Short report: Tissue-specific expression profiles of the uncoupling protein family in normal control mice and genetically ob/ob mice

Uncoupling proteins (UCPs) located in the inner mitochondrial membrane are involved in the regulation of energy balance. Thus far, 5 UCP isoforms have been identified, but controversies exist in the research focused on the function of the UCPs (except UCP1) in the pathogenesis of obesity. Because of the known cross-reactivity of the antibodies presently available for the detection of UCP proteins, this study systematically analyzed the differential tissue expression profiles of the 5 UCP isoforms in lean control mice and ob/ob mice by using real-time polymerase chain reaction (PCR) analysis. The results show that the tissue-specific expression patterns of individual isoforms in normal and ob/ob mice are considerably different; this will provide new insights into the functions of UCPs in the pathogenesis of genetic obesity.

Mitochondrial dysfunction is induced by high levels of glucose and free fatty acids in 3T3-L1 adipocytes

Hyperglycemia and high free fatty acids (FFAs) are two well-known characteristics of type 2 diabetes, and are also implicated in the etiology of insulin resistance. However, their roles in mitochondrial dysfunction of white adipocytes are not well-studied. In this study, we investigated the effects of high glucose (25 mM), high free fatty acids (FFAs, 1mM), or a combination of both high glucose+high FFAs on mitochondrial function in differentiated 3T3-L1 adipocytes after 48 h of treatment. We found that high glucose, high FFAs, or high glucose+high FFAs reduced insulin-stimulated glucose uptake in differentiated 3T3-L1 adipocytes. In addition, the mitochondria became smaller and more compact. Levels of the mitofusion protein mfn1 decreased and levels of the mitofission protein Drp1 increased as compared to controls. NRF1 was downregulated, and PGC-1 beta levels were diminished in the high glucose and high glucose+high FFAs conditions. Levels of PGC-1 alpha and mtTFA mRNA were greatly downregulated. No difference was found in the mitochondrial DNA (mtDNA) and intracellular ATP levels of treated cells compared to control cells. Cells treated with high glucose or high FFAs accumulated significant amounts of reactive oxygen species (ROS) and displayed a loss of the mitochondrial membrane potential. High glucose and high glucose+high FFAs led to similar decreases in intramitochondrial calcium concentration, although high FFAs had no effect. Therefore, high glucose and high FFAs can regulate insulin sensitivity, and mitochondrial dysfunction may occur in this process.

Resveratrol attenuates radiation damage in Caenorhabditis elegans by preventing oxidative stress

Resveratrol, a member of a class of polyphenolic compounds known as flavonols, has been extensively studied for its anticancer, antiviral, anti-inflammatory, and neuroprotective roles. Caenorhabidits elegans is a well-established animal for investigating responses to radiation. We found that resveratrol may provide protection against hazardous radiation. Pre-treatment with resveratrol extended both the maximum and mean life span of irradiated C. elegans. Resveratrol acted as a strong radical scavenger and regulated superoxide dismutase (SOD) expression. In addition, resveratrol was shown to be capable of alleviating gamma-ray radiation exposure-induced reduction in mitochondrial SOD expression. Ultimately, a correlation may exist between dietary intake of trace amounts of resveratrol and anti-aging effects. A specific response mechanism may be activated after the administration of resveratrol in irradiated animals. Our results suggest the protective effect of resveratrol is due to its strong ability to protect from oxidative stress and protective effects in mitochondria. Therefore, resveratrol is potentially an effective protecting agent against irradiative damage.

[Resistin inhibits rat insulinoma cell RINm5F proliferation]

OBJECTIVE

Resistin was thought to link the obesity to type 2 diabetes. This study aimed to investigate the effect of resistin on insulinoma cell proliferation.

METHODS

pcDNA3.1-resistin was transfected into rat insulinoma cells RINm5F. Cell proliferation was assessed by the MTT assay. The resistin and SOCS3 mRNA levels were assessed by RT-PCR. The total Akt level and the phosphorylation status were assessed by Western blot.

RESULTS

The over-expressed resistin inhibited the RINm5F cell proliferation (p<0.05). SOCS-3 expression was up-regulated by resistin over-expression (3.2 folds over the control; p<0.05). Akt phosphorylation was down-regulated by resistin over-expression (0.6 fold over the control; p<0.05).

CONCLUSIONS

Resistin impairs the rat insulinoma cell RINm5F proliferation. This might be attributed to a down-regulation of Akt level caused by increased SOCS-3 expression.

Mitochondrial dysfunction is induced by the overexpression of UCP4 in 3T3-L1 adipocytes

Uncoupling proteins (UCPs) belong to a superfamily of mitochondrial transporters that uncouple ATP synthesis from electron transport. We have previously shown that uncoupling protein 4 (UCP4) is differentially expressed in omental adipose tissue in diet-induced obese and normal rats. Overexpression of UCP4 promotes proliferation and inhibits apoptosis and differentiation of preadipocytes. In this work, we further characterized the effect of UCP4 on mitochondrial function in mature 3T3-L1 adipocytes. Transmission electron microscopy (TEM) showed that adipocytes overexpressing UCP4 displayed condensed mitochondria with twisted, condensed, and unclear cristae. Moreover, the loss of the mitochondrial membrane potential and intramitochondrial calcium was found. The adipocytes overexpressing UCP4 also showed decreased mitochondrial copy number (mtDNA) and lower mRNA expression of key factors in mitochondrial biogenesis, including PGC-1alpha and mtTFA. NRF-1 and ERRbeta levels were down-regulated, while NRF-2 levels were upregulated. In addition, UCP4 overexpression impaired mitochondrial fusion and fission, as indicated by decreased mitofusin mfn1, mfn2, and mitofission DRP1. When it came to total adipocytes, the UCP4 overexpressing adipocytes showed higher production reactive oxygen species and diminished levels of intracellular ATP. Furthermore, overexpression of UCP4 brought about impaired insulin sensitivity in adipocytes. UCP4 plays an important role in mitochondrial function and adipocyte insulin resistance. Its function deserves further attention.

Spinal macrophage migration inhibitory factor contributes to the pathogenesis of inflammatory hyperalgesia in rats

Pro-inflammatory cytokine production after nociceptive stimuli is pivotal for hyperalgesia. As macrophage migration inhibitory factor (MIF), a pleiotropic cytokine produced mainly by nonneuronal tissue, has been involved in the regulation of neuronal functions, herein we examined the role for MIF in formalin-induced inflammatory pain model. MIF critically contributed to nociceptive behaviors following formalin injection. Specifically, spinal administration of a MIF inhibitor (ISO-1) prevented and reversed flinching responses in rats. Further examination showed that levels of both MIF and the MIF receptor CD74 were substantially increased within the ipsilateral spinal cord dorsal horn after formalin administration. Mechanistic studies revealed that MIF upregulated the expression of the spinal NMDA receptor subunit NR2B via the MAPK signaling pathway. Moreover, microglial cells were found to be the major source of spinal MIF after formalin administration by fluorescence colocalization. These data highlight spinal MIF plays a critical role in the pathogenesis of formalin-induced inflammatory pain and suggest MIF may be a potential target for therapy of such pathological condition.

[Regulative role of TNFalpha on STEAP4 gene in matured human adipocytes]

OBJECTIVE

Human STEAP4, a novel obesity-related gene, is associated with insulin sensitivity regulation in human adipocytes. This study aimed to explore the regulative role of TNFalpha on STEAP4 gene in matured human adipocytes.

METHODS

Human preadipocytes were cultured and differentiated into matured adipocytes in vitro. Fully differentiated adipocytes (Day 17) were treated with different concentrations of TNFalpha (0, 5, 10, 25 and 50 ng/mL) for 24 hrs. Total RNA and protein were extracted from the adipocytes. Levels of STEAP4 mRNA and protein expression were determined by real-time quantitative RT-PCR and Western blot respectively.

RESULTS

Different concentrations (5, 10, 25 and 50 ng/mL) of TNFalpha treatment for 24 hrs resulted in a significant increase in the STEAP4 mRNA expression of human matured adipocytes.The maximal effect was seen in the 50 ng/mL of TNFalpha treatment group. In parallel, STEAP4 protein synthesis in matured adipocytes increased in response to TNFalpha treatment of different concentrations (5, 10, 25 and 50 ng/mL) for 24 hrs. The maximal up-regulated effect was seen in the 25 ng/mL of TNFalpha treatment group.

CONCLUSIONS

TNFalpha can up-regulate STEAP4 mRNA expression in human matured adipocytes.

Tissue-specific distribution of uncoupling proteins in normal rats and rats with high-fat-diet-induced obesity

Uncoupling proteins (UCPs) are a proton transporter family located in the mitochondrial inner membrane. Thus far, five molecules (UCP1-UCP5) have been identified as members of the UCP family. Recently, UCPs have attracted considerable interest in research on energy metabolism and obesity. However, to date, no study has focused on a comprehensive and systematic evaluation of the tissue-specific distribution of UCPs in obese individuals. Our study presents evidence of differential tissue expression profiles of five isoforms of UCPs in normal and diet-induced obese (DIO) rats using real-time polymerase chain reaction (PCR) analysis. The results clearly show that the tissue-specific expression patterns of individual isoforms between DIO and normal rats are quite distinct, which suggests a close relationship between the alterations in UCP expression and dietary obesity.

[Effects of NYGGF4 gene over-expression on the insulin sensitivity and secretory function of adipocytes]

OBJECTIVE

To study the effect of a new obesity-related gene NYGGF4 on the insulin sensitivity and secretory function of adipocytes.

METHODS

3T3-L1 preadipocytes transfected with either an empty expression vector (pcDNA3.1; control group) or an NYGGF4 expression vector (NYGGF4-pcDNA3.1) were cultured in vitro and differentiated into the matured adipocytes with the standard insulin plus dexamethasone plus 3-isobutyl-methylxanthine (MDI) induction cocktail. 2-deoxy-D-[3H] glucose uptake was determined by liquid scintillation counting. Western blot was performed to detect the protein content and translocation of glucose transporter 4 (GLUT4). The supernatant concentrations of TNF-alpha, IL-6, adiponectin and resistin were measured using ELISA.

RESULTS

NYGGF4 over-expression in 3T3-L1 adipocytes reduced insulin-stimulated glucose uptake. NYGGF4 over-expression impaired insulin-stimulated GLUT4 translocation without affecting the total protein content of GLUT4. The concentrations of TNF-alpha, IL-6, adiponectin and resistin in the culture medium of 3T3-L1 transfected with NYGGF4 were not significantly different from those in the control group.

CONCLUSIONS

NYGGF4 over-expression impairs the insulin sensitivity of 3T3-L1 adipocytes through decreasing GLUT4 translocation and had no effects on the secretory function of adipocytes.

[Construction of eukaryotic expression vector of LYRM1, a novel gene related with human obesity, and establishment of its stable transfected 3T3-L1 cell line]

OBJECTIVE

To construct the eukaryotic expression vector of LYRM1 and to transfect it to preadipocytes cell line 3T3-L1.

METHODS

The complete coding sequence of LYRM1 gene was amplified by RT-PCR from human omental adipose tissue and was subcloned into eukaryotic expression vector pcDNA(TM)3.1/myc-His B. The recombinant plasmid was then transfected into 3T3-L1 preadipocytes by liposome. After screening culture by G418, stable transfected 3T3-L1 cell line was established. The expression of LYRM1 protein was identified by Western blot.

RESULT

The recombinant plasmid was confirmed by PCR, restriction enzyme digestion and sequencing. The stable transfected 3T3-L1 cell line was established and the LYRM1 protein was expressed successfully.

CONCLUSION

The eukaryotic expression vector of LYRM1 has been successfully established and the stably transfected 3T3-L1 cell line also established.

Folbp1 promotes embryonic myocardial cell proliferation and apoptosis through the WNT signal transduction pathway

The aim of this study was to evaluate the relationship between Folate-binding protein one (Folbp1) and embryonic cardiac proliferation, apoptosis, and differentiation. Folbp1 gene expression and short interference RNA expression vectors were constructed. Morphology of P19 cells during differentiation was observed by inverted microscope. Cell proliferation was tested using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazoliumbromide (MTT) method. Cell apoptosis was evaluated by DNA ladder and flow cytometry methods, and marker gene expression during differentiation, such as atrial natriuretic peptide (ANP) and cardiac troponin I (cTnI), and marker gene expression during apoptosis (Bax/Bcl-2) was measured by RT-PCR. Additionally, the critical genes (Wnt, GSK3beta, and/or beta-catenin) expressed in the Wnt signaling pathway were confirmed by RT-PCR. The Folbp1 expressing vector and the silencing vector were constructed. From day 5 of differentiation, the absorbance of cells overexpressing Folbp1 was notably higher than the controls, whereas the controls were notably higher than Folbp1 gene silenced P19 cells. P19 cell apoptosis with Folbp1 gene silencing was lower than the controls; however, more cells were driven into S phase. No significant morphological difference was observed in any of the groups. RT-PCR results show that ANP, cTnI, Wnt, Bax/Bcl-2, and beta-catenin were elevated whereas GSK3beta depressed in cells which overexpressed Folbp1 and was contradictory in Folbp1 gene silenced P19 cells. Folbp1 may be an important candidate mediator of folic acid deficiency-induced congenital cardiac anomalies which are induced by the dysfunction of proliferation and apoptosis of the myocardial cell, and possibly caused by the dysfunction of the Wnt signaling pathway.

LYRM1, a novel gene promotes proliferation and inhibits apoptosis of preadipocytes

OBJECTIVE

To characterize a novel gene, Homo sapiens LYR motif containing 1 (LYRM1), that is highly expressed in omental adipose tissue of obese subjects.

METHODS AND RESULTS

RT-PCR and western blot analysis confirmed that both mRNA and protein levels of LYRM1 were higher in omental adipose tissue of obese subjects than in normal weight subjects. RT-PCR analysis demonstrated that LYRM1 expression is widely distributed, with the highest levels of expression occurring in adipose tissue. A fusion protein of LYRM1 and green fluorescent protein as well as western blot analysis were used to identify the subcellular localization of LYRM1 in the nucleus. Based on Oil red O staining and the expression profile of specific differentiation markers, ectopic LYRM1 expression was not found to significantly affect adipogenesis. MTT assays and cell cycle analysis showed that LYRM1 promotes preadipocyte proliferation, and data from annexin V-FITC and caspase-3 activity assays further determined that LYRM1 can inhibit apoptosis of preadipocytes.

CONCLUSIONS

By increasing cell proliferation and lowering the rate of apoptosis, LYRM1 has the potential to modulate the size of the preadipocyte pool and influence adipose tissue homeostasis.

Gene expression profiles of adipose tissue of obese rats after central administration of neuropeptide Y-Y5 receptor antisense oligodeoxynucleotides by cDNA microarrays

To investigate the gene expression profiles of adipose tissue of obese rats after central administration of neuropeptide Y-Y5 receptor antisense oligodeoxynucleotides (ODNs), Y5 receptor antisense, mismatched ODNs or vehicle was intracerebroventricularly injected and cDNA microarrays were undertaken. Central administration of NPY-Y5 receptor antisense ODNs decreased food intake, body weight and serum insulin compared with both vehicle and mismatched ODNs. The average area of adipocytes both at retroperitoneal and epididymal adipose tissue were fall in antisense group while only the weight of the retroperitoneal fat pats was reduced in antisense group. cDNA microarrays containing 18,000 genes/Ests were used to investigate gene expression of adipose tissue. Autoradiographic analysis showed that 404, 81, and 34 genes were differently expressed over twofold, threefold, and fivefold, respectively. The analysis of gene expression profiles indicated that 332 genes were up-regulated and 187 genes were down-regulated in response to Y5 receptor antisense ODNs treatment. Different clusters of genes associated with apoptosis, signal transduction, energy metabolism, lipid metabolism, etc., such as FXR1, PHLDA1, MAEA, PIK3R1, ICAM2, PITPN, CALM2, CAMK2D, PKIA, DRD2, SLC25A14, CKB, AADAC, LIPA, ACOX3, FADS1, were concerned. Analysis of differentially expressed genes will help to understand the effects of Y5 receptor antisense ODNs therapy.

Downregulation of STEAP4, a highly-expressed TNF-alpha-inducible gene in adipose tissue, is associated with obesity in humans

AIM

To determine the relationship between six-transmembrane epithelial antigen of the prostate 4 (STEAP4) expression and obesity.

METHODS

RT-PCR and immunoblot analyses were performed to determine the differential expressions of STEAP4 mRNA and protein, respectively, in human omental adipose tissue from obese patients and normal weight controls. The expression pattern of STEAP4 mRNA in various human tissues was determined by RT-PCR. The subcellular localization of the STEAP4 protein in human adipose tissue was confirmed by immunohistochemistry. Finally, we confirmed that cultured human omental adipose tissue undergoes TNF-alpha-mediated regulation of the STEAP4 expression.

RESULTS

STEAP4 mRNA and protein levels were downregulated in omental adipose tissue from obese patients relative to normal controls. The STEAP4 expression was most abundant in human adipose tissue. An immunohistochemical analysis confirmed that STEAP4 was associated with the plasma membrane of adipocytes. The STEAP4 expression was induced by TNF-alpha in a dose-dependent manner in human adipose tissue.

CONCLUSION

STEAP4 was abundantly expressed in human adipose tissue, and the STEAP4 expression was significantly downregulated in obese patients. STEAP4 localized to the plasma membrane of adipocytes, and the STEAP4 expression was induced by TNF-alpha in adipose tissue. These data suggest that STEAP4 may play a significant role in the development of human obesity.

[Evidence of inhaled nitric oxide therapy for hypoxic respiratory failure in term and near-term infants]

OBJECTIVE

To study the evidence-based therapy of inhaled nitric oxide (iNO) for hypoxic respiratory failure (HRF) in term and near-term infants by analyzing the literature systematically.

METHODS

The literature related to the treatment of HRF with iNO was retrieved from the following: PubMed, EMBASE, OVID, Springer and Chinese Journals Full-Text Database (CNKI). The relevant literature on randomized controlled trials (RCTs) that met the criteria was statistically analyzed by the software of Review Manager 4.2, as recommended by Cochrane Collaboration.

RESULTS

A total of 162 articles were retrieved. Fifteen met the criteria and were selected for Meta analysis (4 single center and 11 multicenter randomized trials). Meta analysis showed that 30-60 minutes iNO therapy decreased the oxygenation index (P<0.05), increased PaO2 significantly, and reduced need of extracorporeal membrane oxygenation(ECMO) (P<0.05). However, for the neonates with HRF caused by congenital diaphragmatic hernia, iNO therapy did not result in a significant reduction in the oxygenation index and death rate. There was no significant difference in the occurrence of neurodevelopmental sequelae between the iNO and control groups.

CONCLUSIONS

The currently published evidence from RCTs supports the use of iNO in term and near-term infants with HRF but except for the HRF infants caused by diaphragmatic hernia. The effect of iNO therapy on long-term neurodevelopment needs to be further studied.

CREB and Sp1 regulate the human CD2AP gene promoter activity in renal tubular epithelial cells

The human CD2-associated protein (CD2AP) is involved in several molecular signaling pathways and is an important factor responsible for nephrotic syndrome. Here we report the identification of the transcription start point and promoter region of the human CD2AP gene in renal tubular epithelial cells. With luciferase assays and deletion analysis, we found that the region between -558 and -1bp ahead of the transcription start point is indispensable for the promoter activity of the human CD2AP gene. A CREB site and two Sp1 sites were essential for maintaining the basal transcriptional activity of the human CD2AP promoter. Overexpression of phosphorylated CREB and Sp1 transactivated the human CD2AP promoter, whereas small interfering RNA-mediated blockage of CREB and Sp1 genes expressions inhibited markedly its activity. These findings provide the first analysis of the human CD2AP gene promoter and demonstrate that not only CREB but also Sp1 plays a critical role in regulating basal CD2AP promoter activity in renal tubular epithelial cells.

[Effects of Par-4 gene silencing induced by siRNA on the expression of Smac gene, activity of caspase-3, and apoptosis of human bone marrow mesenchymal stem cells]

OBJECTIVE

To investigate the effects of Par-4 gene silencing induced by siRNA on the expression of Smac gene, activity of caspase-3, and apoptosis of human bone marrow mesenchymal stem cells (hBMSCs).

METHODS

Bone marrow was obtained from a healthy young man and hBMSCs were isolated and cultured. Two siRNAs (Par-4-siRNA-1 and -2) targeting Par-4 gene were chemically synthesized. Eukaryocytic expression vectors containing these Par-4 siRNA sequences were established and transfected into the hBMSCs. The hBMSCs were divided into 4 groups: non-transfected hBMSCs (normal control group), blank Pae-4 plasmid transfected hBMSCs (Par4 control group), Par4-siRNA-1 transfected hBMSCs, and Par-4-siRNA-2 transfected hBMSCs. The expression of Par-4 mRNA was detected by real-time PCR. Another hBMSCs were inoculated in DMEM and divided into 4 groups: non-transfected normal hBMSCs, glutamate (an apoptosis inducer) + non-transfected hBMSC group, glutamine + Par-4-siRNA-1 hBMSC group, and glutamate + Par4-SiRNS-2 hBMSC group. Flow cytometry was used to detect the apoptotic rate. The relative activity of caspase-3 was determined by colorimetric assay. Western blotting was used to detect the Smac protein expression.

RESULTS

The relative mRNA expression levels of Par-4 gene of the Par-4-siRNA-1 hBMSCs, Par-4 SiENA-2 hBMSCs, and Par-4 control hBMSCs were 0.12 +/- 0.03, 0.33 +/- 0.09, and 0.97 +/- 0.02 respectively, decreased by 88%, 67%, and 3% respectively compared with that of the normal control. The percentages of apoptotic cells of the glutamate + Par-4-siRNA-1 hBMSCs was (37.2 +/- 6.3)%, significantly lower than that of the glutamate + non-transfected hBMSC group [(58.9 +/- 8. 9)%, F = 58.26, P < 0.01). The Smac protein expression level of the glutamate + non-transfected hBMSC group was significantly higher than that of the normal control group (P < 0.01); however, the Smac protein expression level of the Par-4-siRNA-1 hBMSC group was significantly lower than that of the glutamate + non-transfected hBMSC group (P < 0.01). The caspase-3 activity of the glutamate + Par-4-siRNA-1 hBMSC group was significantly lower than that of the glutamate + non-transfected BMSC group (P < 0.01).

CONCLUSION

Par-4-siRNA-1 inhibits markedly the apoptosis of the hBMSCs induced by glutamate. Par-4 gene silencing induced by siRNA inhibits the apoptosis of hBMSCs. The mechanism of the inhibition may be closely related to suppression of the up-regulation of Smac gene expression and caspase-3 activity.

A paradox: Insulin inhibits expression and secretion of resistin which induces insulin resistance

AIM: To confirm whether insulin regulates resistin expression and secretion during differentiation of 3T3-L1 preadipocytes and the relationship of resistin with insulin resistance both in vivo and in vitro.

METHODS: Supernatant resistin was measured during differentiation of 3T3-L1 preadipocytes. L6 rat myoblasts and hepatoma cell line H4IIE were used to confirm the cellular function of resistin. Diet-induced obese rats were used as an insulin resistance model to study the relationship of resistin with insulin resistance.

RESULTS: Resistin expression and secretion were enhanced during differentiation 3T3-L1 preadipocytes. This cellular differentiation stimulated resistin expression and secretion, but was suppressed by insulin. Resistin also induced insulin resistance in H4IIE hepatocytes and L6 myoblasts. In diet-induced obese rats, serum resistin levels were negatively correlated with insulin sensitivity, but not with serum insulin.

CONCLUSION: Insulin can inhibit resistin expression and secretion in vitro, but insulin is not a major regulator of resistin in vivo. Fat tissue mass affects insulin sensitivity by altering the expression and secretion of resistin.

Prolonged exposure to resistin inhibits glucose uptake in rat skeletal muscles

AIM

To assess the effects and mechanisms of the action of resistin on basal and insulin-stimulated glucose uptake in rat skeletal muscle cells.

METHODS

Rat myoblasts (L6) were cultured and differentiated into myotubes followed by stimulation with single commercial resistin (130 ng/mL, 0-24 h) or cultured supernatant from 293-T cells transfected with resistin-expressing vectors (130 ng/mL, 0-24 h). Liquid scintillation counting was used to quantitate [3H] 2-deoxyglucose uptake. The translocation of insulin-sensitive glucose transporters GLUT4 and GLUT1, synaptosomal-associated protein 23 (SNAP23) and GLUT protein content, as well as the tyrosine phosphorylation status and protein content of insulin receptor substrate (IRS)-1, were assessed by Western blotting.

RESULTS

Treatment of L6 myotubes with single resistin or cultured supernatant containing recombinant resistin reduced basal and insulin-stimulated 2-deoxyglucose uptake and impaired insulin-stimulated GLUT4 translocation. While SNAP23 protein content was decreased, no effects were noted in GLUT4 or GLUT1 protein content. Resistin also diminished insulin-stimulated IRS-1 tyrosine phosphorylation levels without affecting its protein content. The effects of recombinant resistin from 293-T cells transfected with resistin-expressing vectors were greater than that of single resistin treatment.

CONCLUSION

Resistin regulated IRS-1 function and decreased GLUT4 translocation and glucose uptake in response to insulin. The downregulated expression of SNAP23 may have been partly attributed to the decrease of glucose uptake by resistin treatment. These observations highlight the potential role of resistin in the pathophysiology of type 2 diabetes related to obesity.

Lipolysis and apoptosis of adipocytes induced by neuropeptide Y-Y5 receptor antisense oligodeoxynucleotides in obese rats

AIM

To investigate the influence of central administration of neuropeptide Y-Y5 receptor antisense oligodeoxynucleotides (ODN) on the body weight and fat pads of high-energy diet-induced obese rats, and the effects on white adipocyte lipolysis and apoptosis.

METHODS

Y5 receptor antisense, sense, mismatched oligodeoxynucleotides (ODN) or vehicle were intracerebroventricularly injected, and average adipocyte area was calculated. DNA ladders were measured to evaluate adipocyte apoptosis, and RT-PCR was used to analyze the expression of bcl-2 and bax gene.

RESULTS

(1) Central administration of Y5 receptor antisense ODN significantly decreased body weight, fat pads, and average adipocyte area. (2) DNA fragmentation was presented after electrophoresis at both epididymal and retroperitoneal adipose tissue. (3) The expression of bcl-2 gene was downregulated, while the expression of bax was upregulated.

CONCLUSION

Lipolysis and adipocyte apoptosis may be important reasons for Y5 receptor antisense therapy.

Multiresolution wavelet analysis of evoked potentials

Neurological injury, such as from cerebral hypoxia, appears to cause complex changes in the shape of evoked potential (EP) signals. To characterize such changes we analyze EP signals with the aid of scaling functions called wavelets. In particular, we consider multiresolution wavelets that are a family of orthonormal functions. In the time domain, the multiresolution wavelets analyze EP signals at coarse or successively greater levels of temporal detail. In the frequency domain, the multiresolution wavelets resolve the EP signal into independent spectral bands. In an experimental demonstration of the method, somatosensory EP signals recorded during cerebral hypoxia in anesthetized cats are analyzed. Results obtained by multiresolution wavelet analysis are compared with conventional time-domain analysis and Fourier series expansions of the same signals. Multiresolution wavelet analysis appears to be a different, sensitive way to analyze EP signal features and to follow the EP signal trends in neurologic injury. Two characteristics appear to be of diagnostic value: the detail component of the MRW displays an early and a more rapid decline in response to hypoxic injury while the coarse component displays an earlier recovery upon reoxygenation.

[Condition of the serum antioxidation in normal pregnant women]

In order to investigate the condition of antioxidation in normal pregnancy, the serum levels of antioxidant activity (AOA), superoxide dismutase (SOD) activity, uric acid and vitamin C were measured in 30 cases of normal pregnant women. The results showed that the serum levels of AOA and SOD activity (nitrite unit per mg serum protein) were significantly higher than that of non-pregnant women (P < 0.01 and P < 0.005), and indicated that the serum condition of antioxidation was improved during the normal pregnancy. Besides, serum vitamin C level decreased and uric acid level remained unchanged. The SOD activity unit were also discussed.

Orthonormal (Fourier and Walsh) models of time-varying evoked potentials in neurological injury

Estimation of time-varying changes in evoked potentials (EP's) has important applications, such as monitoring high-risk neurosurgical procedures. We test the hypothesis that injury related changes in EP signals may be modeled by orthonormal basis functions. We evaluate two models of time-varying EP signals: the Fourier series model (FSM) and the Walsh function model (WFM). We estimate the Fourier and Walsh coefficients with the aid of an adaptive least-mean-squares technique. Results from computer simulations illustrate how selection of model order and of the adaptation rate of the estimator affect the signal-to-noise ratio (SNR). The FSM results in a somewhat higher steady-state SNR than does the WFM; however, the WFM is less computationally complex than is the FSM. We apply these two orthonormal functions to evaluate transient response to hypoxic hypoxia in anesthetized cats. Trends of the first five frequencies (Fourier) and sequencies (Walsh) show that the lower frequencies and sequencies may be sensitive indicators of hypoxic neurological injury.

[Clinical features and prognosis of retinal lattice degeneration]

110 cases (110 eyes) of retinal lattice degeneration were clinically observed and followed up for 3-8 years. Most lesions were located in the superotemporal quadrant, band-shaped, and parallel to the ora serrata. 80.9% of the lesions presented various degrees of pigmentation, 67.1% yellowish white spots, and 83.6% white lines. 32.9% of the eyes developed retinal holes. Most lattice degenerations were accompanied by vitreous degeneration and vitreoretinal traction. The disease progressed only slowly, though in a few cases it tended to expand.