Purpura fulminans related to paroxysmal nocturnal haemoglobinuria: a case report and literatures review / 中华血液学杂志

Objective: To improve the understanding of the rare clinical presentation and management of purpura fulminans (PF) in patients with paroxysmal nocturnal haemoglobinuria (PNH). Methods: A case of PF occurring in PNH is reported, while the related literature review is conducted. Results: A 49-year-old male patient suffered from one-week history of fever, greenish-brown colour urine, multiple well demarcated and painful purpura of the head and neck. He had been reported to have two thromboembolic events during the 22-year course of PNH. Skin biopsy displayed classic PF features. Laboratory testing showed a high PNH clone, intravascular hemolysis and coagulation system changes. After sufficient anticoagulation and short course of glucocorticoid therapy, the clinical conditions were improved correspondingly. During a follow-up period of 6 month, there was no recurrence of thrombosis. Conclusion: PF should be considered in PNH patients with unexplained, quickly developed painful purpura. Extensive work-up should be performed to find out other potential thrombophilic risk factors after diagnosis of PF. Early diagnosis, adequate anticoagulation therapy and control hemolysis were essential to PF treatment occurring in PNH. The survival of patients and the qualities of life can be improved. The PNH clone detection is needed to evaluate the status of procoagulation and predict the risk of recurrent thrombosis.

Effect of sirolimus on erythropoiesis of K562 cell line and patients with pure red cell aplasia in vitro / 中华血液学杂志

Objective: To understand the effect of sirolimus on the erythropoiesis of K562 cell line and bone marrow cells from pure red cell aplasia (PRCA) patients and normal controls. Methods: Different concentrations (10, 100, 1 000 nmol/L) of sirolimus were added to the K562 cell line or bone marrow cells from PRCA patients or normal controls and cultured 14 days for BFU-E formation. Meanwhile, sirolimus was also added to the serum treated PRCA bone marrow cells to cultivate for the same priod of time. Results: Neither K562 cells, bone marrow cells from PRCA patients or normal controls showed any difference when sirolimus was added to the culture system for BFU-E. However, BFU-E formation decreased after serum was added in PRCA patients (76.40±22.48 vs 136.33±12.58, t=-4.329, P=0.001) and this suppression of BFU-E was partly corrected by 1 000 nmol/L sirolimus treatment (97.14±15.83 vs 76.40±22.48, P=0.038). Conclusions: Sirolimus may modulate the suppression of erythropoiesis by serum instead of directly stimulate the growth of red blood cells in PRCA patients.

Myr-RKEFAK Peptide Selectively Regulates Outside-in Signaling Transduction-related Functions in Human Platelets / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To study the effect of interaction of the talin rod domain integrin binding site 2 with integrin β3 on platelet signal transduction.</p><p><b>METHODS</b>A peptide that mimics the membrane proximal α helix 6 residues R724 KEFAK729 of the integrin β3 cytoplasmic tails was designed and synthesized, to which the myristoylation was covalently linked to the N-terminal of the peptide enabling membrane penetration. The effects of myr-RKEFAK peptide on the typical platelet outside-in signaling ovent (stable adhesion and spreading on immobilized fibrinogen, aggregation, fibrin clot retraction) and inside-out signaling events (soluble fibrinogen binding) were tested.</p><p><b>RESULTS</b>myr-RKEFAK peptide dose-dependently inhibited platelet stable adhesion and spreading on immobilized fibrinogen, irreversible aggregation, as well as fibrin clot retraction, but not soluble fibrinogen binding and reversible phase of platelet aggregation.</p><p><b>CONCLUSION</b>The cell-penetrating peptide myr-RKEFAK causes an inhibitory effect on integrin β3 outside-in signaling-regulated platelets functions, but did not affect inside-out signaling-regulated platelets functions.</p>

Effect of the Integrin β3 Cytoplasmic NITY Motif on α II bβ3-Mediated Cell Functions in CHO Cell Model / 中国实验血液学杂志

<p><b>UNLABELLED</b>OBJLECTIVE: To investigate the effect of integrin β3 cytoplasmic NITY motif on αIIbβ3-mediated cell functions.</p><p><b>METHODS</b>Stable Chinese hamster ovary (CHO) cell lines that co-express human wild type integrin αIIb and wild type β3 or mutant β3ΔNITY (β3 deleting cytoplasmic NITY motif) were established. Expression of αIIb and β3 were tested by Western blot and flow cytometry in CHO cell lines. Spreading and adhesion of stable cell lines on immobilized fibrinogen were examined. The co-immunoprecipitation was used to detect protein interactions.</p><p><b>RESULTS</b>CHO-αIIbβ3, CHO-αIIbβ3ΔNITY cells were successfully established. The CHO cells transfected with wild type αIIbβ3 had the ability of adhesion and spreading. Compared with CHO-αIIbβ3 cells, CHO-αIIbβ3ΔNITY cells showed an impaired capacity of adhesion but no significant difference was observed in spreading of adhered cells. The co-immunoprecipitation showed that kindlin-2 associated with wild type integrin αIIbβ3. The β3ΔNITY mutation substantially reduced kindlin-2 association.</p><p><b>CONCLUSION</b>Deletion of NITY motif causes an impaired ability of adhesion. The deletion mutation can suppress kindlin-2 binding to integrin β3, thereby partially inhibit the integrin β3 signaling.</p>