RHD-specific microRNA for regulation of the DEL blood group: integration of computational and experimental approaches.

OBJECTIVE: The discovery of specific microRNAs (miRNA) mediates a better understanding of molecular mechanisms, diagnosis and prognosis of complex phenotypes. Synthesis of the RhD blood group involves multiple factors causing variation in the expression of RHD antigens. The mechanism underlying the extremely weak expression of RHD antigen associated with the RHD variant called DEL (D-elute) is incompletely understood. Down-regulation of gene expression through miRNA is a guide to the potential involvement of miRNAs in the DEL blood group. In order to determine the association of miRNAs and Rh-DEL blood donors with DEL variant, we investigated the expression level RHD-specific miRNA. METHODS: Blood samples were serologically tested for RhD blood group determination. DNA was analysed using SSP-PCR for the Asian-type DEL allele (RHD 1227 G>A). Bioinformatics analyses were applied for prediction of candidate RHD-specific miRNA. The RHD-specific miRNA expression level was quantitated using a real-time-qPCR approach. The miRNA expression levels of various RhD blood groups were compared and statistically analysed. RESULTS: The bioinformatics tools (n = 3) for prediction of miRNA targeting on RHD identified miR-98 as the miRNA potentially specific for the 3' UTR of RHD. The relative expression levels of miR-98 among D-positive (n = 50), D-negative (n = 49) and DEL (n = 63) subjects showed no statistically significant differences (P-values = 0.58). CONCLUSION: This is the first attempt to determine whether miR-98 is involved in RHD expression using computational and experimental approaches. Further investigations are necessary to fully characterize the miRNA genetics in DEL blood group regulation.

Cationic and anionic fragmentation of dichloromethane following inner-shell (Cl 1s) photoexcitation.

The cationic and anionic fragmentation of dichloromethane (CH2Cl2) molecule have been investigated in the energy range of the Cl K shell by using synchrotron radiation, ion yield spectroscopy, and electron-ion coincidence spectroscopy. Total and partial ion-yield and mass spectra have been recorded as a function of the photon energy. We were able to identify several singly and multiply charged cationic fragments and the following anionic species: H-; C-; Cl-. The present results provide the first experimental report of negative ion formation from a molecule excited at the Cl 1s edge. In addition, our electron-ion coincidence data provide strong evidence of the preservation of molecular alignment for the photodissociation of CH2Cl2 after deep core-electron resonant excitation.