First Author | Lam QL | Year | 2010 |
Journal | Proc Natl Acad Sci U S A | Volume | 107 |
Issue | 31 | Pages | 13812-7 |
PubMed ID | 20643953 | Mgi Jnum | J:163456 |
Mgi Id | MGI:4822068 | Doi | 10.1073/pnas.1004185107 |
Citation | Lam QL, et al. (2010) Leptin signaling maintains B-cell homeostasis via induction of Bcl-2 and Cyclin D1. Proc Natl Acad Sci U S A 107(31):13812-7 |
abstractText | Regulation of apoptosis and cell cycle progression plays an essential role in the maintenance of B-cell homeostasis, because a fine balance of survival and expansion is critical for preventing lymphocytic disorders. Although remarkable progress in understanding B-cell development has been achieved, much less is known concerning niches that are critical to the maintenance of B-cell homeostasis. Leptin has recently been recognized to be important for modulating the immune responses, but it has remained unclear how leptin signaling influences B-cell physiology. A variety of lymphocytic malignancies have been reported to be linked to leptin, and therefore it is necessary to elucidate the mechanisms involved. Here we demonstrate that leptin promotes B-cell homeostasis by inhibiting apoptosis and by inducing cell cycle entry through the activation of expressions of B-cell CLL/lymphoma 2 (Bcl-2) and cyclin D1. We further show that leptin can induce Bcl-2 and cyclin D1 expression by two pathways, including the direct activation of their promoters and suppression of microRNAs (miRNAs) that target their putative 3'untranslated regions. Amplification of these leptin-modulated miRNAs inhibited B lymphoma cell growth. These findings provide insights into mechanisms for leptin regulation of the humoral immune system and suggest new therapeutic strategies for leptin receptor expressing malignancies. |