Effect of Zbtb33 gene knockout and bacterial lipopolysaccharide on home cage behavior in mice

The Zbtb33 gene encodes the bimodal transcriptional repressor Kaiso, which causes epigenetic repression of genes by binding to methylated mCpG islets in the promoters of the genes. Despite the fact that Kaiso is intensively expressed in the central nervous system, its participation in the regulation of behavior is still poorly understood. Only the participation of Kaiso in the regulation of the behavioral response to emotional stress in the open field and forced swimming tests has been shown. The aim of this study is to elucidate the role that Kaiso plays in regulating daily activity, as well as the behavioral response to stimulation of nonspecific immunity. Experiments were performed on adult male mice with Zbtb33 gene knockout (KO) and animals of the C57BL/6 line (wild type, WT). All animals were 11 weeks old, weighed 26 ± 1 g and had SPF (specific pathogen free) status throughout the experiment. The animals of each genotype were divided into three weighted groups of 8 animals each. Initially, the daily dynamics of motor activity, sleep, food and water intake of intact animals was measured using the PhenoMaster software-hardware complex. The animals of each group were then injected with saline (control), 0.1 or 1.0 mg/kg of bacterial lipopolysaccharide (LPS) dissolved in saline, and again measured for their daily activity, food and water intake. Intact KO and WT mice did not differ in the average daily motor activity and sleep duration. However, intact KO mice were less active in the dark time, and also consumed less food and water as compared to intact WT animals. LPS at both doses suppressed motor activity, prolonged sleep duration and caused anorexia in mice of both genotypes. However, the effect of low dose of LPS (0.1 mg/kg) on the food and water intake was more pronounced in KO mice than in WT animals. The results shed light on the biological significance of the Kaiso gene and serve as a justification for the necessity of the normal functioning of this gene in natural populations.

Kaiso gene, knockout mice, PhenoMaster, home cage, LPS

1. Bali P., Im H.I., Kenny P.J. Methylation, memory and addiction. Epigenetics. 2011;6:671­674.

2. Bird A. DNA methylation patterns and epigenetic memory. Genes Dev. 2002;16:6­21.

3. Bogdanovic O., Veenstra G.J. DNA methylation and methyl­CpG binding proteins: developmental requirements and functions. Chromosoma. 2009;118:549­565.

4. Dantzer R. Cytokine, sickness behavior, and depression. Immunol. Allergy Clin. North Am. 2009;29:247­264.

5. Della Ragione F., Tiunova A., Vacca M., Strazzullo M., González E., Armstrong J., Valero R., Campanile C., Pineda M., Hulten M., Monros E., D’Esposito M., Prokhortchouk E. The X­linked methyl binding protein gene Kaiso is highly expressed in brain but is not mutated in Rett syndrome patients. Gene. 2006;373:83­89.

6. Filion G.J., Zhenilo S., Salozhin S., Yamada D., Prokhortchouk E., Defossez P.A. A family of human zinc finger proteins that bind methylated DNA and repress transcription. Mol. Cell. Biol. 2006;26:169­181.

7. Jiang Y., Matevossian A., Guo Y., Akbarian S. Setdb1­mediated histone H3K9 hypermethylation in neurons worsens the neurological phenotype of Mecp2­deficient mice. Neuropharmacology. 2011;60: 1088­1097.

8. Klose R.J., Bird A.P. Genomic DNA methylation: the mark and its mediators. Trends Biochem. Sci. 2006;31:89­97.

9. Kondo M., Gray L.J., Pelka G.J., Christodoulou J., Tam P.P.L., Hannan A.J. Environmental enrichment ameliorates a motor coordination deficit in a mouse model of Rett syndrome – Mecp2 gene dosage effects and BDNF expression. Eur. J. Neurosci. 2008;27:3342­3350. DOI 10.1111/j.1460­9568.2008.06305.x.

10. Korostina V.S., Kulikov A.V. Behavioral phenotyping of Kaiso­deficient mice. Vavilovskii Zhurnal Genetiki i Selektsii = Vavilov Journal of Genetics and Breeding. 2015;19(4):399­403. DOI 10.18699/VJ15.051. (in Russian)

11. Kulikov A.V., Korostina V.S., Kulikova E.A., Fursenko D.V., Akulov A.E., Moshkin M.P., Prokhortchouk E.B. Knockout Zbtb33 gene results in an increased locomotion, exploration and pre­pulse inhibition in mice. Behav. Brain Res. 2016;297:76­83.

12. Lubin F.D., Gupta S., Parrish R.R., Grissom N.M., Davis R.L. Epigenetic mechanisms: critical contributors to long­term memory formation. Neuroscientist. 2011;17:616­632.

13. Matt S.M., Lawson M.A., Johnson R.W. Aging and peripheral lipopolysaccharide can modulate epigenetic regulators and decrease IL­1β promoter DNA methylation in microglia. Neurobiol. Aging. 2016; 47:1­9.

14. Prokhortchouk A., Sansom O., Selfridge J., Caballero I.M., Salozhin S., Aithozhina D., Cerchietti L., Meng F.G., Augenlicht L.H., Mariadason J.M., Hendrich B., Melnick A., Prokhortchouk E., Clarke A., Bird A. Kaiso­deficient mice show resistance to intestinal cancer. Mol. Cell. Biol. 2006;26:199­208.

15. Shumskaya V.S., Zhigalova N.A., Prokhorchouk A.V., Prokhorchouk E.B. Distribution of Kaiso protein in mouse tissues. Histochem. Cell Biol. 2015;143(1):29­43.

16. Wade P.A. Methyl CpG­binding proteins and transcriptional repression. BioEssays. 2001;23:1131­1137.