Effect of glutaryl-CoA dehydrogenase gene silencing and high-concentration lysine on the viability of BRL hepatocytes / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the effect of glutaryl-CoA dehydrogenase (GCDH) gene silencing and accumulation of lysine metabolites on the viability of hepatocytes.</p><p><b>METHODS</b>BRL cells were divided into normal control group, negative control group, and GCDH silencing group. The shRNA lentiviral vector for silencing GCDH gene was constructed, and the BRL hepatocytes in the GCDH silencing group and the negative control group were infected with this lentivirus and negative control virus respectively, and then cultured in a medium containing 5 mmol/L lysine. Immunofluorescence assay was used to measure the infection efficiency of lentivirus. Western blot was used to measure the expression of GCDH protein. MTT assay was used to evaluate cell viability. Hoechest33342 staining was used to measure cell apoptosis. Western blot was used to measure the expression of Caspase-3, an index of cell apoptosis.</p><p><b>RESULTS</b>The lentivirus constructed effectively silenced the GCDH gene in hepatocytes (P<0.01). MTT assay and Hoechest 33342 staining showed no significant differences in cell viability and apoptosis between groups (P>0.05). There was also no significant difference in the expression of Caspase-3 protein between groups (P>0.05).</p><p><b>CONCLUSIONS</b>GCDH gene silencing and accumulation of lysine metabolites may not cause marked hepatocyte injury.</p>

Effects of intrauterine growth retardation with catch-up growth on sugar-lipid metabolism and adipocyte function in young rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study changes of glycolipid metabolism and adipocyte function in an catch-up growth intrauterine growth retardation (IUGR) rat model.</p><p><b>METHODS</b>IUGR rat model was established by maternal nutrition restriction during pregnancy. Newborn IUGR pups were used as IUGR group, and normal newborn pups were used as control group (appropriate for gestational age, AGA group). At age of 12 weeks, plasma samples were collected for the test of triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), adiponectin and acylation stimulating protein (ASP). Oral glucose tolerance test (OGTT) was performed for the test of glucose and insulin levels, and insulin resistance index (IRI) was calculated. Expression of glucose transfer 4 (GLUT-4) in adipocytes was examined by confocal microscopy.</p><p><b>RESULTS</b>Body weight and BMI in the IUGR group were significantly higher than in the AGA group by 12 weeks (P<0.01), and plasma TC, TG and LDL-C levels in the IUGR group were higher than in the AGA group, but HDL-C was lower (P<0.05). In the OGTT test, blood glucose level and IRI score in the IUGR group were higher than in the AGA group (P<0.05). Compared with the AGA group, the IUGR group had a higher ASP level (P<0.05) and a lower adiponection level (P<0.05). GLUT4 expression in the adipocytes was significantly lower in the IUGR group than in the AGA group (P<0.05).</p><p><b>CONCLUSIONS</b>Catch-up growth may be obviously noted in IUGR rats after birth. Both hyperlipidaemia and insulin resistance occur at age of 12 weeks. Dysfunction of adipocytes decreased expression of GLUT-4 may be risk factors for insulin resistance in IUGR rats.</p>

Effects of PI3K inhibitor LY294002 on the differentiation of mouse preadipocytes and the expression of C/EBPα and PPARγ / 中国当代儿科杂志

<p><b>OBJECTIVE</b>This study examined the effects of PI3K inhibitor LY294002 on the differentiation of mouse preadipocytes and the expression of CCAAT enhancer binding protein α (C/EBPα) and peroxisome proliferation activated receptor γ (PPARγ), in order to study the possible roles of insulin receptor substrate (IRSs)/PI3K signal pathway in the differentiation of preadipocytes.</p><p><b>METHODS</b>The mouse 3T3-L1 cells were cultured normally and divided into experimental and control groups. 3T3-L1 cells in the experimental group were treated with PI3K inhibitor LY294002 (25 μmol/L) and those in the control group were treated with DMSO culture medium. 3-isobutyl-1-methylxanthine (IBMX) (0.5 mmol/L), dexamethasone (10-6 mol/L) and insulin (5 μg/mL) were used to induce the differentiation of 3T3-L1 preadipocytes in both groups. Before culture, and 2, 4 and 8 days after culture, the cells were collected to detect the expression of C/EBPα and PPARγ by real-time PCR and Western blot assays. The lipid droplets of 3T3-L1 preadipocytes were observed by oil-red O staining.</p><p><b>RESULTS</b>PI3K inhibitor LY294002 did not affect the expression of C/EBPα and PPARγ in un-induced 3T3-L1 preadipocytes (P>0.05), but decreased the expression of C/EBPα and PPARγ during the in vitro induced differentiation of 3T3-L1 preadipocytes compared with the control group (P<0.05 or 0.01). The lipid droplets count was greatly reduced by LY294002.</p><p><b>CONCLUSIONS</b>PI3K inhibitor LY294002 can inhibit the differentiation of mouse 3T3-LI preadipocytes and the expression of C/EBPα and PPARγ in the differentiation of 3T3-LI preadipoeytes, suggesting that IRSs/PI3K signal pathway may play an important role in the differentiation of 3T3-L1 preadipocytes by regulating the expression of C/EBPα and PPARγ.</p>

Clinical features and growth hormone receptor gene mutations of patients with Laron syndrome from a Chinese family / 中国当代儿科杂志

Laron syndrome is an autosomal recessive disorder caused by defects of growth hormone receptor (GHR) gene. It is characterized by severe postnatal growth retardation and characteristic facial features as well as high circulating levels of growth hormone (GH) and low levels of insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3). This report described the clinical features and GHR gene mutations in 2 siblings with Laron syndrome in a Chinese family. Their heights and weights were in the normal range at birth, but the growth was retarded after birth. When they presented to the clinic, the heights of the boy (8 years old) and his sister (11 years old) were 80.0 cm (-8.2 SDS) and 96.6 cm (-6.8 SDS) respectively. They had typical appearance features of Laron syndrome such as short stature and obesity, with protruding forehead, saddle nose, large eyes, sparse and thin silky hair and high-pitched voice. They had higher basal serum GH levels and lower serum levels of IGF-I, IGFBP-3 and growth hormone binding protein (GHBP) than normal controls. The peak serum GH level after colonidine and insulin stimulations in the boy was over 350 ng/mL. After one-year rhGH treatment, the boy's height increased from 80.0 cm to 83.3 cm. The gene mutation analysis revealed that two patients had same homozygous mutation of S65H (TCA -->CCA) in exon 4, which is a novel gene mutation. It was concluded that a definite diagnosis of Laron syndrome can be made based on characteristic appearance features and serum levels of GH, IGF-I, IGFBP-3 and GHBP. The S65H mutation might be the cause of Laron syndrome in the two patients.

Analysis of ABCD1 Gene Mutation in Patients with X-Linked Adrenoleukodystrophy / 实用儿科临床杂志

Objective To analyze the ABCD1 gene mutations in 5 cases of X-linked adrenoleukodystrophy(X-ALD) patients and 2 cases of their mothers.Methods Of 5 patients with X-ALD,10 exons and flanking intronic sequences of ABCD1 gene were amplified by polyme-rase chain reaction,and then sequenced directly.The outcomes were compared with normal ABCD1 sequencings to identify the mutation type and site.Thirty normal men were examined in the mean time as control for the confirmation of mutations and gene polymorphisms.Results Three patients showed ABCD1 gene mutations,1 had a point mutation in exon 6,Arg518Gly(CGG→GGG);2 patients showed the same novel mutation in exon 1 with 8 bases deletion(134del8).Four gene polymorphisms were identified in exon 7.They were Gly551X(GGC→GGT),Arg554His(CGT→CAT),Gln567Arg(CAA→CGA) and Val582Ile(GTC→ATC).ABCD1 gene mutation was not found in 2 mothers from 2 unrelated fa-milies with X-ALD.Conclusions Three cases of 5 were detected for ABCD1 gene mutations.Between them,the 134del8 mutation is a novel one.Four new gene polymorphisms were detected in exon 7 in normal Chinese people,which were Gly551X,Arg554His,Gln567Arg and Val582Ile.

Insulin receptor substrate expression and insulin resistance in intrauterine growth retarded rats / 中华内分泌代谢杂志

Insulin receptor substrate(IRS)-1 and IRS-2 expression levels of liver tissues and skeletal muscle in intrauterine growth retarded(IUGR)rats were investigated by RT-PCR and immunohistochemistry.An IUGR animal model was established by maternal nutrition restriction during pregnancy.IRS-2 expression level of liver tissue and IRS-1 expression level of skeletal muscle in IUGR rats at 0 and 3 weeks old were significantly lower than those in normal rats at the same age respectively,and insulin resistance was induced in IUGR,and these findings might be the molecular mechanisms susceptible to metabolic syndrome in IUGR rats.