Reduced DNASE1 Gene Expression in Thyroid Autoimmunity

Abstract

The enzyme DNASE1 plays an important role in the hydrolysis of double-stranded DNA and might be related to autoimmunity. Therefore, the authors hypothesized that patients with autoimmune thyroid disease show a reduced expression of the DNASE1 gene. DNASE1 mRNA was quantitatively analyzed in 20 patients (10 with Hashimoto’s thyroiditis and 10 with Graves’ disease) and 20 age- and sex-matched healthy controls by real-time reverse transcription PCR in a lightcycler using SYBR-Green-format. For relative quantification, the mRNA ratio of the DNASE1 gene to the house keeping gene β2-MICROGLOBULIN was used. The house keeping gene was proved not to be regulated by autoimmune thyroid disease. The interassay coefficient of variation for patients and controls was 22.2% and 15.6%, respectively, suggesting good reproducibility of measurements. The mean expression of the DNASE1 mRNA in patients was 0.52±0.22 (range 0.18–0.99) and in controls 0.95±0.22 (0.66–1.43). The expression level of the DNASE1 gene was strongly decreased in patients, amounting only 54.7% of that in controls (p<0.001). The lowered expression level in patients was not related to age or sex. This study demonstrated for the first time a downregulation of the DNASE1 mRNA expression in patients with autoimmune thyroid disease. This might result in degrading less DNA from dying cells, thereby promoting the development of thyroid autoimmunity.

Key words

DNASE1 gene - autoimmune thyroid disease - relative quantification - real-time PCR - human

• References

• 1 Lacks SA. Deoxyribonuclease I in mammalian tissues. Specifity of inhibition by actin. J Biol Chem 1981; 256: 2644-2648
• 2 Yasuda T, Awazu S, Sato W, Iida R, Tanaka Y, Kishi K. Human genetically polymorphic deoxyribonuclease: purification, characterization, and multiplicity of urine deoxyribonuclease I. J Biochem (Tokyo) 1990; 108: 393-398
• 3 Yasuda T, Sawazaki K, Nadano D, Takeshita H, Nakanaga M, Kishi K. Human seminal deoxyribonuclease I (DNase I): purification, enzymological and immunological characterization and origin. Clin Chim Acta 1993; 218: 5-16
• 4 Yasuda T, Takeshita H, Nakajima T, Mogi K, Kaneko Y, Ueki M, Iida R, Kishi K. Abrupt pubertal elevation of DNase I gene expression in human pituitary glands of both sexes. FEBS Letters 2002; 510: 22-26
• 5 Kishi K, Yasuda T, Ikehara Y, Sawazaki K, Sato W, Iida R. Human serum deoxyribonuclease I (DNASE1) polymorphism: pattern similarities among isozymes from serum, urine, kidney, liver, and pancreas. Am J Hum Genet 2001; 47: 121-126
• 6 Oliveri M, Daga A, Lunardi C, Navone R, Millo R, Puccetti A. DNase I behaves as a transcription factor which modulates Fas expression in human cells. Eur J Immunol 2004; 34: 273-279
• 7 Napirei M, Karsunky H, Zevnik B, Stephan H, Mannherz HG, Moroy T. Features of systemic lupus erythematosus in Dnase1-deficient mice. Nat Genet 2000; 25: 177-181
• 8 Walport MJ. Lupus, DNase and defective disposal of cellular debris. Nat Genet 2000; 25: 135-136
• 9 Munoz LE, Herrmann M, Gaipl US. An impaired detection and clearance of dying cells can lead to the development of chronic autoimmunity. Z Rheumatol 2005; 64: 370-376
• 10 Yasuda T, Kishi K, Yanagawa Y, Yoshida A. Structure of the human deoxyribonuclease I (DNase I) gene: identification of the nucleotide substitution that generates its classical genetic polymorphism. Ann Hum Genet 1995; 59: 1-15
• 11 Kominato Y, Ueki M, Iida R, Kawai Y, Nakajima T, Makita C, Itoi M, Tajima Y, Kishi K, Yasuda T. Characterization of human deoxyribonuclease I gene (DNASE1) promoters reveals the utilization of two transcription-starting exons and the involvement of Sp1 in its transcriptional regulation. FEBS J 2006; 273: 3094-3105
• 12 Dittmar M, Poppe R, Bischofs C, Fredenhagen G, Kanitz M, Kahaly GJ. Impaired deoxyribonuclease activity in monoglandular and polyglandular autoimmunity. Exp Clin Endocrinol Diabetes 2007; 115: 387-391
• 13 Dittmar M, Bischofs C, Matheis N, Poppe R, Kahaly GJ. A novel mutation in the DNASE1 gene is related with protein instability and decreased enzyme activity in thyroid autoimmunity. J Autoimmun 2009; 32: 7-13
• 14 Tomer Y, Davies TF. Infection, thyroid disease, and autoimmunity. Endocr Rev 1993; 14: 107-120
• 15 Dittmar M, Kahaly GJ. Immunoregulatory and susceptibility genes in thyroid and polyglandular autoimmunity. Thyroid 2005; 15: 239-250
• 16 Huber A, Menconi F, Corathers S, Jacobson EM, Tomer Y. Joint genetic susceptibility to type 1 diabetes and autoimmune thyroiditis: from epidemiology to mechanisms. Endocr Rev 2008; 29: 697-725
• 17 Dultz G, Matheis N, Dittmar M, Bender K, Röhrig B, Kahaly GJ. The protein tyrosine phosphatase non-receptor type 22 C1858T polymorphism is a joint susceptibility locus for immunthyroiditis and autoimmune diabetes. Thyroid 2009; 19: 143-148
• 18 Peitsch MC, Polzar B, Stephan H, Crompton T, McDonald HR, Mannherz HG, Tschopp J. Characterization of the endogenous deoxyribonuclease involved in nuclear DNA degradation during apoptosis (programmed cell death). EMBO J 1993; 12: 371-377
• 19 Oliveri M, Daga A, Cantoni C, Lunardi C, Millo R, Puccetti A. DNase I mediates internucleosomal DNA degradation in human cells undergoing drug-induced apoptosis. Eur J Immunol 2001; 31: 743-751
• 20 Martínez Valle F, Balada E, Ordi-Ros J, Vilardell-Tarres M. DNase 1 and systemic lupus erythematosus. Autoimmun Rev 2008; 7: 359-363
• 21 Herrmann M, Voll RE, Kalden JR. Etiopathogenesis of systemic lupus erythematosus. Immunol Today 2000; 21: 424-426
• 22 Feng XB, Shen N, Qian J, Sun L, Hua J, Chen SL. Single nucleotide polymorphisms of deoxyribonuclease I and their expression in Chinese systemic lupus erythematosus patients. Chinese Med J 2004; 117: 1670-1676
• 23 Yasuda T, Takeshita H, Ueki M, Iida R, Nakajima T, Mori S, Mogi K, Kaneko Y, Kishi K. Tissue-specific in vivo inhibition of DNase I gene expression by somatostatin. Biochemical and Biophysical Res Commun 2001; 283: 287-291
• 24 Lu SC, Shih CH, Liao TH. Expression of DNase I in rat parotid gland and small intestine is regulated by starvation and refeeding. J Nutr 2003; 133: 71-74
• 25 Kominato Y, Iida R, Nakajima T, Tajima Y, Takagi R, Makita C, Kishi K, Ueki M, Kawai Y, Yasuda T. Hypoxia induces upregulation of the deoxyribonuclease I gene in human pancreatic cancer cell line QGP-1. Biochim Biophys Acta. 2007 1770. 1567-1575