Light-Induced Functional Pinealectomy. Effect on the Thymus of C57BL/6 Mice

S V Michurina; S M Miroshnichenko; A E Serykh; I Yu Ishchenko; A Yu Letyagin; E L Zavjalov

doi:10.1007/s10517-022-05665-2

Light-Induced Functional Pinealectomy. Effect on the Thymus of C57BL/6 Mice

Bull Exp Biol Med. 2022 Nov;174(1):152-158. doi: 10.1007/s10517-022-05665-2. Epub 2022 Nov 28.

Authors

S V Michurina¹, S M Miroshnichenko^{2

3}, A E Serykh^{2

4}, I Yu Ishchenko², A Yu Letyagin², E L Zavjalov⁵

Affiliations

¹ Research Institute of Clinical and Experimental Lymphology - Affiliated Branch of Federal Research Center Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia. michurinasv3000@gmail.com.
² Research Institute of Clinical and Experimental Lymphology - Affiliated Branch of Federal Research Center Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia.
³ Research Institute of Biochemistry, Federal Research Center of Fundamental and Translational Medicine, Novosibirsk, Russia.
⁴ Research Institute of Experimental and Clinical Medicine, Federal Research Center of Fundamental and Translational Medicine, Novosibirsk, Russia.
⁵ Federal Research Center Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia.

PMID: 36437341
DOI: 10.1007/s10517-022-05665-2

Abstract

Light-induced functional pinealectomy was simulated in C57BL/6 mice by 14-day exposure to constant lighting. Immunophenotyping of CD3^hi and CD3^low thymocytes was performed by staining with CD3-APC antibodies followed by flow cytofluorometry. To study the cell cycle distribution of thymus cells, the content of intracellular DNA was measured by the level PI inclusion. In animals with light-induced functional pinealectomy, blood leukocyte content, the relative number of CD3^low and CD3^hi T cells in the thymus, and the ratio of CD3^low/CD3^hi thymocytes decreased. The number of G0/G1-phase thymus cells (non-dividing cells) increased and the content of S-phase cells (division phase) decreased. Continuous lighting stimulated the development of thymocyte apoptosis. The results obtained indicate that prolonged 24-h illumination inhibits differentiation and maturation of young CD3^low thymocytes into mature CD3^hi forms and leads to the development of T-cell apoptosis in the thymus and, as a consequence, to leukopenia.

Keywords: CD3hi thymocytes; CD3low thymocytes; continuous lighting; leukopenia; light-induced functional pinealectomy.

MeSH terms

Animals
Mice
Mice, Inbred C57BL
Pinealectomy* / adverse effects
Thymus Gland* / pathology
Thymus Gland* / physiology