Ribosome dysfunction underlies SLFN14-related thrombocytopenia.

Pathogenic missense variants in SLFN14, which encode an RNA endoribonuclease protein that regulates ribosomal RNA (rRNA) degradation, are known to cause inherited thrombocytopenia (TP) with impaired platelet aggregation and adenosine triphosphate secretion. Despite mild laboratory defects, the patients displayed an obvious bleeding phenotype. However, the function of SLFN14 in megakaryocyte (MK) and platelet biology remains unknown. This study aimed to model the disease in an immortalized MK cell line (imMKCL) and to characterize the platelet transcriptome in patients with the SLFN14 K219N variant. MK derived from heterozygous and homozygous SLFN14 K219N imMKCL and stem cells of blood from patients mainly presented with a defect in proplatelet formation and mitochondrial organization. SLFN14-defective platelets and mature MK showed signs of rRNA degradation; however, this was absent in undifferentiated imMKCL cells and granulocytes. Total platelet RNA was sequenced in 2 patients and 19 healthy controls. Differential gene expression analysis yielded 2999 and 2888 significantly (|log2 fold change| >1, false discovery rate <0.05) up- and downregulated genes, respectively. Remarkably, these downregulated genes were not enriched in any biological pathway, whereas upregulated genes were enriched in pathways involved in (mitochondrial) translation and transcription, with a significant upregulation of 134 ribosomal protein genes (RPGs). The upregulation of mitochondrial RPGs through increased mammalian target of rapamycin complex 1 (mTORC1) signaling in SLFN14 K219N MK seems to be a compensatory response to rRNA degradation. mTORC1 inhibition with rapamycin resulted in further enhanced rRNA degradation in SLFN14 K219N MK. Taken together, our study indicates dysregulation of mTORC1 coordinated ribosomal biogenesis is the disease mechanism for SLFN14-related TP.

Influence of ink and smoke ATM security systems on dactyloscopy and subsequent DNA analysis after detonation.

Automated Teller Machine bombings are an increasing societal problem that are often committed using Improvised Explosive Devices. The evolution in IEDs and the negative consequences for society require new security measures to prevent these crimes. Ink staining and security smoke devices are added to cash cassettes, in order to protect ATMs and prevent ATM bombings. Traces found at crime scenes, such as fingerprints and DNA, can contribute to the identification of perpetrators. However, the effect of ink staining and security smoke devices on dactyloscopy and DNA profiling is still unknown. In the current study, we demonstrate that procedures using Citrus Cleaner or sulfosalicylic acid were successful in removing ink and security smoke deposited on plastic plates but did result in the massive loss of fingerprint information as only a low number (4%) of good quality fingerprints were recovered after smoke contamination. Secondly, security ink Sun Blue ES2, but not SICPA Green and Sun Blue ES1, had a significant impact on DNA profiling success. DNA concentrations obtained from blood spiked swabs decreased with increasing ink concentration resulting in a complete loss of genotype information with the addition of ≥10 µl Sun Blue ES2. No noticeable PCR inhibition or DNA degradation was detected during quantification, but a decreased efficiency of DNA extraction could not be excluded. Security smoke, on the other hand, does not seem to have a significant influence on DNA analysis. Precautions must therefore be taken in order to avoid contaminating DNA swabs with ink during sampling. Thirdly, only a single negative impression of a glove in ink and a single glove print were able to be visualized with white fingerprint powder on detonated cash cassettes. In conclusion, the detection of glove prints and fingerprints is limited and security ink, contrary to smoke, after detonation can have a negative influence on downstream DNA analysis procedures.