Histopathological effects of hypervitaminosis-D and the protective role of fetuin-A in renal, hepatic, and cardiac tissues in a murine model

Abstract

Hypervitaminosis D leads to toxic effects, including hypercalcemia, which can cause severe damage to various organs. Fetuin-A, a glycoprotein with anti-inflammatory properties, may protect tissues from such damage. This study explores the role of Fetuin-A in mitigating hypervitaminosis D-induced damage in renal, hepatic, and cardiac tissues. The objectives of this study were to: (1) Assess the extent of tissue damage from high-dose vitamin D in a murine model by examining the histopathological changes in liver, kidney and heart. (2) Investigate Fetuin-A's protective effect against this damage. Thirty-six albino rats were divided into four groups: (1) control, (2) vitamin D toxicity, (3) Fetuin-A + vitamin D, and (4) Fetuin-A only. Vitamin D was administered subcutaneously at 250 μg/20 g/day for 3 days. Fetuin-A was given at 100 μl/20 g, starting 7 days before vitamin D treatment. Histopathological analysis of liver, kidney, and heart tissues was performed using H&E and Alizarin Red staining and findings were analysed statistically. Vitamin D toxicity caused significant tissue damage, including apoptosis, inflammation, and calcification in the liver, kidneys, and heart. Pre-treatment with Fetuin-A reduced calcification and inflammation, preserving tissue architecture. Fetuin-A-only rats showed no damage or calcification. Fetuin-A provided statistically significant protection against vitamin D-induced damage, reducing oxidative stress and calcification in affected organs. These findings suggest Fetuin-A could be a potential therapeutic agent for hypervitaminosis D.

Keywords: Calcification; Fetuin-A; Hypervitaminosis D; Tissue damage; Vitamin D toxicity.

Fig. 1

Quantification of locomotor activity of the mice in Locomotor chamber.

Fig. 2

Histology of negative control mice liver (A) H&E showing normal architecture, (B) Alizarin Red showing no calcification, High Power, (C) Portal Vein diameter (widest area = 2.2mm) (× 40).

Fig. 3

Histology of mice liver after taking the toxic dose of Vit D (A–C) H&E showing apoptosis, inflammation, central vein dilatation and Kupffer cell hyperplasia, (D) Alizarin Red showing calcification in hepatocytes, (E) Portal Vein diameter (widest area = 6.2mm) High Power (× 40).

Fig. 4

Histology of mice liver after taking the Fetuin-A followed by toxic dose of Vit D, (A) H&E showing fatty degeneration of hepatocytes, occasional signet ring cells, Occasional cytoplasmic eosinophilia and sparce inflammation was also noted in the hepatocyte demonstrating reversible injury, (B) Alizarin Red showing sparse calcification in hepatocytes, (C) Portal Vein diameter (widest area = 3.2mm) (× 40).

Fig. 5

Histology of mice liver after taking the Fetuin-A only, (A) H&E showing mild fatty degeneration of hepatocytes, (B) Alizarin Red showing no calcification in hepatocytes, (C) Portal Vein diameter (widest area = 2.1mm) (× 40).

Fig. 6

Histology of negative control mice Kidney, (A) H&E showing normal kidney structure, (B) Alizarin Red showing no calcification, High Power (× 40).

Fig. 7

Histology of mice kidney after taking the toxic dose of Vit D, (A–C), H&E showing Glomerular shrinkage, wide Bowman’s capsule, inflammatory cell infiltrate, Hyaline casts, damaged tubular epithelium, Apoptosis, necrosis, calcification deposits, (D) Alizarin Red showing massive calcification, High Power (× 40).

Fig. 8

Histology of mice kidney after taking the Fetuin-A followed by toxic dose of Vit D, (A) H&E showing minimal inflammation, Epithelial degeneration, Hyaline casts, (B) Alizarin Red showing minimal calcification, High Power (× 40).

Fig. 9

Histology of mice kidney after taking the Fetuin-A only, (A) H&E showing normal kidney structure, (B) Alizarin Red showing no calcification, High Power (× 40).

Fig. 10

Histology of negative control mice heart, (A) H&E showing normal cardiac Fibers, (B) Alizarin Red showing no calcification, Low Power (× 10).

Fig. 11

Histology of mice heart after taking the toxic dose of Vit D, (A–C), H&E Showing Apoptotic Myocytes, dilated and congested capillaries, inflammatory cell infiltrate, damaged cardiac fibers, (D) Alizarin Red showing calcification, Low Power (× 10).

Fig. 12

Histology of mice heart after taking the Fetuin-A followed by toxic dose of Vit D, (A) H&E showing minimal inflammatory infiltrate of lymphocytes, (B) Alizarin Red showing minimal calcification, Low Power (× 10).

Fig. 13

Histology of mice heart after taking the Fetuin-A only, (A), H&E showing normal cardiac Fibers, (B) Alizarin Red showing no calcification, Low Power (× 10).