DHA (22:6n-3) is a Ω-3 polyunsaturated fatty acid with 22 carbon atoms and 6 double bonds, which has important biological functions in human body. Human and other mammals synthesize only limited amounts of DHA, more requirements must be satisfied from food resources. However, the natural resources of DHA (Mainly deep-sea fish and other marine products) are prone to depletion. New resources development is still insufficient to satisfy the growing market demand. Previous studies have revealed that the mammals can increase the synthesis of DHA and other long-chain polyunsaturated fatty acids after transgenic procedures. In this study, mammalian cells were transfected with Δ6, Δ5 desaturase, Δ6, Δ5 elongase, Δ15 desaturase (Isolated from nematode Caenorhabditis elegans) and Δ4 desaturase (Isolated from Euglena gracilis), simultaneously. Results show that the expression or overexpression of these 6 enzymes is capable of conversion of the o-6 linoleic acid (LA, 18:2n-6) in DHA (22:6n-3). DHA content has increased from 16.74% in the control group to 25.3% in the experimental group. The strategy and related technology in our research provided important data for future production the valuable DHA (22:6n-3) by using genetically modified animals.
Animals ; Caenorhabditis elegans ; enzymology ; Cells, Cultured ; Docosahexaenoic Acids ; chemistry ; Euglena gracilis ; enzymology ; Fatty Acid Desaturases ; biosynthesis ; Linoleic Acid ; chemistry ; Mammals ; Transfection

Objective To explore the correlation between exponential apparent diffusion coefficient(eADC)value before radical hysterectomy and postoperative clinical results in patients with International Federation of Gynecology and Obstetrics(FIGO)stageⅠ/Ⅱ cervical cancer,and to find MR quantitative indicators for predicting the prognosis of patients with early stage cervical cancer.Methods Patients with FIGO stage Ⅰ/Ⅱ cervical cancer who underwent surgical treatment were retrospectively collected.All patients underwent MRI plain scan and diffusion weighted imaging(DWI)scan before surgery.Baseline parameters included age,menopause,stage,tumor size,pathological differentiation and type,lymph node involvement,and postoperative adjuvant therapy.MR parameters included mean apparent diffusion coefficient(ADCmean),normalized apparent diffusion coefficient(nADC),eADC,SIDWI,and SIT2.Baseline and MRI parameters associated with recurrence were determined by Cox regression analysis.Results The progression-free survival(PFS)in the low eADC group was longer than that in the high eADC group(P=0.010).Univariate analysis showed that ADC,nADC and eADC were associated with recurrence(P<0.05).In multivariate analysis,only eADC[hazard ratio(HR)3.610;95%confidence interval(CI)1.467-8.886;P=0.005]was associated with recurrence.Conclusion Preoperative eADC is associated with PFS in patients with surgically treated FIGO stage Ⅰ/Ⅱ cervical cancer and is helpful in evaluating the prognosis of patients with cervical cancer.