Laughter regulates gene expression in patients with type 2 diabetes.
BACKGROUND
Positive emotions influence endocrinological and immunological response. This study examined the effect of laughter,as an expression of positive emotion, in terms of gene expression changes.


METHODS
Using a microarray technique, we analyzed the changes in expression of 18,716 genes from peripheral blood leukocytes in patients with type 2 diabetes, which were induced by laughter.


RESULTS
Of the 18,716 genes, 23 genes showed significantly different expression changes after listening to the comic story compared to the lecture. Eight were relatively upregulated and 15 were downregulated 1.5 h after the laughing episode. However, these genes did not include genes that are directly involved in blood glucose metabolism. Among the 23 genes discriminated, all 4 genes encoding proteins involved in the immune response and all 4 signal transduction genes were downregulated. Moreover, it is noteworthy that 5 of the 8 relatively upregulated genes were related to the cell cycle, apoptosis, and cell adhesion.


CONCLUSIONS
We demonstrated that laughter, which is an expression of positive emotion, is linked to gene expression. However, the finding of this study does not allow reasonable interpretation for the regulation of gene expression by laughter. A more focused study is needed that may identify the candidate genes for the association between physical condition and positive emotion.
Hayashi
Takashi
T
Foundation for Advancement of International Science, Bio-Laboratory, Tsukuba, Japan. hayashi@fais.or.jp
Urayama
Osamu
O
Kawai
Koichi
K
Hayashi
Keiko
K
Iwanaga
Shizuko
S
Ohta
Masayuki
M
Saito
Toshiro
T
Murakami
Kazuo
K
D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D015536:Down-Regulation; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007845:Laughter; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D015398:Signal Transduction