Melatonin-Mediated Inhibitory Effect on Hyperimmune Status of Acquired Aplastic Anemia / 中国实验血液学杂志

OBJECTIVE@#To evaluate the expression level of melatonin and its effects on immune function in aplastic anemia (AA) patients.@*METHODS@#The enzyme-linked immunosorbent assay (ELISA) was used to detect the plasma levels of melatonin in AA patients, and the correlation between melatonin levels and laboratory indexs was analyzed. The activation, proliferation, and apoptosis of T cells from AA patients were analyzed by flow cytometry with or without melatonin in vitro.@*RESULTS@#The plasma levels of melatonin in AA patients were significantly lower compared with healthy controls (HC) (12.23 pg/ml vs 20.04 pg/ml, P < 0.01), while the plasma melatonin levels of AA patients in remission group after immunosuppressive therapy (IST) were significantly higher than those in non-remission group (29.16 pg/ml vs 11.73 pg/ml, P =0.04). Moreover, the melatonin levels were positively correlated with platelets (r =0.49), the absolute reticulocyte count (r =0.45), and the percentage of neutrophils (r =0.43). Meanwhile, there was a negative correlation between melatonin levels and the percentages of lymphocytes (r =-0.45). The expressions of CD25 and CD69 in both CD4+ and CD8+ T cells from AA patients were remarkably inhibited by melatonin in vitro (all P < 0.05). When cultured with melatonin, the proliferation rates of both CD4+ and CD8+ T cells from AA patients were markedly suppressed (P =0.01 andP < 0.01).@*CONCLUSION@#The plasma levels of melatonin were decreased in AA patients, which might play an important role in the mechanism of immunological abnormalities. The hyperimmune status of AA patients could be partially ameliorated by melatonin in vitro.

MiR-335-5p-Mediated Dysfunction of T Lymphocytes in Patients with Acquired Aplastic Anemia / 中国实验血液学杂志

OBJECTIVE@#To explore the effect of miR-335-5p/ADCY3 interaction on the lymphocyte function in the patients with aplastic anemia (AA).@*METHODS@#Blood samples were collected from 22 healthy volunteers (HC) and 50 AA patients including 38 severe AA (SAA) and 12 non-severe AA (NSAA). Peripheral blood mononuclear cells (PBMNC) were isolated. The expression of miR-335-5p and ADCY3 mRNA was detected by using RT-PCR. Negative control miR-335-5p (NC group) and miR-335-5p mimic (mimic group) were transfected to AA-PBMNC by using RNAimax reagent, respectively. The proliferative ability, activation and cytokines of CD4 T and CD8 T cells were measured by flow cytometry. Dual-luciferase reporter assay was used to verify the targeted relationship between miR-335-5p and target gene.@*RESULTS@#The expression of miR-335-5p was significantly downregulated in SAA-PBMNC and NSAA-PBMNC compared with HC-PBMNC (0.08±0.01 vs 0.74±0.10, P＜0.01; 0.17±0.02 vs 0.74±0.10, P＜0.01). Meanwhile, the expression of miR-335-5p in SAA-PBMNC was very statistically significantly lower than that in NSAA-PBMNC (P＜0.01). Compared with NC group, upregulation of miR-335-5p in vitro could significantly inhibited the proliferation of CD4 T and CD8 T cells in AA-PBMNC (P＜0.05 and P＜0.05, respectively). And, upregulating miR-335-5p in AA-PBMNC could significantly inhibited the activation of CD4 and CD8 T cells (P＜0.01 and P＜0.01, respectively). The ratio of CD4TNFα T, CD8IFNγ+T and CD8TNFα T cell by up-regulating the expression of miR-335-5p from AA-PBMNC in vitro was also significantly lower (P＜0.01, P＜0.05 and P＜0.05, respectively). In addition, the expression of ADCY3 was higher in AA-PBMNC than that in HC-PBMNC (1.70±0.15 vs 0.76±0.12, P＜0.01). Furthermore, by means of dual-luciferase reporter assay, the luciferase activity of ADCY3'UTR wildtype could be inhibited by miR-335-5p.@*CONCLUSIONS@#The expression of miR-335-5p was significantly downregulated in AA, and that correlates with disease severity. Up-regulating miR-335-5p can correct the hyperimmune status in AA patients by targeting ADCY3. These changes may relates with the strengthen of inhibition for targeted gene ADCY3.