👤 Özlem Ünal

Propylene glycol (PG) is incorporated into ruminant diets to boost glucogenic energy availability, yet its precise effects on adipose tissue development remain incompletely defined. The study was designed as a 3 × 3 factorial experiment with two independent variables: dose of PG and duration of fattening. Three groups were formed, including a dose group of PG 1.5 mL/kg live weight (PG1.5), a dose group of PG 3 mL/kg live weight (PG3), and a group without PG (PG0). Gluteal adipose tissues were collected from animals slaughtered on days 60, 90, and 120. mRNA, protein, and fatty acid profiles were analyzed. Protein-protein interaction and gene set enrichment analysis were also performed. On day 60, FABP4 was approximately 3-fold higher at both mRNA and protein levels in PG3 compared to PG0, nearly 2-fold higher at the protein level in PG1.5, and SREBP-1c protein levels were reduced in PG1.5 compared to PG0. On day 120, FABP4, PPARγ, C/EBPα exhibited an increasing trend at both mRNA and protein levels in PG groups, whereas SREBP-1c was decreased in PG3. Fatty acid profiling revealed C16:0, C18:0, and C18:1 comprised over 70% of total lipids. PG supplementation shifted the profile toward unsaturated species, reducing saturated fatty acid proportions and enhancing nutritional indices, particularly in PG1.5. Findings at the bioinformatics levels demonstrate PG exerts clear dose- and time-dependent modulation of adipogenic transcription factors, fatty acid composition, and molecular interaction networks in lamb adipose tissue. Early PG3 feeding elevates FABP4 and suppresses SREBP-1c, whereas prolonged supplementation enhances PPARγ and C/EBPα and drives a favorable shift in lipid profiles. Network and pathway analyses reveal coordinated regulation via NR1H3/RXR and PPAR axes, suggesting PG not only optimizes energy partitioning but also supports cellular homeostasis. These results could contribute to the development of potential strategies aimed at supporting adipose tissue quality and metabolic health in sheep. Show less

Carbamoyl phosphate synthetase 1 (CPS1) deficiency due to CPS1 mutations is a rare autosomal-recessive urea cycle disorder causing hyperammonemia that can lead to death or severe neurological impairment. CPS1 catalyzes carbamoyl phosphate formation from ammonia, bicarbonate and two molecules of ATP, and requires the allosteric activator N-acetyl-L-glutamate. Clinical mutations occur in the entire CPS1 coding region, but mainly in single families, with little recurrence. We characterized here the only currently known recurrent CPS1 mutation, p.Val1013del, found in eleven unrelated patients of Turkish descent using recombinant His-tagged wild type or mutant CPS1 expressed in baculovirus/insect cell system. The global CPS1 reaction and the ATPase and ATP synthesis partial reactions that reflect, respectively, the bicarbonate and the carbamate phosphorylation steps, were assayed. We found that CPS1 wild type and V1013del mutant showed comparable expression levels and purity but the mutant CPS1 exhibited no significant residual activities. In the CPS1 structural model, V1013 belongs to a highly hydrophobic β-strand at the middle of the central β-sheet of the A subdomain of the carbamate phosphorylation domain and is close to the predicted carbamate tunnel that links both phosphorylation sites. Haplotype studies suggested that p.Val1013del is a founder mutation. In conclusion, the mutation p.V1013del inactivates CPS1 but does not render the enzyme grossly unstable or insoluble. Recurrence of this particular mutation in Turkish patients is likely due to a founder effect, which is consistent with the frequent consanguinity observed in the affected population. Show less