Research progress in erythropoietin mimetic peptides / 天津医药

Erythropoietin (EPO) is an active glycoprotein synthesized by kidney. The physiological function of regulat?ing the synthesis of erythrocytes by EPO makes it as a clinical drug for treatment of anemia resulted from chronic kidney fail?ure. However, its short biological half-life makes frequent administration, which limits its wide clinical utility since the tough burden and pain on patients. Therefore, the development of EPO derivatives with good efficacy, less adverse reaction and long duration has been a hot spot in the field during several decades. There are currently many different variants of EPO derivatives including erythropoiesis stimulating agents (ESAs) on the market. This article aims to summarize the recent re?search progress in the development of erythropoietin derivatives, specially focusing on EPO mimetic peptides (EMP).

Anti-EPO receptor antibodies in systemic lupus erythematosus with anemia / 中华风湿病学杂志

Objective To investigate the presentationand significance of circulating autoantibodies to erythropoietin receptor (EPOR) in sera from patients with systemic lupus erythematosus (SLE). Methods One hundred and twenty-four consecutive patients with SLE, seven with autoimmune hemolytic anemia (AIHA), 19 patients with iron deficiency anemia (IDA) and 45 normal individuals were involved in this study. In all patients with SLE, the disease activity was evaluated using the European consensus Lupus Activity Measurement scale. Antibodies to EPOR were detected by enzyme-linked immunosorbent assay (ELISA). All data were tested with Chi-squared or Student's t tests by SPSS software. Results A higher frequency of antibodies to EPOR were detected in SLE patients than healthy controls (20.2% vs 2.2%, P=0.004), however, they could not be detected in AIHA and IDA patients. Moreover, anti-EPOR antibodies were detected in 17 (33.3%) of 51 SLE patients with anemia, compared with that in 8 (11.0%, P=0.002) of 73 patients without anemia. Furthermore, patients with antibodies to EPOR had more severe anemia and often presented as microcytic anemia (P =0.005) than those without anti-EPOR antibodies. Finally, anti-EPOR antibodies seemed to be more likely to occur in patients with skin rash (P=0.014), low levels of C3 component of complement (P=0.01), positive anti-dsDNA antibodies (P=0.000) and higher disease activity scores (P= 0.024). Conclusion The higher incidence of antibodies to EPOR in SLE patients with anemia suggest that anti-EPOR antibodies might play a vital role in the development of anemia in SLE patients. Thus, detecting anti-EPOR antibodies in SLE patients with anemia may be helpful.

Progress of continuous erythropoietin receptor activator / 中国药理学与毒理学杂志

Erythropoietin(EPO) is a main growth factor that regulates the erythropoiesis under the physiological conditions and after blood loss. At present, it is one of the special effective clinical drugs for treating anemia due to renal failure, chronic infection, AIDS, tumor and some other causes. However, its short plasma half-life makes more frequent administration, which increases the burden and pain on patients. Therefore, development of long-acting agents is a hot. Continuous erythropoietin receptor activator(CERA) is a third-generation erythropoiesis-stimulating agents(ESA). It has a largely prolonged plasma half-life and extended administration intervals, which are different from other ESAs. This review gives a detail demonstration about the development, molecular structure, biochemical characteristics and the most common adverse effects of CERA, as well as the international attention when CERA works as a doping.

Capsaicin promotes the development of burst-forming nits-erythroid (BFU-E) from mouse bone marrow cells

Capsaicin, the pungent component of chilli peppers, is known to induce mediators of hematopoiesis. We investigated the effect of capsaicin on hematopoiesis in mouse progenitor cells. Treatment of mouse bone marrow cells with capsaicin induced the formation of colony of burst-forming units-erythroid (BFU-E). We also found that the number of erythropoietin receptor (EpoR)-positive cells was increased by capsaicin. To clarify the effect of capsaicin on erythroid lineage, BFU-E colonies were separated from non-BFU-E colonies by colony-picking after in vitro culture of mouse bone marrow cells. Quantitative RT-PCR analysis revealed that capsaicin stimulated the expression of the erythroid-specific genes encoding EpoR, glycophorin A (GPA), beta-globin (Hbb-b1), GATA-1, PU.1, nuclear factor erythroid-derived 2 (NF-E2), and Kruppel-like factor 1 (KLF1) in the BFU-E colonies. Furthermore, capsaicin could effectively stimulate the transfected GATA-1 promoter in K562 cells. GATA-1 is known as an essential transcription factor for the development of erythroid cells. Our results show that development of the erythroid lineage from bone marrow cells can be induced by treatment with capsaicin, and that GATA-1 seems to play a role in this induced erythroid maturation.

Progress in signal transduction of erythropoietin / 中国病理生理杂志

Erythropoietin is a critical growth factor in development of erythrocyte. After binding to its receptor, eryhropoietin produces biological action through consequent activation of intracellular signal transduction systems, including JAK2-STAT5, sos-Ras-MAPK, IRS-2- PI 3-K + and Ca 2+ channel.