γ-ray Induced Haptoglobin Expression And Its Preliminary Functional

Early dose estimation plays a key role in treatment of acute radiation injury. To explore early diagnostic biomarkers, serum proteomic changes of irradiated mice were investigated using 2-DE and MS approaches. Results showed that serum haptoglobin was up-regulated in 8Gy y-ray irradiated mice. γ-ray induced haptoglobin expression and its preliminary function were studied. Data are as follows:1. Serum changes of haptolgobin in y-ray irradiated mice. Serum haptolgobin level was increased in a time- and dose- dependent manner. The results implies that serum haptoglobin may be an early biomarker for acute radiation injury.2. Changes of haptoglobin mRNA level in hematopoietic and immune tissue. Results showed that haptoglobin mRNA level was up-regulated in bone marrow, thymus, spleen, liver, lung, and intestine of y-ray irradiated mice.3. Mechanism of y-ray induced haptoglobin expression. Synthesis of haptoglobin was induced by y-ray in a dose- and time-dependent manner. Combination of EMSA and super shift assay demonstrated that promoter region B and C, as well as transcription factors stat3 and C/EBPβ-LIP, were involved in y-ray induced haptoglobin expression in THP-1 cells.4. Preliminary functional research on haptoglobin in y-ray induced cell injury. Haptoglobin was expressed only in some bone marrow and blood cells. Cell population expressing haptoglobin was increased in irradiated mice. Cell population expressing haptolgobin was resistant to y-ray.Conclusions: We for the first time have found that y-ray can induce haptoglobin expression in THP-1 cells. The mechanism of induction is different from other stimulus. Serum haptolglobin may be a useful biomarker for diagnosis of acute radiation injury.