Adrenal Zona Fasciculata Nuclei of Gerbils Fed a High-Carbohydrate Diet: A Morphological and Textural Analysis
Year: 2025
Type: article
Abstract: The adrenal cortex plays a critical role in the regulation of metabolic and stress responses through secretion of glucocorticoids, particularly cortisol. In this study, we investigated morphological and textural changes in the nuclei of adrenal fasciculata zone cells in gerbils submitted to a high-carbohydrate diet (high fructose and glucose diet) and their correlation with cell hyperactivity. The gerbils were divided into two groups: a control group (CD) fed a standard diet and an experimental group fed a high-carbohydrate diet for 20 weeks (HCD). Adrenal tissue samples were processed for transmission electron microscopy (TEM) imaging and sections were viewed with an electron microscope (Zeiss Gemini SEM), focusing on the zona fasciculata. Zona fasciculata nuclei were individually processed and analyzed using the freely available software Fiji/ImageJ (https://imagej.net/FijI/Downloads) with pre-developed plugins and macros to determine the circularity (in shape descriptor), GLCM texture parameters, and fractal analysis. It was performed as previously described [1]. Statistical analyses were performed using GraphPad Prism software (version 10.00 for Windows, San Diego, CA, USA). Nuclei analysis revealed significant nuclear changes, including increased euchromatin content and reduced heterochromatin, indicating increased transcriptional activity in the experimental group. We also reported a significant decrease in nuclear surface area and circularity in the HCD group compared to CD. Nuclear contour irregularity has been detected in pathologies such as cancer [2], type 2 diabetes [3], and in gerbils subjected to nutritional stress [1]. Fractal analysis showed a decrease in fractal dimension, suggesting a reduction in chromatin complexity, whereas GLCM texture analysis showed an increase in angular second momentum (ASM) and a decrease in entropy, reflecting a greater uniformity of chromatin texture. These changes were associated with elevated cortisol levels in the high-carbohydrate diet group, thus confirming adrenal hyperactivity (Fig. 1). Principal component analysis (PCA) was performed on the eight studied variables to disentangle the associations between nuclear texture, shape, and chromatin quantity across gerbils. This analysis effectively distinguished between the control group and the gerbils subjected to a high-carbohydrate diet (Fig. 2). Notably, textural entropy, nuclear area and circularity, and fractal dimension were strongly associated with the control group, suggesting that these parameters may reflect stable nuclear organization under normal physiological conditions. In contrast, the high-carbohydrate diet group exhibited distinct nuclear texture features, with textural angular second moment (ASM) positively correlated with adrenal cortisol content. A. Representative photomicrographs of adrenal zona fasciculata nuclei. Control group (CD) and gerbils fed a high-carbohydrate diet (HCD) are shown. A single nucleus per photomicrograph was converted to an 8-bit grayscale format for GLCM analysis, a threshold method for heterochromatin quantification, and was binarized before calculating the fractal dimension. Scale bars: 2 µm. B. Effects of a high-carbohydrate diet on adrenal zona fasciculata nuclei and adrenal cortisol levels. The effects on the area, C. circularity, and D. heterochromatin area fraction of the gerbil adrenal zona fasciculata nuclei were analyzed. Additionally, the impact of diet on E. adrenal cortisol levels, F. fractal dimensions and GLCM texture parameters: G. angular second moment (ASM), H. inverse difference moment (IDM) and I. entropy were assessed. CD, control animals; HCD, animals fed a high-carbohydrate diet. Values are presented as mean ± SEM. Comparisons are statistically significant: ns (not significant) P ≥ 0.05; *P < 0.05; ***P < 0.001. The principal component analysis (PCA). CD control ,HCD animals subjected to high-carbohydrates diet . The variables were: AC (adrenal cortisol levels, Area, Circ (nuclear circularity), ENT (entropy), FD (fractal dimension), ASM (angular second moment), HAF (area fraction of heterochromatin) and IDM (inverse difference moment).
Source: Microscopy and Microanalysis
Language: English
Subfield: Endocrinology, Diabetes and Metabolism
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W4412909855