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1.
Biomedicines ; 10(10)2022 Oct 17.
Article in English | MEDLINE | ID: mdl-36289868

ABSTRACT

Our previous studies demonstrated that collapsin response mediator protein 2 (CRMP2) is associated with obesity and, in addition, that hyperglycemia-suppressed CRMP2 augments malignant traits of colorectal cancer and is associated with advanced tumor stage. Regulation of CRMP2 profile was further explored in this study using 3T3-L1 pre-adipocyte adipogenesis as a study model for illustrating the roles of CRMP2 in metabolic homeostasis. Hyperglycemia inhibited expression of CRMP2, adipogenic machinery and adipocyte markers. CRMP2 displayed f-CRMP2 (62~66 kDa) and s-CMRP2 (58 kDa) isoforms at the growth arrest phase. Expression of s-CRMP2 was coupled with the mitotic clonal expansion (MCE) phase to direct cell proliferation and rapidly down-regulated in post-mitotic cells. In the late differentiation phase, f-CRMP2 was co-localized with tubulin in the cortical area. Insulin-enhanced CRMP2-glucose transporter 4 (GLUT4) co-localization and CRMP2 puncta on lipid droplets (LDs) suggested participation of CRMP2 in GLUT4 translocation and LD fusion. Collectively, the CRMP2 functional profile must be finely controlled to adjust cytoskeletal stability for meeting dynamic cellular needs. Manipulating the s-CRMP2/f-CRMP2 ratio and thus the cytoskeleton dynamics is anticipated to improve glucose uptake and insulin sensitivity. In summary, our data provide molecular evidence explaining the functions of CRMP2 in physiological, pathological and disease progression in metabolic homeostasis and disorders related to metabolic abnormalities, including cancer.

2.
Cells ; 11(4)2022 02 18.
Article in English | MEDLINE | ID: mdl-35203376

ABSTRACT

BACKGROUND: Common demographic risk factors are identified in colorectal cancer (CRC) and type 2 diabetes mellitus (DM), nevertheless, the molecular link and mechanism for CRC-DM comorbidity remain elusive. Dysregulated glycogen synthase kinase-3 beta under metabolic imbalance is suggested to accelerate CRC pathogenesis/progression via regulating collpasin response mediator protein-2 (CRMP2). Accordingly, roles of CRMP2 in CRC and CRC-DM patients were investigated for elucidating the molecular convergence of CRC and DM. METHODS: CRMP2 profile in tumor tissues from CRC and CRC-DM patients was investigated to explore the link between CRC and DM etiology. Meanwhile, molecular mechanism of glucose to regulate CRMP2 profile and CRC characteristics was examined in vitro and in vivo. RESULTS: CRMP2 was significantly lower in tumor lesions and associated with advanced tumor stage in CRC-DM patients. Physiological hyperglycemia suppressed CRMP2 expression/activity and augmented malignant characteristics of CRC cells. Hyperglycemia promotes actin de-polymerization, cytoskeleton flexibility and cell proliferation/metastasis by downregulating CRMP2 profile and thus contributes to CRC disease progression. CONCLUSIONS: This study uncovers molecular evidence to substantiate and elucidate the link between CRC and T2DM, as well as characterizing the roles of CRMP2 in CRC-DM. Accordingly, altered metabolic adaptations are promising targets for anti-diabetic and cancer strategies.


Subject(s)
Colorectal Neoplasms , Diabetes Mellitus, Type 2 , Hyperglycemia , Intercellular Signaling Peptides and Proteins , Nerve Tissue Proteins , Colorectal Neoplasms/complications , Comorbidity , Diabetes Mellitus, Type 2/complications , Humans , Intercellular Signaling Peptides and Proteins/genetics , Nerve Tissue Proteins/genetics , Phosphorylation
3.
Int J Mol Sci ; 21(15)2020 Jul 31.
Article in English | MEDLINE | ID: mdl-32752112

ABSTRACT

The expansion of adipose tissue mass is the primary characteristic of the process of becoming obesity, which causes chronic adipose inflammation and is closely associated with type 2 diabetes mellitus (T2DM). Adipocyte hypertrophy restricts oxygen availability, leading to microenvironmental hypoxia and adipose dysfunction. This study aimed at investigating the effects of oxygenated water (OW) on adipocyte differentiation (adipogenesis) and the metabolic function of mature adipocytes. The effects of OW on adipogenesis and the metabolic function of mature adipocytes were examined. Meanwhile, the in vivo metabolic effects of long-term OW consumption on diet-induced obesity (DIO) mice were investigated. OW inhibited adipogenesis and lipid accumulation through down-regulating critical adipogenic transcription factors and lipogenic enzymes. While body weight, blood and adipose parameters were not significantly improved by long-term OW consumption, transient circulatory triglyceride-lowering and glucose tolerance-improving effects were identified. Notably, hepatic lipid contents were significantly reduced, indicating that the DIO-induced hepatic steatosis was attenuated, despite no improvements in fibrosis and lipid contents in adipose tissue being observed in the OW-drinking DIO mice. The study provides evidence regarding OW's effects on adipogenesis and mature adipocytes, and the corresponding molecular mechanisms. OW exhibits transient triglyceride-lowering and glucose tolerance-improving activity as well as hepatic steatosis-attenuating functions.


Subject(s)
Adipogenesis/drug effects , Fatty Liver/drug therapy , Lipogenesis/drug effects , Water/metabolism , 3T3-L1 Cells , Adipocytes/drug effects , Adipose Tissue/drug effects , Adipose Tissue/metabolism , Animals , Cell Differentiation/drug effects , Diet, High-Fat/adverse effects , Fatty Liver/metabolism , Fatty Liver/pathology , Humans , Mice , Mice, Obese/genetics , Mice, Obese/metabolism , Obesity/genetics , Obesity/metabolism , Obesity/pathology , Obesity/prevention & control , Oxygen/metabolism , Water/pharmacology
4.
Int J Mol Sci ; 21(6)2020 Mar 21.
Article in English | MEDLINE | ID: mdl-32245267

ABSTRACT

As emerging evidence suggesting neurodegenerative diseases and metabolic diseases have common pathogenesis, we hypothesized that the neurite outgrowth-controlling collapsin response mediator protein 2 (CRMP2) was involved in energy homeostasis. Therefore, putative roles of CRMP2 in adipocyte differentiation (adipogenesis) and lipid metabolism were explored and addressed in this study. CRMP2 expression profiles were in vitro and in vivo characterized during adipogenic process of 3T3-L1 pre-adipocytes and diet-induced obese (DIO) mice, respectively. Effects of CRMP2 on lipid metabolism and deposits were also analyzed. Our data revealed that CRMP2 expression pattern was coupled with adipogenic stages. CRMP2 overexpression inhibited cell proliferation at MCE phase, and significantly reduced lipid contents by down-regulating adipogenesis-driving transcription factors and lipid-synthesizing enzymes. Interestingly, GLUT4 translocation and the lipid droplets fusion were disturbed in CRMP2-silencing cells by affecting actin polymerization. Moreover, adipose CRMP2 was significantly increased in DIO mice, indicating CRMP2 is associated with obesity. Accordingly, CRMP2 exerts multiple functions in adipogenesis and lipid deposits through mediating cell proliferation, glucose/lipid metabolism and cytoskeleton dynamics. The present study identifies novel roles of CRMP2 in mediating adipogenesis and possible implication in metabolic disorders, as well as provides molecular evidence supporting the link of pathogenesis between neurodegenerative diseases and metabolic abnormalities.


Subject(s)
Adipocytes/metabolism , Cytoskeleton/metabolism , Intercellular Signaling Peptides and Proteins/metabolism , Lipid Metabolism/genetics , Nerve Tissue Proteins/metabolism , Obesity/metabolism , 3T3-L1 Cells , Actins/metabolism , Adipocytes/cytology , Adipogenesis/genetics , Animals , Cell Proliferation/genetics , Diet, High-Fat , Gene Knockdown Techniques , Gene Silencing , Glucose/metabolism , Glucose Transporter Type 4/metabolism , Glycogen Synthase Kinase 3 beta/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Lipids , Male , Mice , Mice, Inbred C57BL , Nerve Tissue Proteins/genetics , Obesity/genetics , RNA, Small Interfering , Signal Transduction/genetics , Up-Regulation
5.
Mediators Inflamm ; 2019: 4182015, 2019.
Article in English | MEDLINE | ID: mdl-31814802

ABSTRACT

Anti-inflammatory cytokine interleukin-4 (IL-4) promotes glucose tolerance and insulin sensitivity while reduces lipid deposits. However, the effects of IL-4 on energy metabolism in muscle, the largest insulin-targeting organ, remain obscure. The study aimed at addressing the roles of IL-4 in myocyte differentiation (myogenesis) and energy metabolism of muscle cells. Effects of IL-4 on myogenesis, and interaction between IL-4 and insulin on glucose metabolism of C2C12 myoblasts and the terminal differentiated myocytes were analyzed. IL-4 improved GLUT4 translocation and tended to elevate glucose uptake by boosting insulin signaling. In diabetic mice, transient and long-term IL-4 showed differential effects on insulin signaling and efficacy. The study provides evidence to address the roles of IL-4 in mediating whole-body muscle reservoir and glucose metabolism, as well as the interaction between immune responses and energy homeostasis. IL-4 has dual potential to act as an adjuvant therapeutic target for sarcopenia to preserve muscle mass and insulin resistance to improve insulin sensitivity, which implicates the regulation of immune system to the muscle differentiation and exercise performance.


Subject(s)
Interleukin-4/pharmacology , Muscle Cells/drug effects , Muscle Cells/metabolism , Muscle Development/drug effects , Animals , Biological Transport/drug effects , Blotting, Western , Cell Differentiation/drug effects , Cell Line , Glucose/metabolism , Glucose Transporter Type 4/metabolism , Male , Mice , Mice, Inbred C57BL , Microscopy, Fluorescence , Myoblasts/drug effects , Myoblasts/metabolism , Reverse Transcriptase Polymerase Chain Reaction
6.
Sci Rep ; 9(1): 11974, 2019 08 19.
Article in English | MEDLINE | ID: mdl-31427606

ABSTRACT

Accumulating evidence indicates that inflammation participates in the pathophysiological progress from insulin resistance, obesity, metabolic abnormalities, and type 2 diabetes mellitus. Our previous study reveals that interleukin-4 (IL-4) inhibits adipogenesis and promotes lipolysis to decrease lipid deposits by enhancing the activity of hormone sensitive lipase (HSL). The present study further dissects and characterizes the molecular mechanism of IL-4 in regulating HSL expression and lipolytic activity in the terminal differentiated 3T3-L1 mature adipocytes. Our results showed that IL-4 increased cAMP which then enhanced PKA activity and subsequent phosphorylation of HSL and perilipin. The phosphorylated HSL (p-HSL) translocated from cytoplasm to the surface of lipid droplets and exhibited lipolytic function. After being phosphorylated, p-perilipin also facilitated lipolysis through interacting with p-HSL. The in vitro findings were further verified by in vivo study in which IL-4 exhibited pro-lipolytic activity and enhanced HSL activity. In summary, the net outcome of IL-4 treatment is to reduce lipid storage by promoting lipolysis through enhancing HSL activity via cAMP/PKA pathway, the major route leading to lipolysis.


Subject(s)
Interleukin-4/metabolism , Lipid Metabolism , Sterol Esterase/genetics , Sterol Esterase/metabolism , 3T3-L1 Cells , Adipocytes/metabolism , Animals , Cyclic AMP-Dependent Protein Kinases/metabolism , Enzyme Activation/drug effects , Enzyme Stability/drug effects , Gene Expression Regulation/drug effects , Interleukin-4/pharmacology , Lipid Metabolism/drug effects , Lipolysis/drug effects , Mice , Models, Biological , Phosphorylation , Proteolysis/drug effects
7.
Oxid Med Cell Longev ; 2018: 6923187, 2018.
Article in English | MEDLINE | ID: mdl-30584465

ABSTRACT

Type 2 diabetes mellitus (T2DM), with dysregulated hepatic gluconeogenesis as the major cause of fasting hyperglycemia, is closely associated with chronic inflammation. We previously demonstrated interleukin-4 (IL-4) improves insulin sensitivity and glucose tolerance while reducing lipid deposits. The present study examined the in vitro effects of IL-4 on insulin signaling molecules, glucose uptake, and lipid metabolism in hepatocytes, as well as in vivo effects on hepatic adiposity, for elucidating the roles of IL-4 in hepatic energy metabolism. Potential interaction between IL-4 and insulin in regulating hepatic metabolism was also investigated. Our results showed that IL-4 enhanced Akt and GSK-3α/ß phosphorylations, which in turn promoted glycogen synthesis. IL-4 not only potentiated basal glucose uptake by upregulating glucose transporter 2 expression but also promoted insulin-induced glucose uptake. Additionally, IL-4 increased triglyceride contents through facilitating free fatty acid uptake and expression/activity of lipogenic enzymes. The major effects of IL-4 on the liver were to promote energy storage by boosting insulin-stimulated glucose uptake and lipid synthesis. This study provides evidence to implicate the novel roles of IL-4 in mediating hepatic glucose and lipid metabolism, interactions between immune responses and metabolic homeostasis, and the involvement of IL-4 in metabolic abnormalities.


Subject(s)
Glucose/metabolism , Hepatocytes/drug effects , Hepatocytes/metabolism , Insulin/pharmacology , Interleukin-4/pharmacology , Lipid Metabolism/drug effects , Animals , Blotting, Western , Diabetes Mellitus, Type 2/metabolism , Hep G2 Cells , Humans , Male , Mice, Inbred C57BL , Signal Transduction/drug effects , Triglycerides/metabolism
8.
Int J Med Sci ; 15(4): 395-402, 2018.
Article in English | MEDLINE | ID: mdl-29511375

ABSTRACT

Type 2 diabetes mellitus (T2DM) is associated with chronic inflammation, suggesting the metabolic abnormalities are originated from or exacerbated by cytokine overproduction. Cytokines and counter-regulatory molecules are crucial in keeping the balance of immune responses and, therefore, are potential candidates involved in T2DM etiology, development and complications. Our previous reports identify several significant associations between the genotypes of cytokine genes and T2DM and/or the clinical lipid parameters, which strongly suggest the participation of immune-regulatory molecules in lipid metabolism. The aim of this study is to determine the distribution of gene encoding cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), a T-cell negative regulator, in T2DM patients and health subjects. Genomic DNA was extracted from 287 Taiwanese T2DM patients and 278 ethnic- and age- matched healthy subjects, and two CTLA-4 polymorphisms (-318 C/T and +49 A/G) were analyzed by polymerase chain reaction-restriction fragment length polymorphism. Intriguingly, CTLA-4 -318 genotype was associated with circulatory triglycerides in T2DM subjects (P=0.019) although no significant association between CTLA-4 -318 (P=0.119) and +49 (P=0.2) genotypes with T2DM was identified. In addition, CTLA-4 +49 genotype was significantly associated with the ratio between total cholesterol and high-density lipoprotein (P=0.004) in control subjects. Our results suggest that CTLA-4 may be involved in lipid metabolism and affect T2DM disease progression and/or the development of diabetic complications although this gene does not represent a major risk factor for T2DM.


Subject(s)
CTLA-4 Antigen/genetics , Diabetes Mellitus, Type 2/genetics , Genetic Predisposition to Disease , Promoter Regions, Genetic , Adult , Aged , Asian People , Diabetes Mellitus, Type 2/pathology , Female , Genotype , Humans , Male , Middle Aged , Polymorphism, Restriction Fragment Length , T-Lymphocytes, Cytotoxic/metabolism , T-Lymphocytes, Cytotoxic/pathology
9.
Metabolism ; 72: 1-17, 2017 07.
Article in English | MEDLINE | ID: mdl-28641777

ABSTRACT

OBJECTIVE: Adipogenesis determines the number of adipocytes which is increased when individuals become obese. Mitochondria undergo remarkable morphological and functional changes during adipogenesis. PTEN-induced kinase 1 (PINK1) is pivotal to maintain mitochondrial homeostasis in neural cells. The present study aimed at investigating effects of PINK1 on adipogenesis and energy metabolism. METHODS: Expression of presenilin associated rhomboid-like protein (PARL), PINK1 and Parkin, as well as the interaction among these proteins was temporally examined during adipogenesis. In addition, the alterations of mitochondrial mass and the energy metabolism were also analyzed. RESULTS: Adipogenic process can be dissected into 3 stages according to the participation of PARL-PINK1-Parkin system. (1) When pre-adipocytes are switched to differentiation, f-PINK1 is subjected to PARL cleavage to generate s-PINK1 at the early stage of differentiation (0-4day). Mitochondrial mass is increased for generating ambient energy to meet the demands for cellular remodeling. (2) At the second stage (5-6day), s-PINK1 persistently accumulates in mitochondria and translocates into cytoplasm to mediate Parkin degradation. Mitochondria are fragmented to reduce their mass. (3) At the late stage (7-8day), only residual autophagy activity is remained when excess mitochondria have been eliminated. This mitochondria clearance maintains energy consumption of mature adipocytes at the minimal levels for storing energy. PARL silencing aborts adipogenesis by inhibiting PPARγ expression and the finely-orchestrated events. CONCLUSIONS: Our findings reveal the sequential adipogenic events directed by PARL-PINK1-Parkin system, add more evidence supporting the convergence of pathogenesis leading to neurodegenerative and metabolic diseases, and provide substantial information for developing novel therapeutic strategies by manipulating adipogenesis.


Subject(s)
Adipocytes/cytology , Cell Differentiation , Metalloproteases/metabolism , Mitochondrial Proteins/metabolism , Protein Kinases/metabolism , Signal Transduction/physiology , Ubiquitin-Protein Ligases/metabolism , Adipogenesis , Energy Metabolism , Humans , Metabolic Diseases/etiology , Metabolic Diseases/metabolism , Metabolic Diseases/pathology , Mitochondria/metabolism , Neurodegenerative Diseases/etiology , Neurodegenerative Diseases/metabolism , Neurodegenerative Diseases/pathology
10.
Oncol Rep ; 37(6): 3606-3616, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28498480

ABSTRACT

Miconazole (MIC), an antifungal agent, diplays anti­tumorigenic activity in various types of human cancers, including bladder cancer, yet its mechanism of antitumor action is not well understood. In the present study, we demonstrated that, in a cell viability assay, MIC had a cytotoxic effect on human T24, J82 and TSGH-8301 bladder cancer cells in a dose- and time­dependent manner, but did not exhibit significant toxicity toward human peripheral blood mononuclear cells. Cell cycle analysis revealed that MIC at concentrations of 25 and 50 µM significantly caused G0/G1 arrest in the TSGH-8301 and T24 cells, respectively. DNA fragmentation, mitochondrial membrane potential and western blot analyses showed that MIC inhibited the growth of these cells by both mitochondrial­mediated and death receptor (DR5)­mediated apoptosis pathways. Specifically, MIC increased the protein levels of p21 and p27, but decreased the expression of cyclin E1, CDK2 and CDK4. MIC augmented the expression of DR5, cleaved forms of caspase-3 -8 and -9, poly(ADP­ribose) polymerase and Bax, decreased the expression of Bcl-2 but increased cytosol levels of cytochrome c. Our results suggest that MIC inhibits the growth of bladder cancer cells through induction of G0/G1 arrest and apoptosis via activation of both the extrinsic and intrinsic apoptotic pathways. MIC is a potential chemotherapeutic agent for treating bladder cancer in humans.


Subject(s)
Apoptosis/drug effects , Miconazole/administration & dosage , Receptors, TNF-Related Apoptosis-Inducing Ligand/genetics , Urinary Bladder Neoplasms/drug therapy , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , DNA Fragmentation/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/metabolism , Membrane Potential, Mitochondrial/drug effects , Neoplasm Proteins/genetics , Signal Transduction/drug effects , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/pathology
12.
Oncol Rep ; 37(2): 1002-1010, 2017 Feb.
Article in English | MEDLINE | ID: mdl-28075477

ABSTRACT

Escin, a natural pentacyclic triterpenoid compound, exhibits antitumor effects on various types of human cancer cells, but its effect on human renal cancer cells has not been fully elucidated. In the present study, we demonstrated that escin elicits cytotoxic effects on human renal cancer cells (786-O and Caki-1) in a dose-dependent manner, as determined by MTT assay. Escin induced G2/M arrest, and then increased the sub-G1 population, Annexin V binding, activation of caspase-9/-3, cleavage of poly(ADP-ribose) polymerase (PARP) and Bax protein. Escin also decreased the anti-apoptotic protein levels of Bcl-2, X-linked inhibitor of apoptosis protein and survivin. In addition, escin induced reactive oxygen species (ROS) generation, leading to mitochondrial membrane potential dysfunction and inducing apoptosis in 786-O renal cancer cells, which were suppressed by antioxidants, such as NAC. Collectively, our results suggest that escin induces apoptosis via the intrinsic-mitochondrial apoptosis pathway through G2/M arrest and ROS generation in human renal cancer cells. Escin appears to have potential as a clinically useful chemotherapeutic agent for human renal cancer.


Subject(s)
Apoptosis/drug effects , Escin/pharmacology , Kidney Neoplasms/drug therapy , Reactive Oxygen Species/metabolism , Antineoplastic Agents/pharmacology , Caspases/metabolism , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Humans , Kidney Neoplasms/metabolism , Kidney Neoplasms/pathology , Mitochondria/drug effects , Mitochondria/metabolism , X-Linked Inhibitor of Apoptosis Protein/metabolism
13.
Medicine (Baltimore) ; 95(12): e2942, 2016 Mar.
Article in English | MEDLINE | ID: mdl-27015168

ABSTRACT

Tuberculosis, caused by Mycobacterium tuberculosis complex (MTBC) infections, is one of the most widespread infectious diseases worldwide. Nontuberculous mycobacteria (NTM) also cause chronic pulmonary infections, however, NTM infection is generally overlooked.This study analyzed the frequencies of MTBC and NTM clinical isolates from 181,132 specimens obtained from patients in Taiwan suspected of having a pulmonary mycobacterial infection from 2002 to 2014. The resistant rates to 4 first-line antibiotics (isoniazid, ethambutol, rifampicin, and streptomycin) of 9079 clinical MTBC isolates were also examined by the modified agar proportion method.Overall, the mycobacterial isolation rate was 8.65%, and this consisted of MTBC isolation rate of 5.01% and NTM isolation rate of 3.63%. The prevalence of MTBC isolates among the identified mycobacterial strains could be seen to decrease significantly from 82.5% in 2002 to 41.18% in 2014. Notably, the corresponding NTM prevalence increased 3.36 fold from 17.54% in 2002 to 58.82% in 2014. The frequencies of MTBC and NTM isolates showed a reciprocal trend with the crossing over occurring in the years 2010 and 2011. Although the resistance rates of the MTBC isolates to isoniazid and streptomycin were relatively stable over the study period, resistance rates of the MTBC isolates against rifampicin and ethambutol fluctuated across the study period. Overall, the incidence of multidrug resistance was relatively consistent at about 1.74%.The diagnosis, identification, and susceptibility tests for NTM should be standardized and integrated into appropriate clinical settings to cope with the increase in NTM infections. In addition, the documentation of the antibiotic resistance rates of MTBC clinical isolates to the antibiotic treatments most often clinically prescribed over a decade provides valuable clues and reference points for effective mycobacterial control.


Subject(s)
Antibiotics, Antitubercular/therapeutic use , Mycobacterium Infections, Nontuberculous/epidemiology , Tuberculosis, Multidrug-Resistant/epidemiology , Tuberculosis, Pulmonary/epidemiology , Cross-Sectional Studies , Humans , Incidence , Microbial Sensitivity Tests , Mycobacterium Infections, Nontuberculous/drug therapy , Taiwan , Tuberculosis, Multidrug-Resistant/drug therapy , Tuberculosis, Pulmonary/drug therapy
14.
Springerplus ; 4: 242, 2015.
Article in English | MEDLINE | ID: mdl-26110103

ABSTRACT

Obesity is closely associated with metabolic syndrome, type 2 diabetes mellitus (T2DM) and cardiovascular diseases. Our previous reports uncover the significant associations between interleukin-4 (IL-4)/IL-4 receptor genotypes and T2DM, as well as IL-4 genotypes and high density lipoprotein-cholesterol. Theses observations suggest that IL-4 harbors the capacity to regulate lipid metabolism. The present study is aimed at further elucidating regulatory roles of IL-4 to lipid metabolism by identifying putative proteins in 3T3-L1 adipocytes which are differentially expressed under IL-4 treatment. Proteins in mature 3T3-L1 adipocytes with altered expression levels under IL-4 treatment were identified by proteomic strategy. Our results revealed that IL-4 up-regulated levels of ATP synthase δ chain, Cytochrome c reductase, Pyrophsphatase and Vimentin, whereas, Alpha-enolase, Gelsolin, Vinculin and Valosin were down-regulated. These observations suggest that IL-4 promotes energy metabolism and inhibit lipid deposits in adipocytes by up-regulating proteins accelerating ATP synthesis. Our results suggest that IL-4 facilitates adipocytes metabolism to catabolism with a favorable condition for lipolysis. These catabolized lipids in adipocytes triggered by IL-4 might either be released into periphery or metabolized intracellularlly, and modulate systemic energy metabolism.

15.
J Lipid Res ; 55(3): 385-97, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24347527

ABSTRACT

Long-term cytokine-mediated inflammation is a risk factor for obesity and type 2 diabetes mellitus (T2DM). Our previous studies reveal significant associations between promoter single nucleotide polymorphisms (SNPs) of interleukin (IL)-4 and T2DM, as well as between SNPs in genes encoding IL-4/IL-4 receptor and high density lipoproteins. Our animal study reveals that IL-4 regulates glucose/lipid metabolism by promoting glucose tolerance and inhibiting lipid deposits. The above results strongly suggest the involvement of IL-4 in energy homeostasis. In the present study, we focus on examining the regulatory mechanism of IL-4 to lipid metabolism. Our results show that IL-4 inhibits adipogenesis by downregulating the expression of peroxisome proliferator-activated receptor-γ and CCAAT/enhancer-binding protein-α. Additionally, IL-4 promotes lipolysis by enhancing the activity and translocation of hormone sensitive lipase (HSL) in mature adipocytes, which suggests that IL-4 plays a pro-lipolytic role in lipid metabolism by boosting HSL activity. Our results demonstrate that IL-4 harbors pro-lipolysis capacity by inhibiting adipocyte differentiation and lipid accumulation as well as by promoting lipolysis in mature adipocytes to decrease lipid deposits. The above findings uncover the novel roles of IL-4 in lipid metabolism and provide new insights into the interactions among cytokine/immune responses, insulin sensitivity, and metabolism.


Subject(s)
Adipogenesis/drug effects , Interleukin-4/pharmacology , Lipid Metabolism/drug effects , Lipolysis/drug effects , 3T3-L1 Cells , Adipogenesis/genetics , Animals , Blotting, Western , CCAAT-Enhancer-Binding Protein-alpha/genetics , CCAAT-Enhancer-Binding Protein-alpha/metabolism , Carrier Proteins/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism , Gene Expression/drug effects , Lipid Metabolism/genetics , Lipolysis/genetics , Mice , Microscopy, Confocal , PPAR gamma/genetics , PPAR gamma/metabolism , Perilipin-1 , Phosphoproteins/metabolism , Phosphorylation/drug effects , Protein Transport/drug effects , RNA Interference , Reverse Transcriptase Polymerase Chain Reaction , STAT6 Transcription Factor/genetics , STAT6 Transcription Factor/metabolism , Signal Transduction/drug effects , Signal Transduction/genetics , Sterol Esterase/metabolism
16.
PLoS One ; 8(1): e54423, 2013.
Article in English | MEDLINE | ID: mdl-23349885

ABSTRACT

Human papillomavirus (HPV) infection is associated with non-smoking female lung cancer. Our previous report demonstrated that HPV 16 promotes lung tumor cell progression by up-regulating interleukin-17 (IL-17). IL-17 and its downstream signaling mediator, interleukin-8 (IL-8), have been implicated to modulate a variety of pro-angiogenic factors and play important roles in tumor angiogenesis and metastasis. Accordingly, we hypothesized that HPV infection may potentiate tumorigenic and metastatic characteristics of the infected cells through IL-8. The goal of the present study was to determine whether HPV infection in lung adenocarcinoma cells can promote the expression of IL-8 and metalloproteinases (MMPs) to make the transformed cells equipped with angiogenic and metastatic characteristics. The expression of IL-8 and MMPs in HPV 16 E6-transfected H1299 cells was analyzed to examine the hypothesis. HPV 16 E6 up-regulates pro-angiogenic MMP-2 and MMP-9 through inducing IL-8 expression in lung cancer cells. The results indicate that, in addition to cell proliferation-related machinery, HPV infection promotes the expression and activities of angiogenic and metastatic molecules in lung adenocarcinoma cells. The cytokines induced by HPV infection may work together to confer the malignant and tumorigenic potentials on the infected cells by promoting machineries of growth, angiogenic and metastatic characteristics.


Subject(s)
Adenocarcinoma/genetics , Interleukin-8/genetics , Lung Neoplasms/genetics , Matrix Metalloproteinase 2/genetics , Matrix Metalloproteinase 9/genetics , Adenocarcinoma/pathology , Cell Line, Tumor , Female , Gene Expression Regulation, Neoplastic , Human papillomavirus 16/genetics , Human papillomavirus 16/pathogenicity , Humans , Lung Neoplasms/pathology , Papillomavirus Infections/complications , Papillomavirus Infections/genetics , Papillomavirus Infections/virology , Up-Regulation
17.
Cytokine ; 59(2): 309-12, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22633285

ABSTRACT

The aim of this study is to investigate the correlation between E400A polymorphisms of interleukin-4 receptor α chain (IL-4Rα) and lipid metabolism. Genomic DNA from 121 type 2 diabetes mellitus (T2DM) patients and 113 non-diabetic, non-obese control study subjects were extracted, and their IL-4Rα E400A polymorphisms were analyzed by PCR-RFLP. The correlation between IL-4Rα E400A genotypes and study subjects' lipid profile was then examined. Significant associations of the IL-4Rα E400A genotypes and high density lipoprotein-cholesterol (HDL-C) levels among control individuals (p=0.007), as well as among the T2DM patients (p=0.029), were observed. Significant correlations between IL-4Rα E400A genotypes with blood pressure, as well as with blood urea nitrogen, were also observed in control subjects. Our results reveal that IL-4Rα may play certain roles in the lipid metabolism of Taiwanese population and suggest a novel link between lipid metabolism and the cytokine receptor.


Subject(s)
Cholesterol, HDL/blood , Genetic Association Studies , Genetic Predisposition to Disease , Interleukin-4 Receptor alpha Subunit/genetics , Polymorphism, Single Nucleotide/genetics , Case-Control Studies , Demography , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/genetics , Female , Gene Frequency/genetics , Humans , Male , Middle Aged
18.
Clin Biochem ; 44(17-18): 1370-4, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22008727

ABSTRACT

OBJECTIVES: Deficiency and/or decreased activity of methyltetrahydrofolate reductase (MTHFR) resulted from MTHFR variants are associated with hyperhomocysteinemia, an independent risk factor for vasculopathies in diabetic patients. The aim of this study was to examine MTHFR genotypes between healthy and type 2 diabetes mellitus (T2DM) subjects. DESIGN AND METHODS: MTHFR C677T and A1298C genotypes were analyzed in 56 T2DM and 62 healthy subjects by PCR-RFLP. Association between MTHFR genotypes and T2DM as well as the lipid/glucose metabolic indexes among T2DM subjects was statistically analyzed. RESULTS: No significance in the distribution of MTHFR genotypes between healthy and T2DM subjects is found. Besides, no significant associations between lipid/glucose metabolic indexes with MTHFR genotypes among diabetic patients are observed. CONCLUSIONS: These data indicate the previous observation that MTHFR polymorphisms may play some roles in the pathogenesis and complications of T2DM in Caucasians are unlikely to be applied in Taiwanese patients.


Subject(s)
Diabetes Mellitus, Type 2/genetics , Methylenetetrahydrofolate Reductase (NADPH2)/genetics , Adult , Case-Control Studies , Female , Gene Frequency , Genetic Association Studies , Genotype , Humans , Male , Middle Aged , Mutation, Missense , Polymorphism, Single Nucleotide , Sequence Analysis, DNA , Taiwan
19.
Trans R Soc Trop Med Hyg ; 105(3): 148-52, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21239028

ABSTRACT

Non-tuberculous mycobacteria (NTM) can cause chronic pulmonary infection, however, NTM infection is generally overlooked. This retrospective study analyzed the frequencies of Mycobacterium tuberculosis complex (MTBC) and NTM clinical isolates from 99 200 specimens of patients suspected with pulmonary mycobacterial infection in Taiwan from 2002-2007. A total of 8024 mycobacterial isolates, including 5349 MTBC and 2675 NTM, were obtained from the 99 200 specimens in the study period. The overall mycobacterial isolation rate was 8.09% (8024/99 200), and the overall MTBC and NTM isolation rate was 5.39% (5349/99 200) and 2.7% (2675/99 200), respectively. Notably, the prevalence of NTM isolates among the identified mycobacteria strains was increased 2.6 fold from 2002 (17.54%, 147/838) to 2007 (45.80%, 659/1439). The frequencies of MTBC and NTM isolates showed a reciprocal trend: the NTM isolation rates were steadily increasing while the overall mycobacterial isolation rates remained stable over the study period. Our results suggest that the diagnosis, identification and susceptibility tests for NTM should be standardized and integrated in clinical routines, for providing the information of NTM infection and prescribing clinical treatment in a more precise and efficient way to reduce the increasing NTM in the studied area.


Subject(s)
Body Fluids/microbiology , Mycobacterium/isolation & purification , Respiratory Tract Infections/microbiology , Tuberculosis, Pulmonary/microbiology , Female , Humans , Male , Mycobacterium/metabolism , Mycobacterium Infections, Nontuberculous/epidemiology , Respiratory Tract Infections/metabolism , Retrospective Studies , Taiwan/epidemiology , Tuberculosis, Pulmonary/metabolism
20.
Cancer ; 116(20): 4800-9, 2010 Oct 15.
Article in English | MEDLINE | ID: mdl-20578176

ABSTRACT

BACKGROUND: Human papillomavirus (HPV) 16/18 infection is associated with nonsmoking lung cancer. In this study, the authors investigated a putative correlation between interleukin (IL)-17 expression and HPV infection in clinical nonsmall cell lung cancer (NSCLC) tissues and examined the effects of HPV infection on a human NSCLC cell line. METHODS: IL-17 expression was investigated in 79 NSCLC tumor tissues by immunohistochemistry. Growth rate, IL-17 mRNA, and secreting protein levels were also examined in HPV 16/18 E6-transfected H1299 human NSCLC cells. RESULTS: Immunohistochemical data showed that 48.1% of lung tumors had IL-17 staining, which was significantly associated with patients' sex (P = .03), HPV infection (P = .002), and tumor stage (P = .03). Significant correlations of IL-17 with IL-6 (P < .001) and IL-17 with Mcl-1 (P < .001) expression were also observed. Cell growth rate was increased, and IL-17/Mcl-1 expression levels were elevated in HPV 16 E6-transfected H1299 cells. The transfected E6 oncoproteins can significantly up-regulate expression levels of IL-17 and antiapoptotic protein Mcl-1. CONCLUSIONS: The study suggests that HPV infection-induced IL-17 levels can stimulate Mcl-1 expression through the PI3K pathway and promote lung tumor cell progression through a p53- and IL-6-independent pathway.


Subject(s)
Gene Expression Regulation, Neoplastic , Interleukin-17/metabolism , Lung Neoplasms/virology , Oncogene Proteins, Viral/pharmacology , Papillomavirus Infections/genetics , Repressor Proteins/pharmacology , Tumor Virus Infections/genetics , Up-Regulation , Aged , Carcinoma, Non-Small-Cell Lung/genetics , Cell Line, Tumor , Cell Proliferation , Female , Humans , Interleukin-6/metabolism , Lung Neoplasms/genetics , Male , Myeloid Cell Leukemia Sequence 1 Protein , Papillomaviridae/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , Transfection
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