Preparing Paraffin Tissue Sections for Staining

In Vivo Anti-Inflammatory and Antinociceptive Activities of Black Elder (Sambucus nigra L.) Fruit and Flower Extracts

Sambucus nigra L. (S. nigra, SN) or black elder is a traditional medicinal plant widely used worldwide for therapeutic and dietary purposes. The aim of the current study was to investigate the anti-inflammatory and antinociceptive activities of black elder fruit and flower extracts (SNFrE and SNFlE, respectively). The primary polyphenol constituents in the flower extract were flavonoids and phenolic acids, while anthocyanins were the main components in the fruit extract. SNFrE revealed pronounced and dose-dependent in vivo anti-inflammatory activity assessed by the cotton pellet-induced granuloma test. Doses of 10, 20, and 50 mg/kg BW of SNFrE reduced the weight of induced granuloma in rats by 20.3%, 20.5%, and 28.4%, respectively. At the highest dose (50 mg/kg BW), SNFrE had significant (p < 0.01) anti-inflammatory activity comparable to that of diclofenac, the reference compound used (10 mg/kg BW). In addition, the in vivo antinociceptive activity of the extracts in mice was estimated using the acetic-acid-induced writhing test. Both extracts at doses of 50 mg/kg BW inhibited the abdominal contractions induced by the acetic acid significantly comparing to the control group (p < 0.01). Our findings indicate that black elder extracts and particularly SNFrE possess anti-inflammatory and antinociceptive activities, providing experimental evidence for the use of S. nigra in traditional medicine.

Distinct mesenchymal cell states mediate prostate cancer progression

In the complex tumor microenvironment (TME), mesenchymal cells are key players, yet their specific roles in prostate cancer (PCa) progression remain to be fully deciphered. This study employs single-cell RNA sequencing to delineate molecular changes in tumor stroma that influence PCa progression and metastasis. Analyzing mesenchymal cells from four genetically engineered mouse models (GEMMs) and correlating these findings with human tumors, we identify eight stromal cell populations with distinct transcriptional identities consistent across both species. Notably, stromal signatures in advanced mouse disease reflect those in human bone metastases, highlighting periostin's role in invasion and differentiation. From these insights, we derive a gene signature that predicts metastatic progression in localized disease beyond traditional Gleason scores. Our results illuminate the critical influence of stromal dynamics on PCa progression, suggesting new prognostic tools and therapeutic targets.

Epigenomic analysis of formalin-fixed paraffin-embedded samples by CUT&Tag

For more than a century, formalin-fixed paraffin-embedded (FFPE) sample preparation has been the preferred method for long-term preservation of biological material. However, the use of FFPE samples for epigenomic studies has been difficult because of chromatin damage from long exposure to high concentrations of formaldehyde. Previously, we introduced Cleavage Under Targeted Accessible Chromatin (CUTAC), an antibody-targeted chromatin accessibility mapping protocol based on CUT&Tag. Here we show that simple modifications of our CUTAC protocol either in single tubes or directly on slides produce high-resolution maps of paused RNA Polymerase II at enhancers and promoters using FFPE samples. We find that transcriptional regulatory element differences produced by FFPE-CUTAC distinguish between mouse brain tumors and identify and map regulatory element markers with high confidence and precision, including microRNAs not detectable by RNA-seq. Our simple workflows make possible affordable epigenomic profiling of archived biological samples for biomarker identification, clinical applications and retrospective studies.

Distinct mesenchymal cell states mediate prostate cancer progression

Alterations in tumor stroma influence prostate cancer progression and metastatic potential. However, the molecular underpinnings of this stromal-epithelial crosstalk are largely unknown. Here, we compare mesenchymal cells from four genetically engineered mouse models (GEMMs) of prostate cancer representing different stages of the disease to their wild-type (WT) counterparts by single-cell RNA sequencing (scRNA-seq) and, ultimately, to human tumors with comparable genotypes. We identified 8 transcriptionally and functionally distinct stromal populations responsible for common and GEMM-specific transcriptional programs. We show that stromal responses are conserved in mouse models and human prostate cancers with the same genomic alterations. We noted striking similarities between the transcriptional profiles of the stroma of murine models of advanced disease and those of of human prostate cancer bone metastases. These profiles were then used to build a robust gene signature that can predict metastatic progression in prostate cancer patients with localized disease and is also associated with progression-free survival independent of Gleason score. Taken together, this offers new evidence that stromal microenvironment mediates prostate cancer progression, further identifying tissue-based biomarkers and potential therapeutic targets of aggressive and metastatic disease.

Active immunotherapy reduces NOTCH3 deposition in brain capillaries in a CADASIL mouse model

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common monogenic form of familial small vessel disease; no preventive or curative therapy is available. CADASIL is caused by mutations in the NOTCH3 gene, resulting in a mutated NOTCH3 receptor, with aggregation of the NOTCH3 extracellular domain (ECD) around vascular smooth muscle cells. In this study, we have developed a novel active immunization therapy specifically targeting CADASIL-like aggregated NOTCH3 ECD. Immunizing CADASIL TgN3R182C¹⁵⁰ mice with aggregates composed of CADASIL-R133C mutated and wild-type EGF_1-5 repeats for a total of 4 months resulted in a marked reduction (38-48%) in NOTCH3 deposition around brain capillaries, increased microglia activation and lowered serum levels of NOTCH3 ECD. Active immunization did not impact body weight, general behavior, the number and integrity of vascular smooth muscle cells in the retina, neuronal survival, or inflammation or the renal system, suggesting that the therapy is tolerable. This is the first therapeutic study reporting a successful reduction of NOTCH3 accumulation in a CADASIL mouse model supporting further development towards clinical application for the benefit of CADASIL patients.

The effect of acidifier supplementation on egg production performance and intestinal histology of Japanese quail (Coturnix japonica)

BACKGROUND

Acidifier are substances with antibacterial, antifungal, antimicrobial, performance and health benefits that are frequently employed in feed acidification, especially in poultry diet. Meanwhile, the most important factor for acidifier efficiency is the proportion of different acids in the final product.

OBJECTIVES

This study aimed to investigate the effect of dietary supplementation of a commercial acidifier on egg production and histology of the small intestine in laying Japanese quail.

METHODS

One-hundred and sixty female quails at 15 weeks of age were divided into four groups and fed basal diet supplemented with different levels of acidifier (0, 1, 2 and 3 gr acidifier/kg of basal diet) for 8 weeks. Egg production, egg quality attributes and body weight (BW) were measured every 2 weeks. Histology of the small intestine and bacterial population of cecum as well as pH of crop, duodenum, jejunum, ileum and cecum contents were also investigated at the end of the experiment.

RESULTS

Feed conversion ratio (FCR), yolk height, shell thickness, pH of the duodenum, jejunum, ileum, cecum; duodenum, villus width (VW), villus height (VH), crypt depth (CD); jejunum VH, VW and ileum VH to CD ratio (VCR) were linearly improved by the increasing levels of acidifier supplementation (P < 0.05). Duodenum VH increased in a linear and quadratic manner in response to increasing levels of acidifier. Egg weight, yolk diameter, jejunum CD, ileum CD, ileum VW, duodenum CD and jejunum VCR quadratically improved by grading levels of acidifier (P < 0.01). BW, albumen height, Haugh unit, ileum VH and ileum VCR were cubically enhanced (P < 0.05). Acidifier supplementation enhanced egg production, FCR, jejunum, ileum and cecum pH and VH, CD and VW of duodenum and jejunum, compared to the control group (P < 0.05); however, dietary acidifier did not affect egg mass, gizzard pH, ileum VH and bacterial count of the cecum (P > 0.05).

CONCLUSIONS

In conclusion, as calculated, the supplementation of 1 and 2.6 g acidifier per kg of diet was associated with beneficial effects on egg production and quality, gastrointestinal tract pH and histology of the small intestine in laying quails.

Cell Staining

When labeled antibodies are used to detect antigens in cells or tissues, several characteristics of an antigen can be readily determined. Most importantly, cell staining will show both the presence and subcellular localization of an antigen. Double-labeling techniques permit the simultaneous detection of two antigens, allowing comparisons of the relative distribution of different antigens. Many cell-staining methods can also be used in conjunction with conventional histological stains and autoradiographic methods to compare the localization of the antigen with other markers. Cell staining can also be used in pathology studies for determining such variables as the type of infectious organism, the progenitor of a neoplastic cell, or the presence of an inflammatory response. With certain modifications, the procedure can be used to purify cells on the basis of the antigenic composition of their cell surface. Cell staining is a versatile technique and, if the antigen is highly localized, can detect as few as a thousand antigen molecules in a cell or tissue. In some circumstances, cell staining may also be used to determine the approximate concentration of an antigen. Improvements in antibody labeling methods, microscopes, cameras, and image analyzers are rapidly extending the sensitivity of cell-staining procedures and are making these techniques more quantitative. Even without these improvements, cell staining can yield important qualitative and semiquantitative data. This introduction describes protocols for cell staining techniques and includes a discussion of major constraints, antibody selection, and troubleshooting.