Protective effect of cotransfection of A20 and HO-1 gene against the apoptosis induced by TNF-α in rat islets in vitro / 中华儿科杂志

<p><b>OBJECTIVE</b>To establish the method for cotransferring human A20 gene and human heme oxygenase-1 (HO-1) gene into the isolated rat islets using lentiviral transfection system, and to study the protective effect of A20 and HO-1 protein against the apoptosis induced by cycloheximide (CHX) and TNF-α, and finally to explore the underlying mechanism.</p><p><b>METHOD</b>The A20 gene and HO-1 gene were cloned and inserted into the lentiviral transfection system. The efficacy of gene transfer was measured by the intensity of the enhanced green fluorescent protein (EGFP) fluorescence-positive islets. Western blot was applied to verify the expression of the A20 and HO-1 genes. To induce apoptosis in vitro, the isolated islets were treated with CHX+TNF-α, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and the fluorescence-activated cell sorting (FACS) methods were used to evaluate the apoptosis of the islet cells and Western blot was used to detect caspase-3 activation.</p><p><b>RESULT</b>(1) A20 and HO-1 genes were introduced into the isolated islets by lentiviral transfection, both of the genes were highly expressed in the islets after 96 hours culture detected by Western blot method. (2) The insulin levels in the cell culture medium from A20 and/or HO-1 transgenic islets were significantly higher than that in non-transgenic controls (P < 0.01). (3)After CHX + TNF-alpha treatment, the cell culture medium insulin concentration in the A20 gene transfected group [(93.58 ± 4.12)µg/ml], HO-1 gene transfected group [(88.98 ± 4.77) µg/ml ] and A20/HO-1 co-transfected group [(103.33 ± 3.16) µg/ml] were significantly higher than that in the EGFP group [(9.03 ± 0.65) µg/ml ] and the control group [(8.86 ± 0.38) µg/ml] (P < 0.001). Minimum expression level of the activated caspase-3 was found in the A20/HO-1 co-transfected group.</p><p><b>CONCLUSION</b>The lentiviral gene transfer system was an efficient and stable gene transfer vector, the over-expressed A20 and HO-1 protein delivered via lentivirus could preserve rats' islets function and act against the apoptosis induced by CHX and TNF-α.</p>

The establishment of "two-step sequential filtration method" on the yield rate of purified islets in rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To develop a simple, rapid and reliable method of purifying Sprague-Dawley (SD) rat islets by sequential filtration through two cell strainers of different sizes and to evaluate the efficacy of the method.</p><p><b>METHODS</b>Islets were isolated from 8 to 12-week-old clean grade Sprague-Dawley rat pancreases using the standard collagenase digestion procedure and purified with either the generally used Ficoll density gradient method or the innovative two-step sequential filtration method. The purity and vitality of the isolated islets were visualized and assessed with DTZ and AO/PI staining. Glucose stimulating tests were performed to assay cell activity, and immunohistochemical staining was used to evaluate the synthesis function of islet cells.</p><p><b>RESULTS</b>The yield of islets in the two-step filtration method group was 782±115 IEQ per rat, which was significantly higher than in the conventional Ficoll density gradient method group (598 ± 135 IEQ per rat, P < 0.01). Purity of the isolated islets in the two-step filtration method group was 90%-100% and vitality was over 95%. In the conventional Ficoll density gradient method group, islet purity was 65%-85% and vitality was 85%-95%. With regard to the high-sugar stimulation test in the two-step filtration method group, insulin concentrations in islets cultured for 24 hours were significantly higher than in those that were freshly purified (76.9 ± 6.1 μg/L vs 49.4 ± 3.9 μg/L; P < 0.01).</p><p><b>CONCLUSIONS</b>A two-step sequential filtration method for rat islet purification was developed and the method was simple and reliable, with high islet vitality, purity and yield.</p>

Lipoprotein lipase gene mutations and the risk of cardiovascular diseases in children with obesity / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To inquire into the relationship between lipoprotein lipase (LPL) gene D9N, N291S and S447X polymorphisms and the development of cardiovascular diseases in children with obesity.</p><p><b>METHODS</b>The polymerase chain reaction (PCR) and restriction fragment length polymorphism (RLFP) techniques were used to detect three common mutations of LPL gene exon D9N, N291S and S447X in 157 obese children and 175 normal controls. Plasma lipid and lipoprotein levels between children with different genotypes were compared.</p><p><b>RESULTS</b>The D9N and N291S gene mutations were not detected in either the obese or the control groups. There were no significant differences in the frequency of S447X gene mutation between the two groups. There were no significant differences in the levels of plasma lipid and lipoprotein between children with S447 and X447 genotypes.</p><p><b>CONCLUSIONS</b>D9N and N291S gene mutations may not be risk factors associated with cardiovascular diseases in children with obesity. S447X gene mutation might not play an important role in the development of cardiovascular diseases in childhood.</p>

Efficacy and safety of recombinant human growth hormone solution in children with growth hormone deficiency in China: a multicenter trial / 中华儿科杂志

<p><b>OBJECTIVE</b>Human growth hormone (hGH) is an essential therapeutic drug for the treatment of growth hormone (GH) deficiency (GHD). However, the process of dissolving hGH of the powder form is complicated and potentially hazardous. In the present study, we evaluated the efficacy and safety of preparation in the replacement therapy for children with GH deficiency.</p><p><b>METHODS</b>A 12-month randomized, open-label, multicenter trial was conducted in 31 previously untreated children with growth failure secondary to GH deficiency [20 boys and 11 girls, mean age (10.5 +/- 4.1) years]. An recombined human growth hormone (rhGH) solution (Iintropin AQ) was given via subcutaneous injection daily in every evening at a weekly dose of 0.25 mg/kg. The patients were followed up at 3, 6, 9, and 12 months of the treatment, and the course of treatment was 12 months. Body height was measured 3-monthly and height velocity (HV) and mean height standard deviation score (HT SDS) were calculated. Serum Insulin-like growth factor I (IGF-1), Insulin-like growth factor binding protein 3 (IGFBP-3), GH antibodies and safety parameters were assessed at the baseline and at 3-month intervals. Bone age (BA) was assessed at the baseline and the rate of skeletal maturation (DeltaBA/DeltaCA) was calculated after 6 and 12 months of rhGH treatment by a central bone age reader. Moreover, the safety of rhGH solution treatment was assessed.</p><p><b>RESULTS</b>After 12 months of liquid rhGH therapy, growth parameters were significantly increased over baseline. (1) The mean (+/- SD) height increment DeltaHT (cm) was 4.0 +/- 1.3, 7.0 +/- 2.0, 10.3 +/- 2.6 and 12.9 +/- 3.3 after 3, 6, 9, and 12 months of treatment, respectively (P < 0.01), which indicated linear growth after treatment. The GV (cm/years) was 2.7 +/- 0.9 before treatment and increased to 16.0 +/- 5.1, 14.1 +/- 4.0, 13.7 +/- 3.5, and 12.9 +/- 3.3 after treatment, suggesting that catch-up growth was significant after treatment as compared to the pre-treatment status (P < 0.01). Accordingly, post-treatment catch-up growth was obvious, significant differences were observed in HT SDS, which was -4.62 +/- 1.46 at the onset of therapy and increased significantly after the treatment to -3.80 +/- 1.53, -3.28 +/- 1.60, -2.86 +/- 1.75 and -2.47 +/- 1.86, respectively (P < 0.01). The height difference between GH deficient children and unimpaired children of the same age and gender gradually decreased after treatment, which was significantly different from that seen before treatment (P < 0.01). (2) The levels of serum IGF-1 and IGFBP-3 were increased comparably for the treatment. IGF-1 level (microg/L) was 41 +/- 64 at baseline and increased to 179 +/- 155, 202 +/- 141, 156 +/- 155 and 159 +/- 167 after 3, 6, 9, 12 months of treatment. IGFBP-3 level (mg/L) was 1540 +/- 1325 at baseline, and increased to 3891 +/- 1815, 4051 +/- 1308, 3408 +/- 1435 and 3533 +/- 1413, respectively, suggesting that with the increases in height, IGF-1, and IGFBP-3 were significantly activated to relatively high levels by the medication and reached peak values between 3 and 6 months of treatment. The levels of IGF-1 and IGFBP-3 were significantly different before and after treatment (P < 0.01). The IGF-1/IGFBP-3 molar ratio significantly increased during GH therapy (0.143 +/- 0.013 pre-therapy up to 0.240 +/- 0.055 post-therapy, P < 0.01). The IGF-1/IGFBP-3 molar ratio tended to stabilize after 3-month GH therapy. (3) The bone age assessment carried out 6 and 12 months after treatment showed that the bone maturity (DeltaBA/DeltaCA) was 1.01 +/- 0.57 and 1.07 +/- 0.75, respectively, suggesting that there was no speed-up development in the bone age. No severe adverse events were observed during the trial and the most frequent accompanying event was mild hypothyroidism.</p><p><b>CONCLUSIONS</b>rhGH solution (Iintropin AQ) is a safe and effective preparation in the replacement therapy for children with GH deficiency.</p>