Association of metabolic health and obesity with coronary heart disease in adult cancer survivors.

BACKGROUND: The metabolically healthy obese (MHO) phenotype is associated with an increased risk of coronary heart disease (CHD) in the general population. However, association of metabolic health and obesity phenotypes with CHD risk in adult cancer survivors remains unclear. We aimed to investigate the associations between different metabolic health and obesity phenotypes with incident CHD in adult cancer survivors. METHODS: We used National Health Insurance Service (NHIS) to identify a cohort of 173,951 adult cancer survivors aged more than 20 years free of cardiovascular complications. Metabolically healthy nonobese (MHN), MHO, metabolically unhealthy nonobese (MUN), metabolically unhealthy obese (MUO) phenotypes were created using as at least three out of five metabolic health criteria along with obesity (body mass index ≥ 25.0 kg/m2). We used Cox proportional hazards model to assess CHD risk in each metabolic health and obesity phenotypes. RESULTS: During 1,376,050 person-years of follow-up, adult cancer survivors with MHO phenotype had a significantly higher risk of CHD (hazard ratio [HR] = 1.52; 95% confidence intervals [CI]: 1.41 to 1.65) as compared to those without obesity and metabolic abnormalities. MUN (HR = 1.81; 95% CI: 1.59 to 2.06) and MUO (HR = 1.92; 95% CI: 1.72 to 2.15) phenotypes were also associated with an increased risk of CHD among adult cancer survivors. CONCLUSIONS: Adult cancer survivors with MHO phenotype had a higher risk of CHD than those who are MHN. Metabolic health status and obesity were jointly associated with CHD risk in adult cancer survivors.

Increased risk of ischemic stroke associated with elevated gamma-glutamyl transferase level in adult cancer survivors: a population-based cohort study.

Adult cancer survivors may have an increased risk of developing ischemic stroke, potentially influenced by cancer treatment-related factors and shared risk factors with stroke. However, the association between gamma-glutamyl transferase (GGT) levels and the risk of ischemic stroke in this population remains understudied. Therefore, our study aimed to examine the relationship between GGT levels and the risk of ischemic stroke using a population-based cohort of adult cancer survivors. A population-based cohort of adult cancer survivors was derived from the National Health Insurance Service-Health Screening Cohort between 2003 and 2005 who survived after diagnosis of primary cancer and participated in the biennial national health screening program between 2009 and 2010. Cox proportional hazards model adjusted for sociodemographic factors, health status and behavior, and clinical characteristics was used to investigate the association between GGT level and ischemic stroke in adult cancer survivors. Among 3095 adult cancer survivors, 80 (2.58%) incident cases of ischemic stroke occurred over a mean follow-up of 8.2 years. Compared to the lowest GGT quartile, the hazard ratios (HRs) for ischemic stroke were 1.56 (95% CI 0.75-3.26), 2.36 (95% CI 1.12-4.99), and 2.40 (95% CI 1.05-5.46) for the second, third, and fourth sex-specific quartiles, respectively (Ptrend = 0.013). No significant effect modification was observed by sex, insurance premium, and alcohol consumption. High GGT level is associated with an increased risk of ischemic stroke in adult cancer survivors independent of sex, insurance premium, and alcohol consumption.

Effects of an Aging Management Program for Middle-aged Women on Resilience and Successful Aging.

PURPOSE: The purpose of this study was to examine the effects of an aging management program on the resilience and successful aging of middle-aged women. METHODS: A quasi-experimental study with a non-equivalent control and pre-post test design was used. The participants were 39 middle-aged women living in urban areas in Korea. The experimental group (n=22) received the aging management program for a total of 10 weeks, 90 minutes to 120 minutes per week. The aging management program consisted of strategies to enhance the behavior, promotion conditions, and habits of the program, including various activities for middle-aged women. The data were analyzed using χ² tests, independent t-tests, and repeated measures analysis of variance with the SPSS/WIN 21.0 program. RESULTS: The resilience score of the experimental group was significantly higher level than the score of the control group in the time-to-group interactions (F=3.70, p=0.029). The successful aging score of the experimental group was significantly higher than the score of the control group in the time-to-group interactions (F=5.86, p=0.004). However, the sub-hypotheses of resilience (self-regulation and interpersonal relationships) and successful aging (physical aging adaptation and psychological age adaptation) were partially accepted. CONCLUSIONS: The aging management program for middle-aged women was identified as an effective intervention for promoting resilience and successful aging in middle-aged women. Therefore, this suggests that the aging care program could be a useful intervention program to improve the mental health of middle-aged women living in communities.

Protein tyrosine phosphatase profiling studies during brown adipogenic differentiation of mouse primary brown preadipocytes.

There is a correlation between obesity and the amount of brown adipose tissue; however, the molecular mechanism of brown adipogenic differentiation has not been as extensively studied. In this study, we performed a protein tyrosine phosphatase (PTP) profiling analysis during the brown adipogenic differentiation of mouse primary brown preadipocytes. Several PTPs, including PTPRF, PTPRZ, and DUSP12 showing differential expression patterns were identified. In the case of DUSP12, the expression level is dramatically downregulated during brown adipogenesis. The ectopic expression of DUSP12 using a retroviral expression system induces the suppression of adipogenic differentiation, whereas a catalytic inactive DUSP12 mutant showed no effect on differentiation. These results suggest that DUSP12 is involved in brown adipogenic differentiation and may be used as a target protein for the treatment or prevention of obesity by the regulation of brown adipogenic differentiation.

Structural basis for the dephosphorylating activity of PTPRQ towards phosphatidylinositide substrates.

Unlike other classical protein tyrosine phosphatases (PTPs), PTPRQ (PTP receptor type Q) has dephosphorylating activity towards phosphatidylinositide (PI) substrates. Here, the structure of the catalytic domain of PTPRQ was solved at 1.56 Šresolution. Overall, PTPRQ adopts a tertiary fold typical of other classical PTPs. However, the disordered M6 loop of PTPRQ surrounding the catalytic core and the concomitant absence of interactions of this loop with residues in the PTP loop results in a flat active-site pocket. On the basis of structural and biochemical analyses, it is proposed that this structural feature might facilitate the accommodation of large substrates, making it suitable for the dephosphorylation of PI substrates. Moreover, subsequent kinetic experiments showed that PTPRQ has a strong preferences for PI(3,4,5)P3 over other PI substrates, suggesting that its regulation of cell survival and proliferation reflects downregulation of Akt signalling.

Molecular imaging of conscious, unrestrained mice with AwakeSPECT.

UNLABELLED: We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. METHODS: The capability of the system for motion-corrected imaging was demonstrated with a (99m)Tc-pertechnetate phantom, (99m)Tc-methylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand (123)I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. RESULTS: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of (123)I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. CONCLUSION: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake.

Phosphoproteomic analysis of electroacupuncture analgesia in an inflammatory pain rat model.

The phosphorylation changes of nociceptive signaling proteins in the spinal cord dorsal horn (SCDH) are important in creating exaggerated pain following peripheral inflammation. Electroacupuncture (EA) has been widely used to relieve acute and chronic inflammatory pain in human and experimental pain models. In the present study, we performed a phosphoproteomic analysis to investigate whether EA alters protein phosphorylation in SCDH to attenuate pain development. Inflammatory hyperalgesia was induced by intraplantar injection of complete Freund's adjuvant (CFA) into the rat hind paw. EA treatment at ST36 and SP6 acupoints alleviated thermal hyperalgesia of the CFA-induced inflammatory pain model rats. The SCDH proteins from the control, inflammatory pain model and EA treatment rats were separated by 2-dimensional gel electrophoresis and the alterations in phosphoproteins were detected by Pro-Q Diamond staining. Eight proteins were differentially phosphorylated following EA treatment in the inflammatory pain model. Aldolase C, nascent polypeptide-associated complex α, stress-induced phosphoprotein 1 and heat shock protein 90 were identified as phosphoproteins whose expression was increased, whereas GDP dissociation inhibitor 1, thiamine triphosphatase, phosphoglycerate kinase 1 and 14-3-3 γ were phosphoproteins whose expression was decreased. This is the first phosphoproteomic screening study to elucidate the working mechanisms of EA analgesia. The results suggest that the regulation of cellular pathways in which the identified proteins are involved may be associated with an EA analgesic mechanism.

Protein tyrosine phosphatase profiling analysis of HIB-1B cells during brown adipogenesis.

A number of evidence have been accumulated that the regulation of reversible tyrosine phosphorylation, which can be regulated by the combinatorial activity of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs), plays crucial roles in various biological processes including differentiation. There are a total of 107 PTP genes in the human genome, collectively referred to as the "PTPome." In this study, we performed PTP profiling analysis of the HIB-1B cell line, a brown preadipocyte cell line, during brown adipogenesis. Through RT-PCR and real-time PCR, several PTPs showing differential expression pattern during brown adipogenesis were identified. In the case of PTP-RE, it was shown to decrease significantly until 4 days after brown adipogenic differentiation, followed by a dramatic increase at 6 days. The overexpression of PTP-RE led to decreased brown adipogenic differentiation via reducing the tyrosine phosphorylation of the insulin receptor, indicating that PTP-RE functions as a negative regulator at the early stage of brown adipogenesis.

Glyceraldehyde-3-phosphate, a glycolytic intermediate, prevents cells from apoptosis by lowering S-nitrosylation of glyceraldehyde-3-phosphate dehydrogenase.

Glyceraldehyde-3-phosphate (G-3-P), the substrate of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), is a key intermediate in several metabolic pathways. Recently, we reported that G-3-P directly inhibits caspase-3 activity in a reversible noncompetitive mode, suggesting the intracellular G-3-P level as a cell fate decision factor. It has been known that apoptotic stimuli induce the generation of NO, and NO S-nitrosylates GAPDH at the catalytic cysteine residue, which confers GAPDH the ability to bind to Siah-1, an E3 ubiquitin ligase. The GAPDH-Siah-1 complex is translocated into the nucleus and subsequently triggers the apoptotic process. Here, we clearly showed that intracellular G-3-P protects GAPDH from S-nitrosylation at above a certain level, and consequently maintains the cell survival. In case G-3-P drops below a certain level as a result of exposure to specific stimuli, G-3-P cannot inhibit S-nitrosylation of GAPDH anymore, and consequently GAPDH translocates with Siah-1 into the nucleus. Based on these results, we suggest that G-3-P functions as a molecule switch between cell survival and apoptosis by regulating S-nitrosylation of GAPDH.

Comparative proteomic analysis of human somatic cells, induced pluripotent stem cells, and embryonic stem cells.

Induced pluripotent stem cells (iPSCs) are somatic cells that have been reprogrammed to a pluripotent state via introduction of defined transcription factors. iPSCs are a valuable resource for regenerative medicine, but whether iPSCs are identical to embryonic stem cells (ESCs) remains unclear. In this study, we performed comparative proteomic analyses of human somatic cells [human newborn foreskin fibroblasts (hFFs)], human iPSCs (hiPSCs) derived from hFFs, and H9 human ESCs (hESCs). We reprogrammed hFFs to a pluripotent state using 4 core transcription factors: Oct4 (O), Sox2 (S), Klf4 (K), and c-Myc (M). The proteome of hiPSCs induced by 4 core transcription factors was relatively similar to that of hESCs. However, several proteins, including dUTPase, GAPDH, and FUSE binding protein 3, were differentially expressed between hESCs and hiPSCs, implying that hiPSCs are not identical to hESCs at the proteomic level. The proteomes of iPSCs induced by introducing 3, 5, or 6 transcription factors were also analyzed. Our proteomic profiles provide valuable insight into the factors that contribute to the similarities and differences between hESCs and hiPSCs and the mechanisms of reprogramming.

RPTPµ tyrosine phosphatase promotes adipogenic differentiation via modulation of p120 catenin phosphorylation.

Adipocyte differentiation can be regulated by the combined activity of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). In particular, PTPs act as key regulators in differentiation-associated signaling pathways. We recently found that receptor-type PTPµ (RPTPµ) expression is markedly increased during the adipogenic differentiation of 3T3-L1 preadipocytes and mesenchymal stem cells. Here, we investigate the functional roles of RPTPµ and the mechanism of its involvement in the regulation of signal transduction during adipogenesis of 3T3-L1 cells. Depletion of endogenous RPTPµ by RNA interference significantly inhibited adipogenic differentiation, whereas RPTPµ overexpression led to an increase in adipogenic differentiation. Ectopic expression of p120 catenin suppressed adipocyte differentiation, and the decrease in adipogenesis by p120 catenin was recovered by introducing RPTPµ. Moreover, RPTPµ induced a decrease in the cytoplasmic p120 catenin expression by reducing its tyrosine phosphorylation level, consequently leading to enhanced translocation of Glut-4 to the plasma membrane. On the basis of these results, we propose that RPTPµ acts as a positive regulator of adipogenesis by modulating the cytoplasmic p120 catenin level. Our data conclusively demonstrate that differentiation into adipocytes is controlled by RPTPµ, supporting the utility of RPTPµ and p120 catenin as novel target proteins for the treatment of obesity.

RKIP downregulation induces the HBx-mediated Raf-1 mitochondrial translocation.

The Raf-1 kinase inhibitory protein (RKIP) can regulate multiple key signaling pathways. Specifically, RKIP binds to Raf-1 kinase and inhibits the Ras-Raf-1-MEK1/2- ERK1/2 pathway. Additionally, Raf-1 has been shown to translocate to mitochondria and thereby protect cells from stress-mediated apoptosis. Recently, HBx was found to stimulate the mitochondrial translocation of Raf-1, contributing to the anti-apoptotic effect. We found that RKIP was downregulated during HBx-mediated hepatocarcinogenesis. In this study, we show that RKIP bound to Raf-1 and consequently inhibited the translocation of Raf-1 into mitochondria. This promoted the apoptosis of cells treated with apoptotic stimulus. Thus, the downregulation of RKIP increased the level of free Raf-1 and thereby elevated the mitochondrial translocation of Raf-1 during HBx-mediated hepatocarcinogenesis. The elevated Raf-1 mitochondrial translocation induced the increased anti-apoptotic effect and subsequently promoted HBx-mediated hepatocarcinogenesis.

Annexin A4 interacts with the NF-kappaB p50 subunit and modulates NF-kappaB transcriptional activity in a Ca2+-dependent manner.

Previously, we identified annexin A4 (ANXA4) as a candidate substrate of caspase-3. Proteomic studies were performed to identify interacting proteins with a view to determining the roles of ANXA4. ANXA4 was found to interact with the p105. Subsequent studies revealed that ANXA4 interacts with NF-kappaB through the Rel homology domain of p50. Furthermore, the interaction is markedly increased by elevated Ca(2+) levels. NF-kappaB transcriptional activity assays demonstrated that ANXA4 suppresses NF-kappaB transcriptional activity in the resting state. Following treatment with TNF-alpha or PMA, ANXA4 also suppressed NF-kappaB transcriptional activity, which was upregulated significantly early after etoposide treatment. This difference may be due to the intracellular Ca(2+) level. Additionally, ANXA4 translocates to the nucleus together with p50, and imparts greater resistance to apoptotic stimulation by etoposide. Our results collectively indicate that ANXA4 differentially modulates the NF-kappaB signaling pathway, depending on its interactions with p50 and the intracellular Ca(2+) ion level.

Regulation of adipogenic differentiation by LAR tyrosine phosphatase in human mesenchymal stem cells and 3T3-L1 preadipocytes.

Mesenchymal stem cells (MSCs) are multipotent adult stem cells that can differentiate into a variety of mesodermal-lineage cells. MSCs have significant potential in tissue engineering and therapeutic applications; however, the low differentiation and proliferation efficiencies of these cells in the laboratory are fundamental obstacles to their therapeutic use, mainly owing to the lack of information on the detailed signal-transduction mechanisms of differentiation into distinct lineages. With the aid of protein-tyrosine-phosphatase profiling studies, we show that the expression of leukocyte common antigen related (LAR) tyrosine phosphatase is significantly decreased during the early adipogenic stages of MSCs. Knockdown of endogenous LAR induced a dramatic increase in adipogenic differentiation, whereas its overexpression led to decreased adipogenic differentiation in both 3T3-L1 preadipocytes and MSCs. LAR reduces tyrosine phosphorylation of the insulin receptor, in turn leading to decreased phosphorylation of the adaptor protein IRS-1 and its downstream molecule Akt (also known as PKB). We propose that LAR functions as a negative regulator of adipogenesis. Furthermore, our data support the possibility that LAR controls the balance between osteoblast and adipocyte differentiation. Overall, our findings contribute to the clarification of the mechanisms underlying LAR activity in the differentiation of MSCs and suggest that LAR is a candidate target protein for the control of stem-cell differentiation.

Involvement of PTP-RQ in differentiation during adipogenesis of human mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are self-renewable multipotent progenitor cells with the capacity to differentiate into several distinct mesenchymal lineages. While MSCs display significant potential in tissue engineering and therapeutic applications, the regulatory mechanisms underlying the differentiation of these cells are yet to be established. Phosphorylation is a post-translational modification that plays a significant role in diverse biological phenomena. In this study, to mine the protein tyrosine phosphatases (PTPs) involved in adipogenesis of human MSCs, differential expression of human PTPs was examined using RT-PCR analysis. Among the 107 human PTPs, PTP-RQ was dramatically downregulated during the early phase of adipogenesis. PTP-RQ is classified as a receptor-type III PTP with phosphatidylinositol phosphatase (PIPase) activity. Overexpression of PTP-RQ consistently led to reduced differentiation of MSCs into adipocytes via decreasing the phosphatidyl inositol phosphate level in cells, and consequently downregulating Akt/PKB phosphorylation. Our results collectively suggest that PTP-RQ is a useful target protein for regulating the differentiation of MSCs into adipocytes, and may be used to develop novel drugs for the treatment of obesity.

Phosphoproteomic analysis of AML14.3D10 cell line as a model system of eosinophilia.

Eosinophils act as effectors in the inflammatory reactions of allergic diseases including atopic dermatitis. Atopic dermatitis patients and others with allergic disorders suffer from eosinophilia, an accumulation of eosinophils due to increased survival or decreased apoptosis of eosinophils. In this study, a differential phosphoproteome analysis of AML14.3D10 eosinophil cell line after treatment with IL-5 or dexamethasone was conducted in an effort to identify the phosphoproteins involved in the proliferation or apoptosis of eosinophils. Proteins were separated by 2-DE and alterations in phosphoproteins were then detected by Pro-Q Diamond staining. The significant quantitative changes were shown in nineteen phosphoproteins including retinoblastoma binding protein 7, MTHSP75, and lymphocyte cytosolic protein 1. In addition, seven phosphoproteins including galactokinase I, and proapolipoprotein, were appeared after treatment with IL-5 or dexamethasone. Especially, the phospho-APOE protein was down-regulated in IL-5 treated AML14.3D10, while the more heavily phosphorylated APOE form was induced after dexamethasone treatment. These phosphoproteome data for the AML14.3D10 cell line may provide clues to understand the mechanism of eosinophilia as well as allergic disorders including atopic dermatitis.

Phosphoproteomic analysis of neuronal cell death by glutamate-induced oxidative stress.

Oxidative stress is one of the major causes of neuronal cell death in disorders such as perinatal hypoxia and ischemia. Protein phosphorylation is the most significant PTM of proteins and plays an important role in stress-induced signal transduction. Thus, the analysis of alternative protein phosphorylation states which occur during oxidative stress-induced cell death could provide valuable information regarding cell death. In this study, a reference phosphoproteome map of the mouse hippocampal cell line HT22 was constructed based on 125 spots that were identified by MALDI-TOF or LC-ESI-Q-TOF-MS analysis. In addition, proteins of HT22 cells at various stages of oxidative stress-induced cell death were separated by 2-DE and alterations in phosphoproteins were detected by Pro-Q Diamond staining. A total of 17 spots showing significant quantitative changes and seven newly appearing spots were identified after glutamate treatment. Splicing factor 2, peroxiredoxin 2, S100 calcium binding protein A11, and purine nucleoside phosphorylase were identified as up- or down-regulated proteins. CDC25A, caspase-8, and cyp51 protein appeared during oxidative stress-induced cell death. The data in this study from phosphoproteomic analysis provide a valuable resource for the understanding of HT22 cell death mechanisms mediated by oxidative stress.