue was also superior, and BE70G provides improved protein and RNA quality at shorter fixation times than its predecessors. The degradation of proteins, AKT and GAPDH, in archival tissue blocks is also decreased with the addition of guanidinium salt to BE70. In conclusion, BE70G fixative improves the quality of molecular analysis with more rapid fixation of tissue and enhanced long-term storage of paraffin blocks at room temperature for evaluation of protein epitopes.

Pressure ulcers represent a crucial clinical problem, especially in hospitalized patients. Ischemia-reperfusion (I-R) is an important cause of these lesions. Natural killer (NK), invariant NK T (iNKT), and dendritic epidermal T-cells, which express the natural killer group 2, member D (NKG2D) receptor, have been reported to have physiological roles in skin tissue repair and wound healing. However, a role for NKG2D-NKG2D ligand interactions in I-R-induced skin injury has not been determined. Using a murine pressure ulcer model, we demonstrated that I-R-induced ulcers in NKG2D-deficient mice were larger than those in wild-type or T-cell receptor δ knockout mice. Histopathological evaluation revealed that accumulation of macrophages and neutrophils at the peripheral deep dermis and subcutaneous tissue of the ulcers was enhanced in NKG2D-deficient mice. Rae-1 mRNA, which encodes an NKG2D ligand, was induced, and RAE-1 protein was detected immunohistochemically in fibroblasts and inflammatory cells in the dermis after reperfusion. RAE-1 expression was also increased in primary mouse fibroblasts treated with sodium arsenite. These results suggested that NKG2D ligand expression was induced by oxidative stress after I-R injury and support a putative role for this ligand in wound repair. Furthermore, the influx of NKG2D-positive cells at I-R sites may mitigate pressure ulcers via NKG2D-NKG2D ligand interactions.

We tried to prevent nonspecific nuclear staining (NS-NS) of picrosirius red (PSR) staining by treating the specimens with one of the heteropoly acids phosphotungstic acid (PTA). We analyzed a total of 35 cases of non-cancerous liver tissue for fibrosis and NS-NS under PSR-alone, phosphomolybdic acid (PMA)-pretreated PSR (PMA + PSR), or PTA-pretreated PSR (PTA + PSR) condition. In addition, we analyzed the photosensitivity of PMA or PTA single stain specimens. PTA + PSR significantly suppressed NS-NS compared with PSR. The color of the specimens did not change into blue by 30 times the exposure to whole slide scanner (WSS) light. The PTA + PSR condition showed the highest correlation with the Ishak score (pathological evaluation of liver fibrosis) compared with other conditions. Furthermore, Sirius Red-positive percentage (SRP%) in PSR was increased in the NS-NS observed cases. SRP% in PMA + PSR was significantly affected by WSS light exposure time. Moreover, the deposition of non-polarized PSR-stained substances (NP-PSR⁺S) clinging to the collagen fibers potentially explains why SRP% seemed bigger under PSR than PTA + PSR. Our protocol enabled us to analyze the whole slide image of PSR staining by high magnification, which would contribute to the accurate analysis of collagen amount in the tissue sections.

This commentary briefly reviews the background for the development of the horseradish peroxidase-diaminobenzidine tetrahydrochloride histochemical method originally described by Graham and Karnovsky in their citation classic, reprinted in full in this issue of Journal of Histochemistry & Cytochemistry. Some of the method's subsequent applications, including its use as a macromolecular tracer for kidney glomerular permeability and use in immunoelectron microscopy and other immunoassays, are also discussed.

Immunocytochemical (ICC) techniques are frequently used in basic and clinical research. Here, we focus on the importance of using antisera/antibodies at optimal dilutions to achieve specificity and reduce costs. Unfortunately, the basic principle, the necessity to test method specificity of the staining by a series of increasing dilutions of primary antiserum/antibodies, is only occasionally seen in papers using ICC. Many researchers rely on the company's information or others' published data. In this study, we show examples with monoclonal antibodies used in the peroxidase-based ICC technique in mouse and guinea pig brain sections. We show images of ICC staining of phospho-S129 alpha-synuclein in A53T mice and NeuN in guinea pig brains and demonstrate that optimal staining with them can be achieved at least at two to three orders of magnitude higher dilutions than generally used in the literature. We strongly recommend that when antisera/antibodies are used for the first time in any laboratory, independent of what the manufacturer or vendor recommends or are found in the literature, a dilution curve should be set up to identify the optimal dilution. This practice provides not only the highest specificity but is also an economic approach.