OBJECTIVE: To determine whether the infertile patients with polycystic ovarian syndrome (PCOS) is related to dysregulation of peritoneal fluid and serum leptin concentration, and to investigate the relationship between the leptin and some endocrine hormones in PCOS. METHODS: Twenty subjects with PCOS and 20 control women were included in the study. Peritoneal fluid and serum concentration of leptin, insulin, insulin-antibody, testosterone (T), estrogen (E(2)), and progestogen (P) were measured by radioimmunoassay (RIA). RESULTS: Peritoneal fluid concentrations of leptin, insulin, T and insulin-antibody in PCOS patients were significantly higher than those of the control group (P<0.05). There was no statistically significant difference in peritoneal fluid E(2) and P between PCOS and the control group (P>0.05). The serum concentrations of leptin and T in PCOS were significantly higher than those of the control group (P<0.05), but the levels of insulin, E(2), P and insulin-antibody were not significantly different between the 2 groups (P>0.05). With the BMI> or =23 kg/m(2) subgroup in PCOS patients, the peritoneal fluid and serum concentrations of leptin, insulin and T were significantly higher than those of BMI 23 kg/m(2) subgroup (P<0.01). There was no significant difference in E(2)and insulin-antibody between the 2 subgroups (P>0.05). Pearson correlation analysis indicated that peritoneal fluid and serum leptin levels were positively correlated with BMI, insulin, T and insulin-antibody, but negatively correlated with E(2), with no significant correlation with P. Multiple stepwise regression analysis indicated that the factors that influenced the peritoneal fluid and serum leptin levels were BMI, insulin, T and E(2) ordinally. CONCLUSION Peritoneal fluid and serum leptin concentration and insulin,T, Ins-antibody level are abnormal in PCOS patients. Leptin may play an important role in the pathogenesis of PCOS. BMI is the main factor to correlate with leptin.
Adult ; Ascitic Fluid ; metabolism ; Autoantibodies ; biosynthesis ; Estrogens ; biosynthesis ; Female ; Humans ; Insulin ; biosynthesis ; immunology ; Leptin ; biosynthesis ; Polycystic Ovary Syndrome ; metabolism ; Progesterone ; biosynthesis ; Testosterone ; biosynthesis

OBJECTIVETo observe the expression of insulin in the brain tissue of rat after scald.

METHODSFifteen Wistar rats subjected to 30% TBSA scald were enrolled in the study. Zamboni fixating solution was infused into left ventricle and the brain tissue was harvested at 4, 12 and 24 post-scald hours (PSH) for the detection of insulin expression with fluorescent immunohistochemistry, with 5 rats at each time-point. Another group of 10 rats were enrolled as controls.

RESULTSThere exhibited no obvious insulin expression in the brain tissue of rats in the control group. Insulin immune responsive positive cells were detected in the olfactory bulb and cerebral cortex of rats at 4 PBH. These cells were big with oval and fusiform shape, big, round, transparent nuclei, and prominent processes. The positive insulin substance was mainly distributed in cytoplasm, and some in the processes of cells. No insulin immune-responsive cells were observed in rat brain tissue at 12 and 24 PSH.

CONCLUSIONThe brain have the potentiality of self-biosynthesis of insulin, but very little of synthesized insulin exists in normal states, but the amount increases after scald.

Animals ; Brain ; metabolism ; Burns ; metabolism ; Disease Models, Animal ; Insulin ; biosynthesis ; Male ; Rats ; Rats, Wistar

Diabetes mellitus has become one of the most common chronic diseases, thereby posing a major challenge to global health. Characterized by high levels of blood glucose (hyperglycemia), diabetes usually results from a loss of insulin-producing β-cells in the pancreas, leading to a deficiency of insulin (type 1 diabetes), or loss of insulin sensitivity (type 2 diabetes). Both types of diabetes have serious secondary complications, such as microvascular abnormalities, cardiovascular dysfunction, and kidney failure. Various complex factors, such as genetic and environmental factors, are associated with the pathophysiology of diabetes. Over the past two decades, the role of small, single-stranded noncoding microRNAs in various metabolic disorders, especially diabetes mellitus and its complications, has gained widespread attention in the scientific community. Discovered first as an endogenous regulator of development in the nematode Caenorhabditis elegans, these small RNAs post-transcriptionally suppress mRNA target expression. In this review, we discuss the potential roles of different microRNAs in diabetes and diabetes-related complications.
Animals ; Diabetes Complications ; genetics ; metabolism ; Diabetes Mellitus ; genetics ; metabolism ; Glucose ; metabolism ; Homeostasis ; genetics ; Humans ; Insulin ; metabolism ; MicroRNAs ; biosynthesis ; genetics ; metabolism

OBJECTIVETo investigate the functional and metabolic alterations in cultured insulin resistant ovary model in vitro, and to observe the effect of berberine (Ber, a Chinese medical monomer) in improving insulin resistance (IR).

METHODSOvary of mouse was cultured in vitro and treated by dexamethasone (Dex) to induce IR for establishing IR model ovary. The functional alteration in model ovary was assessed through detecting glucose and hormone levels in medium using RT-PCR, meanwhile, the expression of key molecules in insulin signal and steroid synthetic pathway were detected, and condition of IR improved by berberine was evaluated also.

RESULTS(1) The model ovary was made by Dex in dose- and acting time-dependent manner. After being treated by 300 nmol/L Dex for 48 h, the glucose uptake of ovary reduced from 9.05 +/- 0.75 mg/g to 2.48 +/- 0.29 mg/g (P < 0.05); it further decreased (from 9.59 +/- 1.74 mg/g to 1.94 +/- 0.19 mg/g, P < 0.01) under the stimulation of insulin, which proved that the IR model ovary was made successfully. Berberine significantly increased the glucose uptake of model ovaries (1.89 +/- 0.33 mg/g to 13.95 +/- 3.30 mg/g, P < 0.05). (2) As compared with control group, levels of testosterone (T) and androstenedione (A2) were higher, and levels of progesterone (P) and 17-hydroxyprogesterone (17-OHP) were lower significantly in the model. Berberine reversed the alternations of T, A2 and 17-OHP levels, but did not influence the level of P. (3) RT-PCR showed that the mRNA expressions of cytochrome 17-hydroxylase (CYP17) and mini-chromosome maintenance protein-2 (MCM-2) elevated, but extracellular regulated protein-1 (ERK-1), protein kinase B (AKT-2) and glycogen synthase kinase-3 (GSK-3beta) lowered in the medium after Dex inducing. Berberine treatment restored these molecular index obviously.

CONCLUSIONS(1) Dex could induce IR in mouse ovary, which might enhance the androgenic synthesis. (2) Berberine could alleviate the degree of IR and the androgen synthesis, indicating that the Chinese sensitizing agents has favorable therapeutic effect for the treatment of polycystic ovaries.

17-alpha-Hydroxyprogesterone ; metabolism ; Androstenedione ; biosynthesis ; Animals ; Berberine ; pharmacology ; Female ; In Vitro Techniques ; Insulin ; metabolism ; Insulin Resistance ; Mice ; Mice, Inbred Strains ; Ovary ; drug effects ; metabolism ; Polycystic Ovary Syndrome ; Progesterone ; biosynthesis ; Testosterone ; biosynthesis

Swine is an ideal model for diabetes studies. Insulin and insulin resistance are closely related with diabetes. To investigate the effect of SOCS-3 in insulin resistance, porcine primary adipocyte was treated with insulin (100 nmol/L) and dexamethasone (300 nmol/L) to induce insulin resistance. The simi-quantitative PCR results suggested that insulin increased GLUT4, PPARgamma and SOCS-3 gene expression in primary culture porcine adipocytes and no change of OB gene expression. Under insulin resistance conditions, SOCS-3 and OB gene expression were up-regulated, whereas GLUT4 and PPARgamma gene expression were down-regulated in primary porcine adipocytes. The overexpression of PPARgamma gene resulted in the increase of GLUT4 expression by insulin. Different expression levels of SOCS-3 determined the inhibitory effects of insulin signaling. Induction of insulin resistance by dexamethasone was not only due to inhibition of glucose transportation, but also repression of insulin signaling. SOCS-3 might be a potential gene to block the insulin resistance.
Adipocytes ; cytology ; metabolism ; Animals ; Cells, Cultured ; Dexamethasone ; pharmacology ; Glucose Transporter Type 4 ; biosynthesis ; genetics ; Insulin ; pharmacology ; Insulin Resistance ; Leptin ; biosynthesis ; genetics ; PPAR gamma ; biosynthesis ; genetics ; Suppressor of Cytokine Signaling 3 Protein ; Suppressor of Cytokine Signaling Proteins ; biosynthesis ; genetics ; Swine

This study was intended to establish a method of preparation of recombinant human insulin, with (His)6-Arg-Arg-human proinsulin (RRhPI) expressed by Escherichia coli. After DEAE-Sepharose Fast Flow ion-exchange chromatography, Sephadex G-25 chromatography and refolding, enzyme cleavage and Superdex 75 size exclusion chromatography,the RRhPI expressed by Escherichia coli in inclusion body form was converted to human insulin. The obtained recombinant human insulin was analyzed by SDS-PAGE, HPLC, amino acid composition analysis and bioidentity test (mouse convulsion test). The results indicate that our obtained preparation is highly purified, active recombinant human insulin.
Chromatography, High Pressure Liquid ; Escherichia coli ; genetics ; metabolism ; Humans ; Insulin ; biosynthesis ; genetics ; isolation & purification ; Proinsulin ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics

To determine which genes are regulated by thyroid stimulating hormone (thyrotropin, TSH), insulin and insulin-like growth factor-1 (IGF-1) in the rat thyroid, we used the microarray technology and observed the changes in gene expression. The expressions of genes for bone morphogenetic protein 6, the glucagon receptor, and cyclin D1 were increased by both TSH and IGF-1; for cytochrome P450, 2c37, the expression was decreased by both. Genes for cholecystokinin, glucuronidase, beta, demethyl-Q 7, and cytochrome c oxidase, subunit VIIIa, were up-regulated; the genes for ribosomal protein L37 and ribosomal protein L4 were down-regulated by TSH and insulin. However, there was no gene observed to be regulated by all three: TSH, IGF-1, and insulin molecules studied. These findings suggest that TSH, IGF-1, and insulin stimulate different signal pathways, which can interact with one another to regulate the proliferation of thyrocytes, and thereby provide additional influence on the process of cellular proliferation.
Animals ; Bone Morphogenetic Protein 6 ; Bone Morphogenetic Proteins/biosynthesis ; Cell Line, Tumor ; Cyclin D1/biosynthesis ; *Gene Expression Profiling ; *Gene Expression Regulation ; Insulin/*biosynthesis/metabolism ; Insulin-Like Growth Factor I/*biosynthesis ; Models, Genetic ; *Oligonucleotide Array Sequence Analysis ; Rats ; Receptors, Glucagon/biosynthesis ; Thyroid Gland/*metabolism ; Thyrotropin/*biosynthesis/metabolism ; Time Factors

OBJECTIVETo explore the effects of berberine and insulin on adiponectin mRNA expression in 3T3-L1 adipocyte.

METHODThe 3T3-L1 adipocyte was treated with berberine and insulin for 48 hours, the level of adiponectin mRNA in 3T3-L1 adipocyte expression was determined with semiquantity RT-PCR using beta-actin as internal reference.

RESULTThe level of adiponetin mRNA in 3T3-L1 adipocyte was increased after treated with berberine only (P < 0.05), the effect of berberine was inhibited by high concentration insulin (P < 0.05).

CONCLUSIONIn vitro, berberine increases the expression of adiponectin in 3T3-L1 adipocyte, insulin inhibits the effect of berberine.

3T3-L1 Cells ; metabolism ; Adipocytes ; cytology ; metabolism ; Adiponectin ; Animals ; Berberine ; pharmacology ; Insulin ; pharmacology ; Intercellular Signaling Peptides and Proteins ; biosynthesis ; genetics ; Mice ; RNA, Messenger ; biosynthesis ; genetics

OBJECTIVETo investigate the molecular mechanism of the effect of alcohol on insulin sensitivity.

METHODSFour groups of Wistar rats were used, i.e. control (C) group, and low (L), moderate (M) and high (H) alcohol group. Alcohol doses of each group were 0, 0.6, 1.8 and 3.0 ml.(kg.bw)(-1).day(-1). Each group was comprised of 10 male and 10 female rats. Alcohol was given to rats by gastric intubation. Thirteen weeks later, serum was collected for testing of fasting plasma glucose and insulin. HOMA-IR index of each group were calculated. Total muscle RNA was extracted using Trizol Reagent (Promega). The expression level of IRS-1 mRNA in muscle was detected by RT-PCR.

RESULTSIn female rats, the fasting plasma glucose of group (8.36 +/- 0.57) mmol/L was higher and the fasting plasma insulin (15.25 +/- 3.32) was lower than those of group C (7.56 +/- 0.85, 20.80 +/- 3.25). The HOMA-IR of group L (1.775 3 +/- 0.138 1) was lower than that of group C (1.982 6 +/- 0.124 6) (P < 0.05), while IRS-1 mRNA (0.766 1 +/- 0.076 9) was up-regulated (P < 0.05); HOMA-IR of group M (2.202 2 +/- 0.271 0) was higher than that of group C (P < 0.01), while IRS-1 mRNA (0.501 8 +/- 0.049 2) was suppressed (P < 0.01); HOMA-IR of group H (1.850 1 +/- 0.162 8) was not significantly changed as compared with that of group C (1.982 6 +/- 0.124 6) (P > 0.05), while IRS-1 mRNA (0.418 1 +/- 0.049 1) was significantly suppressed (P < 0.01). In male rats, the fasting plasma glucose and insulin had the similar change as those of female rats. The HOMA-IR of group M (1.878 5 +/- 0.250 2) was lower than that of C group (2.147 3 +/- 0.330 8) (P < 0.05), IRS-1 mRNA was up-regulated (0.824 9 +/- 0.064 7) (P < 0.05).

CONCLUSIONSThe present study showed that low-to-moderate dose of alcohol could increase insulin sensitivity; while alcohol abuse could decrease insulin sensitivity. Sex difference in this effect was found. Changes of IRS-1 mRNA expression may be involved in the molecular mechanism of the effects of alcohol on insulin sensitivity.

Animals ; Dose-Response Relationship, Drug ; Ethanol ; pharmacology ; Female ; Insulin ; blood ; Insulin Receptor Substrate Proteins ; Insulin Resistance ; Male ; Muscle, Skeletal ; metabolism ; Phosphoproteins ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Up-Regulation

Mechano-growth factor (MGF) is one of IGF-1 isoforms. MGF is mechanosensitive and has important functions in muscle hypertrophy, regeneration and nerve injury recovery. In this study, MGF cDNA (330 bp) was cloned from stretched osteoblasts by RT-PCR. In order to avoid prolin residue inhibiting enterokinase cleavage, 9bp of MGF cDNA 5' end sequence was truncated by primer, then the obtained truncated MGF (des(1-3)MGF) cDNA (321 bp) was subcloned in pET32a(+) vector to construct a prokaryotic recombination expression plasmid. Trx/des(1-3)MGF fusion protein, existing in forms of solution, was expressed in transformed Escherichia coli strain BL21(DE3) by IPTG induction at 30 degres C. The supernatant of cell lysates was subjected to ion exchange chromatography and Ni2+ metal affinity chromatography, and the fusion protein was obtained with the purity over 95%. After the fusion protein was cleaved by enterokinase, Trx and des(1-3)MGF was isolated by reverse-phase HPLC. Through these procedures, des(1-3) MGF was obtained with the purity of 98%. The protein molecular mass was conformity to the theoretical value by SDS-PAGE and mass spectrometry analysis. The purified des(1-3)MGF was incubated with MC3T3-E1 for cell proliferation and migration assays. The results show that des(1-3)MGF exhibited more facilitative effects on proliferation and migration of MC3T3-E1 than that of des(1-3)IGF-1.
Cloning, Molecular ; DNA, Complementary ; genetics ; Escherichia coli ; genetics ; metabolism ; Humans ; Insulin-Like Growth Factor I ; Osteoblasts ; metabolism ; Protein Isoforms ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; pharmacology ; STAT5 Transcription Factor ; biosynthesis ; genetics ; Tumor Suppressor Proteins ; biosynthesis ; genetics