Relationship between Injury Time and Expressions of EPO and Its Receptors in Rats Brain after Cerebral Injury / 法医学杂志

OBJECTIVE@#To explore the relationship between injury age and expressions of erythropoietin (EPO) and its receptor EPOR in the brain tissue of rats after cerebral injury.@*METHODS@#Seventy-two rats were randomly divided into control group (36 rats) and cerebral injury group (36 rats). The rats were sacrificed at 1, 2, 4, 8, 12, 24 h after cerebral injury (6 rats at each time point) and the brain tissues were extracted. The expressions of mRNA and protein of EPO and EPOR at different time points were detected by real-time fluorescent quantitative PCR and Western bloting.@*RESULTS@#The expressions of EPO and EPOR increased within 24 h after injury. The expressions of mRNA and protein of EPO were related to the injury age, and the correlations were 0.875, 0.911, respectively (P < 0.05). The expressions of mRNA and protein of EPOR were related to the injury age, and the correlation coefficients were 0.936, 0.905, respectively (P < 0.05).@*CONCLUSION@#The expressions of EPO and EPOR increase gradually in the early stage of the rat's cerebral injury, which are associated with the injury age and could be a useful value for estimating injury age.

Early Sustained Injections of Erythropoietin Improve Angiogenesis and Restoration of Perfusion in the Ischemic Mouse Hindlimb

This study was conducted to investigate the effects of erythropoietin (Epo) on both acute and chronic limb ischemia (ALI and CLI) and to evaluate the differences in mechanisms according to the method of Epo administration. Hindlimb ischemia was made in BALB/c mice with femoral artery ligation. The mice were divided into four groups: Group 1 (control, no treatment), Group 2 (ALI, early multiple doses), Group 3 (ALI, early single high dose), Group 4 (CLI, late multiple doses). Blood flow ratio significantly increased in Group 2 in 4 weeks. Expression of pAkt and Erythropoietin receptor were significantly higher in Group 2 on postoperative day (POD) 7. The number of CD31- and vascular endothelial growth factor-positive cells were significantly higher in Group 2 on POD 7 and 56. Group 3 and 4 showed a tendency of higher cell counts than the control. The early sustained Epo was effective in improving blood flow through angiogenesis. In chronic phase, weekly multiple dosing of Epo induced angiogenesis, however, the blood flow ratio did not increase significantly. The results of this study suggest that Epo administration during the acute phase followed by maintenance for several days may be important for increasing blood flow and angiogenesis.

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.

Myomatous erythrocytosis syndrome.

Uterine myomas are common but erythrocytosis caused by these is rarely seen. We report a case that illustrates the conjunction of various aetiological factors required for this clinical entity to evolve. A voluminous, retroperitoneally located and focally degenerated myoma was associated with severe secondary erythrocytosis (haematocrit: 65.5%) which resolved after hysterectomy. It has been demonstrated previously that myomatous tissue is the source of excessive production of erythropoietin. Local tissue hypoxia, which is more prone to develop in a pedunculated myoma, stimulates the process. Other prerequisites are a very large size of the myoma and the absence of menometrorrhagia of a severity such as to cause a depletion in iron reserves.