Nucleobindin-2 is a positive modulator of EGF-dependent signals leading to enhancement of cell growth and suppression of adipocyte differentiation

Nesfatin-1 and nesfatin-1-like peptide attenuate hepatocyte lipid accumulation and nucleobindin-1 disruption modulates lipid metabolic pathways

Nesfatin-1 (NESF-1) has been shown to modulate lipid metabolism. We have identified a nesfatin-1-like-peptide (NLP) processed from a related precursor nucleobindin 1 (NUCB1). Here we determined if NLP, like NESF-1, regulates lipid accumulation in vitro, and tested if the disruption of nucb1 gene affects hepatic lipid metabolism genes in mice. Hepatocytes (HepG2/C3A cells) express NLP and NESF-1 and both peptides significantly reduced lipogenic enzyme mRNAs and enhanced beta-oxidation enzyme mRNAs. Lipid contents in oleic acid induced HepG2/C3A cells were attenuated by NESF-1 and NLP. The inhibitory effect on cellular lipid content was blocked by compound C, an inhibitor of AMPK. The disruption of nucb1 gene affected lipid metabolism-related enzyme mRNAs, endogenous nucb2 mRNA and AMPK phosphorylation. The lipid-lowering effects identified here highlights the potential of nucleobindins and peptides processed from them to address lipid disorders, and its possible benefits in metabolic disease management.

Nuclear Binding Protein 2/Nesfatin-1 Affects Trophoblast Cell Fusion during Placental Development via the EGFR-PLCG1-CAMK4 Pathway

Previous studies have shown that nuclear binding protein 2 (NUCB2) is expressed in the human placenta and increases with an increase in the syncytialization of trophoblast cells. This study aimed to investigate the role of NUCB2 in the differentiation and fusion of trophectoderm cells. In this study, the expression levels of NUCB2 and E-cadherin in the placentas of rats at different gestation stages were investigated. The results showed that there was an opposite trend between the expression of placental NUCB2 and E-cadherin in rat placentas in different trimesters. When primary human trophoblast (PHT) and BeWo cells were treated with high concentrations of Nesfatin-1, the trophoblast cell syncytialization was significantly inhibited. The effects of NUCB2 knockdown in BeWo cells and Forskolin-induced syncytialization were investigated. These cells showed a significantly decreased cell fusion rate. The mechanism underlying NUCB2-regulated trophoblast cell syncytialization was explored using RNA-Seq and the results indicated that the epidermal growth factor receptor (EGFR)-phospholipase C gamma 1 (PLCG1)-calmodulin-dependent protein kinase IV (CAMK4) pathway might be involved. The results suggested that the placental expression of NUCB2 plays an important role in the fusion of trophoblasts during differentiation via the EGFR-PLCG1-CAMK4 pathway.

Does NUCB2/Nesfatin-1 Influence Eating Behaviors in Obese Patients with Binge Eating Disorder? Toward a Neurobiological Pathway

Nesfatin-1 is a new anorexigenic neuropeptide involved in the regulation of hunger/satiety, eating, and affective disorders. We aimed to investigate nesfatin-1 secretion in vitro, in murine adipose cells, and in human adipose fat samples, as well as to assess the link between circulating nesfatin-1 levels, NUCB2 and Fat Mass and Obesity Gene (FTO) polymorphisms, BMI, Eating Disorders (EDs), and pathological behaviors. Nesfatin-1 secretion was evaluated both in normoxic fully differentiated 3T3-L1 mouse adipocytes and after incubation under hypoxic conditions for 24 h. Omental Visceral Adipose tissue (VAT) specimens of 11 obese subjects, and nesfatin-1 serum levels' evaluation, eating behaviors, NUCB2 rs757081, and FTO rs9939609 polymorphisms of 71 outpatients seeking treatment for EDs with different Body Mass Index (BMI) were studied. Significantly higher levels of nesfatin-1 were detected in hypoxic 3T3-L1 cultured adipocytes compared to normoxic ones. Nesfatin-1 was highly detectable in the VAT of obese compared to normal-weight subjects. Nesfatin-1 serum levels did not vary according to BMI, sex, and EDs diagnosis, but correlations with grazing; emotional, sweet, and binge eating; hyperphagia; social eating; childhood obesity were evident. Obese subjects with CG genotype NUCB2 rs757081 and AT genotype FTO rs9939609 polymorphisms had higher nesfatin-1 levels. It could represent a new biomarker of EDs comorbidity among obese patients.

Zinc Supplementation Improved Neuropeptide Y, Nesfatin-1, Leptin, C-reactive protein, and HOMA-IR of Diet-Induced Obese Rats

Obesity is a mild chronic inflammation that causes many metabolic diseases. It was aimed to investigate some parameters affective on the energy metabolism by adding zinc (Zn, ZnSO4) to drinking water of diet-induced obese rats. Five-week aged, male Sprague Dawley rats divided into as control group, consuming standard rat diet, and high-fat diet (HFD) group. After obesity induced by feeding HFD for 8 weeks, the obese rats were divided into Zn-supplemented obese group (HFD + obese + Zn; 150 mg Zn/L (for 6 weeks), 235 mg Zn/L (7th week), 250 mg Zn/L (8th week) in drinking water) and obese group (HFD + obese). Mean body weight, serum concentrations of C-reactive protein, neuropeptide-Y, leptin, insulin fasting blood glucose, and HOMA-IR were statistically decreased by given Zn in HFD + obese + Zn group compared to HFD + obese rats. It was observed that the total cholesterol, LDL, and HDL cholesterol levels of HFD + obese + Zn group became closer to the control group level, and Zn supplementation caused a statistically significant decrease in cholesterol profile than HFD + obese rats. Also, increased mean serum nesfatin-1 level, an effective protein for the formation of satiety, was analyzed in HFD + obese + Zn group when compared to HFD + obese ones. Serum triglyceride concentration tended to decrease with the effect of Zn in obese rats. In conclusion, it can be said that oral use of Zn could improve energy balance and prevent the occurrence of metabolic diseases related to obesity depending on the anti-inflammatory effect of Zn.

Nesfatin-1 in lipid metabolism and lipid-related diseases

Nesfatin-1, an anorexic neuropeptide discovered in 2006, is widely distributed in the central nervous system and peripheral tissues. It has been shown to be involved in the regulation of food intake and lipid metabolism, inhibiting fat accumulation, accelerating lipid decomposition, and in general, inhibiting the development of lipid-related diseases, such as obesity and metabolic syndrome. Potential mechanisms of Nesfatin-1 action in lipid metabolism and lipid-related diseases will be discussed as well as its role as a biomarker in cardiovascular disease. This review expected to provide a new strategy for the diagnosis and prevention of clinically related diseases.

SFPQ associated with a co-activator for PPARγ, HELZ2, regulates key nuclear factors for adipocyte differentiation

We recently isolated a novel co-activator of peroxisome proliferator-activated receptor γ, helicase with zinc finger 2 (HELZ2). HELZ2 null mice were resistant to diet-induced obesity and NAFFL/NASH, and HELZ2 was phosphorylated at tyrosine residues. In order to find a factor related to HELZ2, we analyzed products co-immunoprecipitated with phosphorylated HELZ2 by mass spectrometry analyses. We identified proline- and glutamine-rich (SFPQ) as a protein associating with tyrosine-phosphorylated HELZ2. The knockdown of SFPQ in 3T3-L1 cells downregulated mRNA levels of transcription factors including Krox20, Cebpβ, and Cebpδ: key factors for early-stage adipocyte differentiation. In addition, knockdown of SFPQ inhibited 3T3-L1 cell differentiation to mature adipocytes. These findings demonstrated that SFPQ associating with HELZ2 is an important novel transcriptional regulator of adipocyte differentiation.

Central nesfatin-1 activates lipid mobilization in adipose tissue and fatty acid oxidation in muscle via the sympathetic nervous system

Little is known about the influence of central nesfatin-1 on lipid metabolism under diabetic conditions. The main objective of this study was to characterize the mechanisms by which central nesfatin-1 regulates lipid metabolism in streptozotocin (STZ)-induced type 2 diabetes mellitus (T2DM) and whether the sympathetic nervous system is involved. Male Kunming mice were fed high-fat diets (HFDs) and were treated twice with low-dose STZ (100 mg/kg, intraperitoneal [IP]) to generate the T2DM model. Pharmacological adrenergic blockage (phentolamine 10 mg/kg, propranolol 0.017 mmol) and surgical denervation of sympathetic nervous system of the hindlimb and inguinal fat were used to block nerve conduction to determine whether the effect of central nesfatin-1 required the hypothalamic-sympathetic nervous system axis. Plasma free fatty acid (FFA) and insulin levels were measured. AMP-activated protein kinase (AMPK) levels in skeletal muscle and hormone-sensitive lipase and adipose triglycerides lipase (HSL/ATGL) levels in white adipose tissue (WAT) were measured using western blot. mRNA expression of AMPK was measured. We found that there were significantly fewer NUCB2/nesfatin-1 immunoreactive neurons in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) in T2DM mice. Central nesfatin-1 administration decreased levels of plasma FFA significantly and activated AMPK to enhance fatty-acid oxidation in skeletal muscle in T2DM mice. In addition, HSL and ATGL were significantly activated during triglyceride mobilization in WAT triggered by central nesfatin-1 administration. Adrenergic blockade and morphological denervation of the sciatic and femoral nerves reduced these changes. Taken together, these data suggest that central nesfatin-1 regulates peripheral lipid metabolism in type 2 diabetes via the sympathetic nervous system.

Examination and characterisation of burst spinal cord stimulation on cerebrospinal fluid cellular and protein constituents in patient responders with chronic neuropathic pain - A Pilot Study

INTRODUCTION

Patients with neuropathic pain have altered proteomic and neuropeptide constituents in cerebrospinal fluid (CSF) compared to controls. Tonic spinal cord stimulation (SCS) has demonstrated differential expression of neuropeptides in CSF before and after treatment suggesting potential mechanisms of action. Burst-SCS is an evidence-based paraesthesia free waveform utilised for neuropathic pain with a potentially different mechanistic action to tonic SCS. This study examines the dynamic biological changes of CSF at a cellular and proteome level after Burst-SCS.

METHODS

Patients with neuropathic pain selected for SCS had CSF sampled prior to implant of SCS and following 8 weeks of continuous Burst-SCS. Baseline and 8-week pain scores with demographics were recorded. T cell frequencies were analysed by flow cytometry, proteome analysis was performed using mass spectrometry and secreted cytokines, chemokines and neurotrophins were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

4 patients (2 females, 2 males) with a mean age of 51 years (+/-SEM 2.74, SD 5.48) achieved a reduction in pain of >50% following 8 weeks of Burst-SCS. Analysis of the CSF proteome indicated a significant alteration in protein expression most related to synapse assembly and immune regulators. There was significantly lower expression of the proteins: growth hormone A1 (PRL), somatostatin (SST), nucleobindin-2 (NUCB2), Calbindin (CALB1), acyl-CoA binding protein (DBI), proSAAS (PCSK1N), endothelin-3 (END3) and cholecystokinin (CCK) after Burst-SCS. The concentrations of secreted chemokines and cytokines and the frequencies of T cells were not significantly changed following Burst-SCS.

CONCLUSION

This study characterised the alteration in the CSF proteome in response to burst SCS in vivo. Functional analysis indicated that the alterations in the CSF proteome is predominately linked to synapse assembly and immune effectors. Individual protein analysis also suggests potential supraspinal mechanisms.

Clitoria ternatea Flower Petal Extract Inhibits Adipogenesis and Lipid Accumulation in 3T3-L1 Preadipocytes by Downregulating Adipogenic Gene Expression

Clitoria ternatea (commonly known as blue pea) flower petal extract (CTE) is used as a natural colorant in a variety of foods and beverages. The objective of study was to determine the inhibitory effect of CTE on adipogenesis in 3T3-L1 preadipocytes. The phytochemical profiles of CTE were analyzed by liquid chromatography and tandem mass spectrometry (LC-MS/MS). Anti-adipogenesis effect of CTE was measured by using Oil Red O staining, intracellular triglyceride assay, quantitative real-time PCR and western blot analysis in 3T3-L1 adipocytes. Cell cycle studies were performed by flow cytometry. Lipolysis experiments were performed using a colorimetric assay kit. In early stages, CTE demonstrated anti-adipogenic effects through inhibition of proliferation and cell cycle retardation by suppressing expression of phospho-Akt and phospho-ERK1/2 signaling pathway. The results also showed that CTE inhibited the late stage of differentiation through diminishing expression of adipogenic transcription factors including PPARγ and C/EBPα. The inhibitory action was subsequently attenuated in downregulation of fatty acid synthase and acetyl-CoA carboxylase, causing the reduction of TG accumulation. In addition, CTE also enhanced catecholamine-induced lipolysis in adipocytes. These results suggest that CTE effectively attenuates adipogenesis by controlling cell cycle progression and downregulating adipogenic gene expression.

Insulinotropic nucleobindin-2/nesfatin-1 is dynamically expressed in the haemochorial mouse and human placenta

The placenta is the physiological bridge between mother and fetus and has life-sustaining functions during pregnancy, including metabolic regulation, fetal protection and hormone secretion. Nucleobindin-2 (NUCB2) is a calcium- and DNA-binding protein and precursor of nesfatin-1, a signalling peptide with multiple functions, including regulation of energy homeostasis and glucose transport. These are also key functions of the placenta, yet NUCB2/nesfatin-1 expression has never been comprehensively studied in this organ. In the present study, mouse placental samples from Embryonic Day (E) 7.5 to E17.5 and human chorionic villi from the first and second trimester, as well as term pregnancy, were analysed for NUCB2/nesfatin-1 expression by immunohistochemistry with an antiserum that recognised both NUCB2 and nesfatin-1. From E7.5 to E9.5, NUCB2/nesfatin-1 was expressed in the ectoplacental cone, then parietal trophoblast giant cells and early spongiotrophoblast. At E10.5–12.5, NUCB2/nesfatin-1 expression became detectable in the developing labyrinth. From E12.5 and onwards, NUCB2/nesfatin-1 was expressed in the glycogen trophoblast cells, as well as highly expressed in syncytiotrophoblast, sinusoidal trophoblast giant cells and fetal capillary endothelial cells of the labyrinth. In all trimesters of human pregnancy, NUCB2/nesfatin-1 was highly expressed in syncytiotrophoblast. In addition, there was a significant increase in NUCB2 expression in human primary trophoblast cells induced to syncytialise. Thus, the haemochorial mammalian placenta is a novel source of NUCB2/nesfatin-1 and likely a site of its action, with potential roles in glucose homeostasis and/or nutrient sensing.

DNA methylation in silkworm genome may provide insights into epigenetic regulation of response to Bombyx mori cypovirus infection

DNA methylation is an important epigenetic modification that regulates a wide range of biological processes including immune response. However, information on the epigenetics-mediated immune mechanisms in insects is limited. Therefore, in this study, we examined transcriptomes and DNA methylomes in the fat body and midgut tissues of silkworm, Bombyx mori with or without B. mori cytoplasmic polyhedrosis virus (BmCPV) infection. The transcriptional profile and the genomic DNA methylation patterns in the midgut and fat body were tissue-specific and dynamically altered after BmCPV challenge. KEGG pathway analysis revealed that differentially methylated genes (DMGs) could be involved in pathways of RNA transport, RNA degradation, nucleotide excision repair, DNA replication, etc. 27 genes were shown to have both differential expression and differential methylation in the midgut and fat body of infected larvae, respectively, indicating that the BmCPV infection-induced expression changes of these genes could be mediated by variations in DNA methylation. BS-PCR validated the hypomethylation of G2/M phase-specific E3 ubiquitin-protein ligase-like gene in the BmCPV infected midgut. These results demonstrated that epigenetic regulation may play roles in host-virus interaction in silkworm and would be potential value for further studies on mechanism of BmCPV epithelial-specific infection and epigenetic regulation in the silkworm.

Nesfatin-1: a new energy-regulating peptide with pleiotropic functions. Implications at cardiovascular level

Nesfatin-1 is a new energy-regulating peptide widely expressed at both central and peripheral tissues with pleiotropic effects. In the last years, the study of nesfatin-1 actions and its possible implication in the development of different diseases has created a great interest among the scientific community. In this review, we will summarize nesfatin-1 main functions, focusing on its cardiovascular implications.

Nucleobindin 2 (NUCB2) in human endometrial carcinoma: a potent prognostic factor associated with cell proliferation and migration

Nucleobindin 2 (NUCB2) is a multifunctional protein containing several functional domains, and associated with wide variety of biological process such as food intake and energy homeostasis. Recently, NUCB2 has been implicated in not only normal human tissues but also some kinds of human malignancies. However, its clinical and/or biological significance has largely remained unknown in endometrial carcinomas. We therefore immunolocalized NUCB2 protein in 87 endometrial carcinoma tissues and examined its clinical significance. NUCB2 immunoreactivity was detected in 19 out of 87 (22%) of endometrial carcinoma cases examined, and positively correlated with Ki67 labeling index, while there was no significant correlation between NUCB2 and stage, histological grade, and progesterone receptor status. Furthermore, NUCB2 immunoreactivity was significantly correlated with increased risk of recurrence and worse clinical outcome regardless of stage or histological grade. Subsequent multivariate analyses did reveal that NUCB2 immunoreactivity was an independent prognostic factor for both disease-free survival and endometrial cancer specific survival. In vitro experiments demonstrated that knockdown of NUCB2 using specific siRNA for NUCB2 significantly impaired cell proliferation and migration of the endometrial carcinoma cell lines, Ishikawa and Sawano cells, and that nesfatin-1 treatment significantly promoted cell proliferation and migration in Ishikawa cells. These findings possibly suggested that NUCB2 and/or nesfatin-1 had pivotal roles in the progression of endometrial carcinomas. Immunohistochemical NUCB2 status may therefore serve as a potent biomarker for endometrial carcinomas.

AMPK-dependent modulation of hepatic lipid metabolism by nesfatin-1

The aim of this study was to characterize the mechanism by which peripheral nesfatin-1 regulates hepatic lipid metabolism. Continuous peripheral infusion of nesfatin-1 reduced adiposity and plasma levels of triglyceride and cholesterol. In mice fed high fat diet, peripheral nesfatin-1 significantly decreased hepatic steatosis measured by triglyceride content and oil red staining area and diameter. These alterations were associated with a significant reduction in lipogenesis-related transcriptional factors PPARγ and SREBP1, as well as rate-limited enzyme genes such as acaca, fasn, gpam, dgat1 and dgat2. In primary hepatocytes, nesfatin-1 inhibited both basal and oleic acid stimulated triglyceride accumulation, which was accompanied by a decrement in lipogenesis-related genes and an increase in β-oxidation-related genes. In cultured hepatocytes, nesfatin-1 increased levels of AMPK phosphorylation. Inhibition of AMPK by compound C blocked the reduction of triglyceride content elicited by nesfatin-1. Our studies demonstrate that nesfatin-1 attenuates lipid accumulation in hepatocytes by an AMPK-dependent mechanism.

Hypothalamic Nesfatin-1 Stimulates Sympathetic Nerve Activity via Hypothalamic ERK Signaling

Nesfatin-1 acts on the hypothalamus and regulates the autonomic nervous system. However, the hypothalamic mechanisms of nesfatin-1 on the autonomic nervous system are not well understood. In this study, we found that intracerebroventricular (ICV) administration of nesfatin-1 increased the extracellular signal-regulated kinase (ERK) activity in rats. Furthermore, the activity of sympathetic nerves, in the kidneys, liver, and white adipose tissue (WAT), and blood pressure was stimulated by the ICV injection of nesfatin-1, and these effects were abolished owing to pharmacological inhibition of ERK. Renal sympathoexcitatory and hypertensive effects were also observed with nesfatin-1 microinjection into the paraventricular hypothalamic nucleus (PVN). Moreover, nesfatin-1 increased the number of phospho (p)-ERK1/2-positive neurons in the PVN and coexpression of the protein in neurons expressing corticotropin-releasing hormone (CRH). Pharmacological blockade of CRH signaling inhibited renal sympathetic and hypertensive responses to nesfatin-1. Finally, sympathetic stimulation of WAT and increased p-ERK1/2 levels in response to nesfatin-1 were preserved in obese animals such as rats that were fed a high-fat diet and leptin receptor-deficient Zucker fatty rats. These findings indicate that nesfatin-1 regulates the autonomic nervous system through ERK signaling in PVN-CRH neurons to maintain cardiovascular function and that the antiobesity effect of nesfatin-1 is mediated by hypothalamic ERK-dependent sympathoexcitation in obese animals.

Compensatory Islet Response to Insulin Resistance Revealed by Quantitative Proteomics

Compensatory islet response is a distinct feature of the prediabetic insulin-resistant state in humans and rodents. To identify alterations in the islet proteome that characterize the adaptive response, we analyzed islets from 5 month old male control, high-fat diet fed (HFD), or obese ob/ob mice by LC-MS/MS and quantified ~1100 islet proteins (at least two peptides) with a false discovery rate < 1%. Significant alterations in abundance were observed for ~350 proteins among groups. The majority of alterations were common to both models, and the changes of a subset of ~40 proteins and 12 proteins were verified by targeted quantification using selected reaction monitoring and western blots, respectively. The insulin-resistant islets in both groups exhibited reduced expression of proteins controlling energy metabolism, oxidative phosphorylation, hormone processing, and secretory pathways. Conversely, an increased expression of molecules involved in protein synthesis and folding suggested effects in endoplasmic reticulum stress response, cell survival, and proliferation in both insulin-resistant models. In summary, we report a unique comparison of the islet proteome that is focused on the compensatory response in two insulin-resistant rodent models that are not overtly diabetic. These data provide a valuable resource of candidate proteins to the scientific community to undertake further studies aimed at enhancing β-cell mass in patients with diabetes. The data are available via the MassIVE repository, under accession no. MSV000079093.

Nesfatin-1 as a new potent regulator in reproductive system

Nesfatin-1 is a recently discovered anorexigenic peptide which is distributed in several brain areas implicated in the feeding and metabolic regulation. Recently, it has been reported that nesfatin-1 is expressed not only in brain, but also in peripheral organs such as digestive organs, adipose tissues, heart, and reproductive organs. Nesfatin-1 is markedly expressed in the pancreas, stomach and duodenum. Eventually, the nesfatin-1 expression in the digestive organs may be regulated by nutritional status, which suggests a regulatory role of peripheral nesfatin-1 in energy homeostasis. Nesfatin-1 is also detected in the adipose tissues of humans and rodents, indicating that nesfatin-1 expression in the fat may regulate food intake independently, rather than relying on leptin. In addition, nesfatin-1 is expressed in the heart as a cardiac peptide. It suggests that nesfatin-1 may regulate cardiac function and encourage clinical potential in the presence of nutrition-dependent physio-pathologic cardiovascular diseases. Currently, only a few studies demonstrate that nesfatin-1 is expressed in the reproductive system. However, it is not clear yet what function of nesfatin-1 is in the reproductive organs. Here, we summarize the expression of nesfatin-1 and its roles in brain and peripheral organs and discuss the possible roles of nesfatin-1 expressed in reproductive organs, including testis, epididymis, ovary, and uterus. We come to the conclusion that nesfatin-1 as a local regulator in male and female reproductive organs may regulate the steroidogenesis in the testis and ovary and the physiological activity in epididymis and uterus.

Effect of dapagliflozin on colon cancer cell [Rapid Communication]

Dapagliflozin is a SGLT2 (Sodium/Glucose cotransporter 2) inhibitor that reduces circulating glucose levels in type 2 diabetic patients by blocking the SGLT2-dependent reabsorption of glucose in the kidney. Dapagliflozin is metabolized by UGT1A9 (UDP Glucuronosyltransferase 1 family, Polypeptidase A9), suppressing its SGLT2 inhibitor activity. However little information is available on whether dapagliflozin acts in the absence of dapagliflozin metabolism. Treatment with 0.5μM dapagliflozin significantly reduced the number of HCT116 cells, which express SGLT2 but not UGT1A9. This was independent of SGLT2 inhibition, as the SGLT2 inhibitor phlorizin had no effect. Dapagliflozin also enhanced Erk phosphorylation but without changing levels of uncleaved and cleaved PPAR and uncleaved caspase-3, suggesting that the cause of the decrease in HCT116 cell number was apoptosis independent cell death. Taken together, these data indicate a new potential role for dapagliflozin as an anticancer reagent in tumor cell populations that do not express UGT1A9.

Decreased serum nesfatin-1 levels in endometriosis

OBJECTIVE(S)

To investigate serum nesfatin-1 levels in endometriosis patients.

STUDY DESIGN

Twenty-five women who were laparoscopically and histopathologically diagnosed with endometriosis (endometriosis group) and 25 women without any pelvic pathology detected by laparoscopy (control group) were enrolled in the study. Serum nesfatin-1 levels were compared between the two groups before and after adjustment for body mass index (BMI) and age.

RESULTS

Patients in the endometriosis group had lower BMI than those in the control group (22.3 ± 4.8 kg/m(2) vs. 25.8 ± 4.2 kg/m(2), p=0.009). There was no statistically significant correlation between BMI and serum nesfatin-1 levels (p=0.870). Serum nesfatin-1 level was statistically significantly lower in the endometriosis group than in the control group (7.2 ± 1.3 pg/ml vs. 10.6 ± 2.8 pg/ml, p=0.0001). This result did not change after the adjustment for BMI and age.

CONCLUSION(S)

Serum levels of nesfatin-1 are decreased in endometriosis patients but its exact role in the etiopathogenesis of endometriosis remains to be clarified.

THRAP3 interacts with HELZ2 and plays a novel role in adipocyte differentiation

Using yeast two-hybrid screen, we previously isolated HELZ2 (helicase with zinc finger 2, transcriptional coactivator) that functions as a coregulator of peroxisome proliferator-activated receptorγ (PPARγ). To further delineate its molecular function, we here identified thyroid hormone receptor-associated protein3 (THRAP3), a putative component of the Mediator complex, as a protein stably associating with HELZ2 using immunoprecipitation coupled with mass spectrometry analyses. In immunoprecipitation assays, Thrap3 could associate with endogenous Helz2 as well as Pparg in differentiated 3T3-L1 cells. HELZ2 interacts with the serine/arginine-rich domain and Bcl2 associated transcription factor1-homologous region in THRAP3, whereas THRAP3 directly binds 2 helicase motifs in HELZ2. HELZ2 and THRAP3 synergistically augment transcriptional activation mediated by PPARγ, whereas knockdown of endogenous THRAP3 abolished the enhancement by HELZ2 in reporter assays. Thrap3, similar to Helz2, is evenly expressed in the process of adipogenic differentiation in 3T3-L1 cells. Knockdown of Thrap3 in 3T3-L1 preadipocytes using short-interfering RNA did not influence the expression of Krox20, Klf5, Cebpb, or Cebpd during early stages of adipocyte differentiation, but significantly attenuated the expression of Pparg, Cebpa, and Fabp4/aP2 and accumulation of lipid droplets. Pharmacologic activation of Pparg by troglitazone could not fully restore the differentiation of Thrap3-knockdown adipocytes. In chromatin immunoprecipitation assays, endogenous Helz2 and Thrap3 could be co-recruited, in a ligand-dependent manner, to the PPARγ-response elements in Fabp4/aP2 and Adipoq gene enhancers in differentiated 3T3-L1 cells. These findings collectively suggest that Thrap3 could play indispensable roles in terminal differentiation of adipocytes by enhancing PPARγ-mediated gene activation cooperatively with Helz2.

Recent progress in research on the distribution and function of NUCB2/nesfatin-1 in peripheral tissues

Nesfatin-1 is a polypeptide derived from the posttranslational processing of the N-terminal fragment of nucleobindin 2 (NUCB2), that was originally identified as an anorexigenic hypothalamic neuropeptide. A number of reports have recently shown that NUCB2/nesfatin-1 is widely expressed in various peripheral tissues, including those of the gastrointestinal tract where it may participate in various pathophysiological processes. One of its roles may be regulation of energy homeostasis. As a result, nesfatin-1 may be a novel target for exploring the underlying mechanisms and the treatment of metabolic syndromes.