Association of tuberculosis risk with genetic polymorphisms of the immune checkpoint genes PDCD1, CTLA-4, and TIM3.

The immune checkpoint proteins were reported to involve to host resistance to Mycobacteria tuberculosis (Mtb). Here, we evaluated 11 single nucleotide polymorphisms (SNPs) in PDCD1, CTLA4, and HAVCR2 genes between participants with and without TB infection. Genomic DNA isolated from 285 patients with TB and 270 controls without TB infection were used to perform the genotyping assay. Odds ratios were used to characterize the association of 11 SNPs with TB risk. In this study, the various genotypes of the 11 SNPs did not differ significantly in frequency between the non-TB and TB groups. When patients were stratified by sex, however, men differed significantly from women in genotype frequencies at HAVCR2 rs13170556. Odds ratios indicated that rs2227982, rs13170556, rs231775, and rs231779 were sex-specifically associated with TB risk. In addition, the combinations of rs2227982/rs13170556 GA/TC in men and the A-C-C haplotype of rs231775-rs231777-rs231779 in women were significantly associated with TB risk. Our results indicate that rs2227982 in PDCD1 and rs13170556 in HAVCR2 are associated with increased TB susceptibility in men and that the CTLA4 haplotype appears protective against TB in women.

Resistin stimulates PC-3 prostate cancer cell growth through stimulation of SOCS3 and SOCS5 genes.

Resistin and suppressors of cytokine signaling (SOCSs) have been reported to regulate prostate cancer (PCa) cell proliferation and survival, respectively. Whether any of the SOCS molecules mediate the mitogenic effect of resistin on PCa cells is unknown. Using PC-3 human PCa cells, we found that resistin upregulates the expression of SOCS3 and SOCS5 mRNA, but not SOCS7 mRNA, in a dose- and time-dependent manner. The resistin-induced increases in SOCS3 and SOCS5 expression and cell proliferation were prevented by pretreatment with specific inhibitors of the TLR4, ERK, p38 MAPK, JNK, PI3K, and JAK2 proteins. However, pretreatment with a TLR2 inhibitor had no effect on resistin-mediated SOCS3 and SOCS5 expression. In addition, the effects of resistin on SOCS3, SOCS5, and SOCS7 mRNA levels were cell type-specific. Overexpression of either SOCS3 or SOCS5 enhanced further resistin-stimulated growth of PC-3 cells, whereas silencing SOCS3 or SOCS5 antagonized resistin-increased cell growth. Further PCa tissue analysis demonstrated higher levels of RETN, TLR4, SOCS3, and SOCS5 mRNAs in cancer tissues than benign prostate hyperplasia and indicated positive correlations among RETN, TLR4, and SOCS5. These data suggest that SOCS5, TLR4, and, to a lesser extent, SOCS3 can mediate the mitogenic effect of resistin on PC-3 PCa cells.

A Wireless Soil pH and Conductance Monitoring Chip Powered by Soil Microbial and Photovoltaic Energy Cells.

This paper presents an energy-autonomous wireless soil pH and electrical conductance measurement IC powered by soil microbial and photovoltaic energy. The chip integrates highly efficient dual-input, dual-output power management units, sensor readout circuits, a wireless receiver, and a transmitter. The design scavenges ambient energy with a maximal power point tracking mechanism while achieving a peak efficiency of 81.3% and the efficiency is more than 50% over the 0.05-14 mW load range. The sensor readout IC achieves a sensitivity of -8.8 kHz/pH and 6 kHz·m/S, a noise floor of 0.92 x 10-3 pH value, and 1.4 mS/m conductance. To avoid interference, a 433 MHz transceiver incorporates chirp modulation and on-off keying (OOK) modulation for data uplink and downlink communication. The receiver sensitivity is -80 dBm, and the output transmission power is -4 dBm. The uplink data rate is 100 kb/s using burst chirp modulation and gated Class E PA, while the downlink data rate is 10 kb/s with a self-frequency tracking mixer-first receiver.

Relationship between gut microbiota and lung function decline in patients with chronic obstructive pulmonary disease: a 1-year follow-up study.

OBJECTIVE: Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease characterized by a persistent limitation in airflow. Gut microbiota is closely correlated with lung inflammation. However, gut microbiota has not been studied in patients with declining lung function, due to chronic lung disease progression. SUBJECTS AND METHODS: Stool samples were obtained from 55 patients with COPD that were in stable condition at enrolment (stage 1) and at a 1-year follow-up (stage 2). After extracting stool DNA, we performed next generation sequencing to analyse the distribution of gut microbiota. RESULTS: Patients were divided to control and declining lung function groups, based on whether the rate of forced expiratory volume in 1 s (FEV1) had declined over time. An alpha diversity analysis of initial and follow-up stool samples showed a significant difference in the community richness of microbiota in the declining function group, but not in the control group. At the phylum level, Bacteroidetes was more abundant in the control group and Firmicutes was more abundant in the declining function group. The Alloprevotella genus was more abundant in the control group than in the declining function group. At 1-year follow-up, the mean proportions of Acinetobacter and Stenotrophomonas significantly increased in the control and declining function groups, respectively. CONCLUSION: Some community shifts in gut microbiota were associated with lung function decline in COPD patients under regular treatment. Future studies should investigate the mechanism underlying alterations in lung function, due to changes in gut bacterial communities, in COPD.

Comprehensive profiling of the gut microbiota in patients with chronic obstructive pulmonary disease of varying severity.

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease that reduces lung and respiratory function, with a high mortality rate. Severe and acute deterioration of COPD can easily lead to respiratory failure, resulting in personal, social, and medical burden. Recent studies have shown a high correlation between the gut microbiota and lung inflammation. In this study, we investigated the relationship between gut microbiota and COPD severity. A total of 60 COPD patients with varying severity according to GOLD guidelines were enrolled in this study. DNA was extracted from patients' stool and 16S rRNA data analysis conducted using high-throughput sequencing followed by bioinformatics analysis. The richness of the gut microbiota was not associated with COPD severity. The gut microbiome is more similar in stage 1 and 2 COPD than stage 3+4 COPD. Fusobacterium and Aerococcus were more abundant in stage 3+4 COPD. Ruminococcaceae NK4A214 group and Lachnoclostridium were less abundant in stage 2-4, and Tyzzerella 4 and Dialister were less abundant in stage 1. However, the abundance of a Bacteroides was associated with blood eosinophils and lung function. This study suggests that no distinctive gut microbiota pattern is associated with the severity of COPD. The gut microbiome could affect COPD by gut inflammation shaping the host immune system.

Impact of Annual Exposure to Polycyclic Aromatic Hydrocarbons on Acute Exacerbation Frequency in Asthmatic Patients.

PURPOSE: Exposure to polycyclic aromatic hydrocarbons (PAHs) associated with ambient air particulate matter (PM) poses significant health concerns. Increased acute exacerbation (AE) frequency in asthmatic patients has been associated with ambient PAHs, but which subgroup of patients are particularly susceptible to ambient PAHs is uncertain. We developed a new model to simulate grid-scale PM2.5-PAH levels in order to evaluate whether the severity of asthma as measured by the Global Initiative of Asthma (GINA) levels of treatment is related to cumulative exposure of ambient PAHs. METHODS: Patients with asthma residing in the northern Taiwan were reviewed retrospectively from 2014 to 2017. PM2.5 were sampled and analysed for PAHs twice a month over a 72-hour period, in addition to collecting the routinely monitored air pollutant data from an established air quality monitoring network. In combination with correlation analysis and principal component analysis, multivariate linear regression models were performed to simulate hourly grid-scale PM2.5-PAH concentrations (ng/m3). A geographic information system mapping approach with ordinary kriging interpolation method was used to calculate the annual exposure of PAHs (ng/m). RESULTS: Among the 387 patients with asthma aged 18 to 93 (median 62), 97 subjects were treated as GINA step 5 (24%). Asthmatics in GINA 5 subgroup with high annual PAHs exposure were likely to have a higher annual frequency of any AE (1 (0-12), p<0.0001). Annual PAHs exposure was correlated with the annual frequency of any exacerbation (r=0.11, p=0.02). This was more significant in the GINA 5 subgroup (r=0.29, p=0.005) and in the GINA 5 subgroup with severe acute exacerbations (r=0.51, p=0.002). Annual PAHs exposure, severe acute exacerbation and GINA steps were independent variables that predict annual frequency of any exacerbation. CONCLUSION: Asthmatic patients in the GINA 5 subgroup with acute exacerbations were more susceptible to the effect of environmental PAHs on their exacerbation frequency. Reducing environmental levels of PAHs will have the greatest impact on the more severe asthma patients.

Particulate matters increase epithelial-mesenchymal transition and lung fibrosis through the ETS-1/NF-κB-dependent pathway in lung epithelial cells.

BACKGROUND: Particulate matters (PMs) in ambient air pollution are closely related to the incidence of respiratory diseases and decreased lung function. Our previous report demonstrated that PMs-induced oxidative stress increased the expression of proinflammatory intracellular adhesion molecule-1 (ICAM-1) through the IL-6/AKT/STAT3/NF-κB pathway in A549 cells. However, the role of O-PMs in epithelial-mesenchymal transition (EMT) development and pulmonary fibrosis and the related mechanisms have not been determined. The aim of this study was to investigate the effects of O-PMs on the pathogenesis of EMT and pulmonary fibrosis as well as the expression of ETS-1 and NF-κB p65, in vitro and in vivo. RESULTS: O-PMs treatment induced EMT development, fibronectin expression, and cell migration. O-PMs affected the expression of the EMT-related transcription factors NF-κB p65 and ETS-1. Interference with NF-κB p65 significantly decreased O-PMs-induced fibronectin expression. In addition, O-PMs affected the expression of fibronectin, E-cadherin, and vimentin through modulating ETS-1 expression. ATN-161, an antagonist of integrin α5ß1, decreased the expression of fibronectin and ETS-1 and EMT development. EMT development and the expression of fibronectin and ETS-1 were increased in the lung tissue of mice after exposure to PMs for 7 and 14 days. There was a significant correlation between fibronectin and ETS-1 expression in human pulmonary fibrosis tissue. CONCLUSION: O-PMs can induce EMT and fibronectin expression through the activation of transcription factors ETS-1 and NF-κB in A549 cells. PMs can induce EMT development and the expression of fibronectin and ETS-1 in mouse lung tissues. These findings suggest that the ETS-1 pathway could be a novel and alternative mechanism for EMT development and pulmonary fibrosis.

The association of inflammasome and TLR2 gene polymorphisms with susceptibility to tuberculosis in the Han Taiwanese population.

Pulmonary tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) is a global public health concern. Although inflammasome and the toll-like receptor 2 (TLR2) genes play an important role in host defense against Mtb, the associations of polymorphisms in these genes with TB risk are incompletely understood. A total of 230 TB patients and 213 individuals without TB were enrolled in this study. A significant difference in the frequencies of different AIM2 rs2276405 genotypes between the non-TB and TB groups was detected. When the patients were stratified by gender or age, significant differences in genotype frequencies at NLRP3 rs34298354 in men and in non-aged (≤65-year-old) subjects and at IFI16 rs1772408 in women were found. OR analysis showed that the TC rs34298354 genotype in NLRP3 was associated with reduced risk of TB. In women, the AG rs1772408 genotype in IFI16 was associated with decreased TB risk. Haplotype analysis showed that, in comparison with the most common haplotype (T-T) of rs3804099-rs3804100 in the TLR2 gene, the C-T haplotype was associated with an increased risk for TB. Our study indicates that rs34298354 in NLRP3 and rs1772408 in IFI16 protect individuals from TB, and that the less common TLR2 haplotype is associated with increased TB susceptibility.

Polymorphisms of suppressor of cytokine signaling-3 associated with susceptibility to tuberculosis among Han Taiwanese.

BACKGROUND: Suppressors of cytokine signaling (SOCS), particularly SOCS-3, allow discrimination of patients with active tuberculosis (TB) from healthy subjects in a gender- and age-dependent manner. However, no information is available on whether single nucleotide polymorphisms (SNPs) in the SOCS-3 gene occur in patients with TB. This study was designed to investigate SOCS-3 SNPs in association with susceptibility to TB in the Taiwanese population. METHODS: Four SNPs in the SOCS-3 gene located at rs8064821, rs4969168, rs2280148, and rs35037722 were studied by the TaqMan SNP Genotyping assay in 200 healthy and 210 TB patients enrolled in 2015-2018. RESULTS: Significant differences were not detected in genotype frequencies or odds ratios (ORs) between healthy and TB patients for any of the four polymorphisms. The lack of significant differences was also found when the patients were stratified by sex. However, males exhibited GG homozygous at rs35037722 in association with susceptibility to TB after the OR analysis was adjusted for age. For rs8064821, AA and AC genotypes were associated with TB susceptibility in patients ≤ 65 years old compared to CC genotype, whereas older subjects had no such association. CONCLUSIONS: The results suggest that particular SOCS-3 SNPs are dependent on gender or age to influence TB susceptibility in the Han Taiwanese.

Whole-genome methylation profiling from PBMCs in acute-exacerbation COPD patients with good and poor responses to corticosteroid treatment.

Identifying heterogeneity in chronic obstructive pulmonary disease (COPD) phenotypes is important for the development of personalized medicine. Genome-wide analysis was used to compare the methylation levels of peripheral blood mononuclear cell (PBMC) samples from 24 acute-exacerbation (AE) COPD patients with good/poor response to corticosteroid therapy and 12 non-COPD controls. Pyrosequencing was employed to validate the genome-wide analysis. In the dataset specific to COPD patients with a good response, enrichment was identified for the following: genes in the Ubl conjugation pathway, nicotinamide nucleotide metabolism, the alkaloid metabolic process, and regulation of the glucose metabolic process. Validation results confirmed CpG sites in PRKAG2 with different methylation levels in COPD patients and normal subjects. The CpG sites of ALOX5AP were specifically associated with a good response. The results suggested that a good response to corticosteroid treatment for AE-COPD should be considered a distinct subtype according to the putative epigenetic mechanism.

Amorphous Phosphorus-Doped Cobalt Sulfide Modified on Silicon Pyramids for Efficient Solar Water Reduction.

Cobalt sulfide (CoS x) functioned as a co-catalyst to accelerate the kinetics of photogenerated electrons on Si photocathode, leading to the enhancement of solar hydrogen evolution efficiency. By doping phosphorus heteroatoms, CoS x materials showed an improved catalytic activity because of superior surface area and quantity of active sites. Furthermore, increased vacancies in unoccupied electronic states were observed, as more phosphorus atoms doped into CoS x co-catalysts. Although these vacant sites improved the capability to accept photoinduced electrons from Si photoabsorber, chemisorption energy of atomic hydrogen on catalysts was the dominant factor affecting in photoelectrochemical performance. We suggested that P-doped CoS x with appropriate doping quantities showed thermoneutral hydrogen adsorption. Excess phosphorus dopants in CoS x contributed to excessively strong adsorption with H atoms, causing the poor consecutive desorption ability of photocatalytic reaction. The optimal P-doped CoS x-decorated Si photocathode showed a photocurrent of -20.6 mA cm-2 at 0 V. Moreover, a TiO2 thin film was deposited on the Si photocathode as a passivation layer for improving the durability. The current density of 10 nm TiO2-modified photocathode remained at approximately -13.3 mA cm-2 after 1 h of chronoamperometry.

Suppressors of cytokine signaling in tuberculosis.

Tuberculosis (TB), a global disease mainly infected by Mycobacterium tuberculosis, remains leading public health problem worldwide. Suppressors of cytokine signaling (SOCSs) play important roles in the protection against microbial infection. However, the relationship between members of the SOCS family and tuberculosis infection remains unclear. Using peripheral blood mononuclear cells, we investigated the mRNA expression profiles of SOCS subfamilies among active TB, latent tuberculosis infection (LTBI), and healthy individuals. Our results showed that active tuberculosis subjects had higher levels of SOCS-3 mRNA, lower expressions of SOCS-2, -4, -5, -6, -7, and cytokine-inducible SH2-containing protein-1 (CIS-1) mRNAs, but not SOCS-1 mRNA than healthy and LTBI subjects. In men, LTBI patients had lower SOCS-3 than healthy subjects, and active TB patients had lower levels of SOCS-4, -5, and CIS-1 mRNAs but higher levels of SOCS-3 mRNA than healthy subjects. In women, LTBI patients had lower SOCS-3 mRNA level than healthy subjects, and active TB patients had lower CIS-1 mRNA level than healthy subjects. In non-aged adults (< 65 years old), TB patients had higher SOCS-3 mRNA and lower levels of SOCS-2, -4, -5, -6, -7, and CIS-1 mRNAs; whereas, aged TB patients (≥ 65 years old) had lower levels of SOCS-5 and CIS-1 mRNAs. These data suggest that particular SOCS members and their correlative relationships allow discrimination of active TB from healthy and LTBI subjects.

VDR and VDBP genes polymorphisms associated with susceptibility to tuberculosis in a Han Taiwanese population.

BACKGROUND: The active metabolite (1, 25-dihydroxycholecalciferol) of vitamin D (25-hydroxycholecalciferol) leads to the activation of macrophages and the deficiency of vitamin D seems to be involved in the risk of tuberculosis (TB). The effects of vitamin D are exerted by interaction with the vitamin D receptor (VDR) and vitamin D receptor binding protein (VDBP) may be influenced by polymorphisms in the VDR and VDBP genes. In this study, variation in the VDR and VDBP genes was investigated in a Taiwanese population with TB. METHODS: We typed four VDR polymorphisms of restriction endonuclease sites for ApaI, TaqI, BsmI, and FokI and three VDBP polymorphisms-Thr420Lys, Asp416Glu, and Cys299Cys-in 198 patients with TB and 170 healthy volunteers. RESULTS: VDR TaqI, VDR BsmI, and VDBP Asp416Glu were significantly associated with TB susceptibility. Odd ratios of risk genotypes of the above three polymorphisms were 2.16 (95% confidence interval 1.01, 4.65), 2.14 (95% confidence interval 1.06, 4.31), and 2.24 (95% confidence interval 1.04, 4.80), respectively. VDBP haplotype analysis showed Gc1f carriers associated to TB. CONCLUSION: The polymorphisms in the VDR and VDBP genes appeared to be responsible for host susceptibility to human TB in a Taiwanese population.

Effective peak alignment for mass spectrometry data analysis using two-phase clustering approach.

In recent years, mass spectrometry data analysis has become an important protein identification technique. The mass spectrometry technologies emerge as useful tools for biomarker discovery through studying protein profiles in various biological specimens. In mining mass spectrometry datasets, peak alignment is a critical issue among the preprocessing steps that affect the quality of analysis results. However, the existing peak alignment methods are sensitive to noise peaks across various mass spectrometry samples. In this paper, we proposed a novel algorithm named Two-Phase Clustering for peak Alignment (TPC-Align) to align mass spectrometry peaks across samples in the pre-processing phase. The TPC-Align algorithm sequentially considers the distribution of intensity values and the locations of mass-to-charge ratio values of peaks between samples. Moreover, TPC-Align algorithm can also report a list of significantly differential peaks between samples, which serve as the candidate biomarkers for further biological study. The proposed peak alignment method was compared to the current peak alignment approach based on one-dimension hierarchical clustering through experimental evaluations and the results show that TPC-Align outperforms the traditional method on the real dataset.

Green tea (-)-epigallocatechin gallate suppresses IGF-I and IGF-II stimulation of 3T3-L1 adipocyte glucose uptake via the glucose transporter 4, but not glucose transporter 1 pathway.

This study investigated the pathways involved in EGCG modulation of insulin-like growth factor (IGF)-stimulated glucose uptake in 3T3-L1 adipocytes. EGCG inhibited IGF-I and IGF-II stimulation of adipocyte glucose uptake with dose and time dependencies. EGCG at 20µM for 2h decreased IGF-I- and IGF-II-stimulated glucose uptake by 59% and 64%, respectively. Pretreatment of adipocytes with antibody against the EGCG receptor (also known as the 67-kDa laminin receptor; 67LR), prevented the effects of EGCG on IGF-increased glucose uptake, but pretreatment with normal rabbit immunoglobulin did not. This suggests that the 67LR mediates the anti-IGF effect of EGCG on adipocyte glucose uptake. Further analysis indicated EGCG, IGF-I, and IGF-II did not alter total levels of GLUT1 or GLUT4 protein. However, EGCG prevented the IGF-increased GLUT4 levels in the plasma membrane and blocked the IGF-decreased GLUT4 levels in low-density microsomes. Neither EGCG nor its combination with IGF altered GLUT1 protein levels in the plasma membrane and low-density microsomes. EGCG also suppressed the IGF-stimulated phosphorylation of IGF signaling molecules, PKCζ/λ, but not AKT and ERK1/2, proteins. This study suggests that EGCG suppresses IGF stimulation of 3T3-L1 adipocyte glucose uptake through inhibition of the GLUT4 translocation, but not through alterations of the GLUT1 pathway.

Endothelin-1 stimulates resistin gene expression.

Resistin and endothelin (ET)-1 have been reported to inhibit adipogenesis and regulate adipocyte insulin resistance, respectively. Although both hormones interact with each other, the exact signaling pathway of ET-1 to act on resistin gene expression is still unknown. Using 3T3-L1 adipocytes, we investigated the signaling pathways involved in ET-1-stimulated resistin gene expression. The up-regulation of resistin mRNA expression by ET-1 depends on concentration and timing. The concentration of ET-1 that increased resistin mRNA levels by 100%-250% was approximately 100 nM for a range of 0.25-12 hours of treatment. Treatment with actinomycin D blocked ET-1-increased resistin mRNA levels, suggesting that the effect of ET-1 requires new mRNA synthesis. Treatment with an inhibitor of the ET type-A receptor, such as N-[1-Formyl-N-[N-[(hexahydro-1H-azepin-1-yl)carbonyl]-L-leucyl]-D-tryptophyl]-D-tryptophan (BQ610), but not with the ET type-B receptor antagonist N-[(cis-2,6-Dimethyl-1-piperidinyl)carbonyl]-4-methyl-L-leucyl-1-(methoxycarbonyl)-D-tryptophyl-D-norleucine (BQ788), blocked ET-1, increased the levels of resistin mRNA, and phosphorylated levels of downstream signaling molecules, such as ERK1/2, c-Jun N-terminal kinases (JNKs), protein kinase B (AKT), and signal transducer and activator of transcription 3 (STAT3). Moreover, pretreatment of specific inhibitors of either ERK1/2 (1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio]butadiene [U0126] and 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one [PD98059], two inhibitors of MEK1), JNKs (SP600125), phosphatidylinositol 3-kinase/AKT (LY294002 and Wortmannin), or Janus kinase 2 (JAK2)/STAT3 ((E)-2-Cyano-3-(3,4-dihydrophenyl)-N-(phenylmethyl)-2-propenamide, AG490) prevented ET-1-increased levels of resistin mRNA and reduced the ET-1-stimulated phosphorylation of ERK1/2, JNKs, AKT, and STAT3, respectively. However, the p38 kinase antagonist 4-[5-(4-Fluorophenyl)-2-[4-(methylsulfonyl)phenyl]-1H-imidazol-4-yl]pyridine (SB203580) did not alter the effect of ET-1. These results imply that ET type-A receptor, ERK1/2, JNKs, AKT, and JAK2, but not ET type-B receptor or p38, are necessary for the ET-1 stimulation of resistin gene expression. In vivo observations that ET-1 increased resistin mRNA and protein levels in sc and epididymal adipose tissues support the in vitro findings.

The forkhead transcription factor FOXO1 stimulates the expression of the adipocyte resistin gene.

Resistin is known as an adipocyte-specific hormone that can cause insulin resistance and decrease adipocyte differentiation. It can be regulated by transcriptional factors, but the possible role of forkhead transcription factor FOXO1 in regulating resistin gene expression is still unknown. Using 3T3 fibroblast and C3H10T1/2 and 3T3-L1 adipocytes, we found that transient overexpression of a non-phosphorylatable, constitutively active FOXO1, but not the wild type of FOXO1 or a DNA binding-deficient FOXO1, activated resistin promoter-directed luciferase expression. However, transient overexpression of a dominant-negative FOXO1 inactivated resistin promoter activity and reduced resistin mRNA expression. These observations indicate that the action of FOXO1 on resistin gene expression requires the activation of FOXO1 and that the effect of FOXO1 depends on the phosphorylation and dephosphorylation of FOXO1. The FOXO1 protein target sites on the resistin promoter were localized to the proximal -3545 to -787bp of 5'-flanking region of the resistin promoter. A chromatin immunoprecipitation assay also showed that FOXO1 bound the resistin promoter at nucleotide regions of -1539 to -1366bp and -1016 to -835bp, but not at the regions of -795 to -632bp. Results of this study suggest that FOXO1 transcription factor likely activates the expression of adipocyte resistin gene via direct association with the upstream resistin promoter.

Cycloheximide stimulates suppressor of cytokine signaling-3 gene expression in 3T3-L1 adipocytes via the extracellular signal-regulated kinase pathway.

Suppressor of cytokine signaling (SOCS)-3 can act as a regulator of energy metabolism and cytokine signaling in fat cells. It is regulated by hormones and toxicological factors. However, the action of cycloheximide on expression of adipocyte SOCS-3 gene is unknown. Using 3T3-L1 adipocytes, we found that cycloheximide up-regulated SOCS-3 mRNA expression in dose- and time-dependent manners. Treatment with actinomycin D prevented cycloheximide-stimulated SOCS-3 mRNA expression, suggesting that the effect of cycloheximide requires new mRNA synthesis. While cycloheximide was shown to increase activities of MEK1 and JNK, signaling was demonstrated to be inhibited by pretreatment with either MEK1 inhibitors U0126 and PD98059, or with the JNK inhibitor SP600125. U0126 and PD98059, respectively, reduced cycloheximide-stimulated SOCS-3 mRNA expression, but SP600125 did not antagonize cycloheximide effect. Moreover, cycloheximide was observed to up-regulate expression of other SOCS family members, such as SOCS-1, -2, -4, -5, -6, -7, and cytokine-inducible SH2-containing protein (CIS)-1 mRNAs. Such effects varied with the dosage and duration of cycloheximide treatment. These results imply the functional MEK1/ERK-mediated pathway is necessary for the cycloheximide stimulation of SOCS-3 gene expression.

Endothelin-1 stimulates suppressor of cytokine signaling-3 gene expression in adipocytes.

Endothelin (ET)-1 and suppressor of cytokine signaling (SOCS)-3 were respectively found to regulate energy metabolism and hormone signaling in fat cells. Although ET-1 can also regulate the expression of SOCS-3-stimulating hormones, it is still unknown whether ET-1 regulates SOCS-3 gene expression. This study investigated the pathways involved in ET-1's modulation of SOCS-3 gene expression in 3T3-L1 adipocytes. ET-1 upregulated SOCS-3 mRNA and protein expression in dose- and time-dependent manners. The concentration of ET-1 that increased SOCS-3 mRNA levels by 250-400% was ∼100nM with 2-4h of treatment. Treatment with actinomycin D prevented ET-1-stimulated SOCS-3 mRNA expression, suggesting that the effect of ET-1 requires new mRNA synthesis. Pretreatment with the ET type A receptor (ET(A)R) antagonist, BQ-610, but not the ET type B receptor (ET(B)R) antagonist, BQ-788, prevented the stimulatory effect of ET-1 on SOCS-3 gene expression. The specific inhibitors of either MEK1 (U-0126 and PD-98059), JAK (AG-490), JNK (SP-600125), or PI3K (LY-294002 and wortmannin) reduced ET-1-increased levels of SOCS-3 mRNA and respectively inhibited ET-1-stimulated activities of MEK1, JAK, JNK, and PI3K. These results imply that the ET(A)R, ERK, JAK, JNK, and PI3K are functionally necessary for ET-1's stimulation of SOCS-3 gene expression. Moreover, ET-1 was observed to upregulate expressions of SOCS-1, -2, -3, -4, -5, and -6 mRNAs, but not SOCS-7 or cytokine-inducible SH2-containing protein-1 mRNAs. This suggests that ET-1 selectively affects particular types of SOCS family members. Changes in SOCS gene expressions induced by ET-1 may help explain the mechanism by which ET-1 modulates hormone signaling of adipocytes.