A novel stop-gain mutation in DPYS gene causing Dihidropyrimidinase deficiency, a case report.

BACKGROUND: Dihidropyrimidinase (DHP) deficiency is an inherited inborn error of pyrimidine metabolism with a variable clinical presentation and even asymptomatic subjects. Dihydropyrimidinase is encoded by the DPYS gene, thus pathogenic mutations in this gene can cause DHP deficiency. To date, several variations in the DPYS gene have been reported but only 23 of them have been confirmed to be pathogenic. Therefore, the biochemical, clinical and genetic aspects of this disease are still unclear. CASE PRESENTATION: Here, we report a 22-year-old woman with DHP deficiency. To identify the genetic cause of DHP deficiency in this patient, Whole Exome Sequencing (WES) was performed, which revealed a novel homozygote stop gain mutation (NM_001385: Exon 9, c.1501 A > T, p.K501X) in the DPYS gene. Sanger sequencing was carried out on proband and other family members in order to confirm the identified mutation. According to the homozygote genotype of the patient and heterozygote genotype of her parents, the autosomal recessive pattern of inheritance was confirmed. In addition, bioinformatics analysis of the identified variant using Mutation Taster and T-Coffee Multiple Sequence Alignment showed the pathogenicity of mutation. Moreover, mRNA expression level of DPYS gene in the proband's liver biopsy showed about 6-fold reduction compared to control, which strongly suggested the pathogenicity of the identified mutation. CONCLUSIONS: This study identified a novel pathogenic stop gain mutation in DPYS gene in a DHP deficient patient. Our findings can improve the knowledge about the genetic basis of the disease and also provide information for accurate genetic counseling for the families at risk of these types of disorders.

Clinical and molecular characterization of three patients with Hepatocerebral form of mitochondrial DNA depletion syndrome: a case series.

BACKGROUND: Mitochondrial DNA depletion syndromes (MDS) are clinically and phenotypically heterogeneous disorders resulting from nuclear gene mutations. The affected individuals represent a notable reduction in mitochondrial DNA (mtDNA) content, which leads to malfunction of the components of the respiratory chain. MDS is classified according to the type of affected tissue; the most common type is hepatocerebral form, which is attributed to mutations in nuclear genes such as DGUOK and MPV17. These two genes encode mitochondrial proteins and play major roles in mtDNA synthesis. CASE PRESENTATION: In this investigation patients in three families affected by hepatocerebral form of MDS who were initially diagnosed with tyrosinemia underwent full clinical evaluation. Furthermore, the causative mutations were identified using next generation sequencing and were subsequently validated using sanger sequencing. The effect of the mutations on the gene expression was also studied using real-time PCR. A pathogenic heterozygous frameshift deletion mutation in DGUOK gene was identified in parents of two affected patients (c.706-707 + 2 del: p.k236 fs) presenting with jaundice, impaired fetal growth, low-birth weight, and failure to thrive who died at the age of 3 and 6 months in family I. Moreover, a novel splice site mutation in MPV17 gene (c.461 + 1G > C) was identified in a patient with jaundice, muscle weakness, and failure to thrive who died due to hepatic failure at the age of 4 months. A 5-month-old infant presenting with jaundice, dark urine, poor sucking, and feeding problems was also identified to have another novel mutation in MPV17 gene leading to stop gain mutation (c.277C > T: p.(Gln93*)). CONCLUSIONS: These patients had overlapping clinical features with tyrosinemia. MDS should be considered a differential diagnosis in patients presenting with signs and symptoms of tyrosinemia.

Comparison of Autar scale and Wells criteria in DVT risk assessment by nurses in patients with lower extremity trauma.

BACKGROUND: Deep vein thrombosis (DVT) is a common and preventable complication in patients with lower extremity trauma. DVT prediction is considered to be necessary. PURPOSE: This study aimed to compare the Autar DVT risk assessment scale with modified Wells criteria in predicting DVT by nurses in patients with lower extremity trauma. METHODS: Patients with lower extremity trauma patients who met the requirements for this study were assessed by both the Autar and Wells tools for DVT risk assessment during the first 24 hours after their admission. Statistical analysis was performed using SPSS 18. RESULTS: There was a significant and direct statistical relationship between the results of risk assessment of these two tools based on Pearson correlation (r= 0.731, P<0.0001). Kappa coefficient between the two was 53%. Sensitivity and specificity of the Autar scale were 100% and 68%, respectively, which revealed a higher degree of sensitivity than that of the Wells criteria. CONCLUSION: Although the results of DVT prediction for the Autar scale and modified Wells criteria were consistent, the Autar DVT risk assessment scale showed higher sensitivity. Therefore, it is recommended that the Autar scale be used to achieve more precise DVT predictions.

AICAR and nicotinamide treatment synergistically augment the proliferation and attenuate senescence-associated changes in mesenchymal stromal cells.

BACKGROUND: Mesenchymal stromal cell (MSC) stemness capacity diminishes over prolonged in vitro culture, which negatively affects their application in regenerative medicine. To slow down the senescence of MSCs, here, we have evaluated the in vitro effects of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), an AMPK activator, and nicotinamide (NAM), an activator of sirtuin1 (SIRT1). METHODS: Human adipose-derived MSCs were cultured to passage (P) 5. Subsequently, the cells were grown in either normal medium alone (control group), the medium supplemented with AICAR (1 mM) and NAM (5 mM), or in the presence of both for 5 weeks to P10. Cell proliferation, differentiation capacity, level of apoptosis and autophagy, morphological changes, total cellular reactive oxygen species (ROS), and activity of mTORC1 and AMPK were compared among different treatment groups. RESULTS: MSCs treated with AICAR, NAM, or both displayed an increase in proliferation and osteogenic differentiation, which was augmented in the group receiving both. Treatment with AICAR or NAM led to decreased expression of ß-galactosidase, reduced accumulation of dysfunctional lysosomes, and characteristic morphologic features of young MSCs. Furthermore, while NAM administration could significantly reduce the total cellular ROS in aged MSCs, AICAR treatment did not. Moreover, AICAR-treated cells possess a high proliferation capacity; however, they also show the highest level of cellular apoptosis. The observed effects of AICAR and NAM were in light of the attenuated mTORC1 activity and increased AMPK activity and autophagy. CONCLUSIONS: Selective inhibition of mTORC1 by AICAR and NAM boosts autophagy, retains MSCs' self-renewal and multi-lineage differentiation capacity, and postpones senescence-associated changes after prolonged in vitro culture. Additionally, co-administration of AICAR and NAM shows an additive or probably a synergistic effect on cellular senescence.

The toxicity and therapeutic effects of single-and multi-wall carbon nanotubes on mice breast cancer.

Herein, we have investigated the toxicity of SWCNTs and MWCNTs in vitro and in vivo, and assessed their therapeutic effects on a typical animal model of breast cancer in order to obtain: first, the cytotoxicity effects of CNTs on MC4L2 cell and mice, second the impact of CNTs on ablation of breast tumor. CNTs especially SWCNTs were toxic to organs and induced death at high dosages. In this case, some of the liver cells showed a relative shrinkage which was also confirmed by Annexin test in MC4L2 cells. Moreover, CNTs decreased the tumor volume. BCL2 gene was down-regulated, and BAX and Caspase-3 were also up-regulated in the treated groups with CNTs. As a result, CNTs especially MWCNT in lower dosages can be used as a promising drug delivery vehicle for targeted therapy of abnormal cells in breast cancer.