Sleep fragmentation promotes NADPH oxidase 2-mediated adipose tissue inflammation leading to insulin resistance in mice.

BACKGROUND: Short sleep has been implicated in higher risk of obesity in humans, and is associated with insulin resistance. However, the effects of fragmented sleep (SF) rather than curtailed sleep on glucose homeostasis are unknown. METHODS: Wild-type and NADPH oxidase 2 (Nox2) null male mice were subjected to SF or sleep control conditions for 3 days to 3 weeks. Systemic and visceral adipose tissue (VAT) insulin sensitivity tests, glucose tolerance test, fluorescence-activated cell sorting and immunohistochemistry for macrophages and its sub-types (M1 and M2), and Nox expression and activity were examined. RESULTS: Here we show that SF in the absence of sleep curtailment induces time-dependent insulin resistance, in vivo and also in vitro in VAT. Oxidative stress pathways were upregulated by SF in VAT, and were accompanied by M1 macrophage polarization. SF-induced oxidative stress, inflammation and insulin resistance in VAT were completely abrogated in genetically altered mice lacking Nox2 activity. CONCLUSIONS: These studies imply that SF, a frequent occurrence in many disorders and more specifically in sleep apnea, is a potent inducer of insulin resistance via activation of oxidative stress and inflammatory pathways, thereby opening the way for therapeutic strategies.

Activation of glycogen synthase by insulin in 3T3-L1 adipocytes involves c-Cbl-associating protein (CAP)-dependent and CAP-independent signaling pathways.

In adipose and muscle, insulin stimulates glucose uptake and glycogen synthase activity. Phosphatidylinositol 3-kinase (PI3K) activation is necessary but not sufficient for these metabolic actions of insulin. The insulin-stimulated translocation of phospho-c-Cbl to lipid rafts, via its association with CAP, comprises a second pathway regulating GLUT4 translocation. In 3T3-L1 adipocytes, overexpression of a dominant negative CAP mutant (CAP Delta SH3) completely blocked the insulin-stimulated glucose transport and glycogen synthesis but only partially inhibited glycogen synthase activation. In contrast, CAP Delta SH3 expression did not affect glycogen synthase activation by insulin in the absence of extracellular glucose. Moreover, CAP Delta SH3 has no effect on the PI3K-dependent activation of protein phosphatase-1 or phosphorylation of glycogen synthase kinase-3. These results indicate blockade of the c-Cbl/CAP pathway directly inhibits insulin-stimulated glucose uptake, which results in secondary inhibition of glycogen synthase activation and glycogen synthesis.

Distinctive regulatory and metabolic properties of glycogen-targeting subunits of protein phosphatase-1 (PTG, GL, GM/RGl) expressed in hepatocytes.

Glycogen-targeting subunits of protein phosphatase-1 facilitate interaction of the phosphatase with enzymes of glycogen metabolism. We have shown that overexpression of one member of the family, protein targeting to glycogen (PTG), causes large increases in glycogen storage in isolated hepatocytes or intact rat liver. In the current study, we have compared the metabolic and regulatory properties of PTG (expressed in many tissues), with two other members of the gene family, G(L) (expressed primarily in liver) and G(M)/R(Gl) (expressed primarily in striated muscle). Adenovirus-mediated expression of these proteins in hepatocytes led to the following key observations. 1) G(L) has the highest glycogenic potency among the three forms studied. 2) Glycogen synthase activity ratio is much higher in G(L)-overexpressing cells than in PTG or G(M)/R(Gl)-overexpressing cells. Thus, at moderate levels of G(L) overexpression, glycogen synthase activity is increased by insulin treatment, but at higher levels of G(L) expression, insulin is no longer required to achieve maximal synthase activity. In contrast, cells with high levels of PTG overexpression retain dose-dependent regulation of glycogen synthesis and glycogen synthase enzyme activity by insulin. 3) G(L)- and G(M)/R(Gl)-overexpressing cells exhibit a strong glycogenolytic response to forskolin, whereas PTG-overexpressing cells are less responsive. This difference may be explained in part by a lesser forskolin-induced increase in glycogen phosphorylase activity in PTG-overexpressing cells. Based on these results, we suggest that expression of either G(L) or G(M)/R(Gl) in liver of diabetic animals may represent a strategy for lowering of blood glucose levels in diabetes.

A case for including spirituality in quality of life measurement in oncology.

Most of the commonly used quality of life (QOL) instruments in oncology do not include spirituality as a core domain. However, previous research suggests that spirituality might be an important aspect of QOL for cancer patients and that it may, in fact, be especially salient in the context of life-threatening illness. This study used a large (n=1610) and ethnically diverse sample to address three questions relevant to including spirituality in QOL measurement: (1) Does spirituality demonstrate a positive association with QOL?; (2) Is this association unique?; and (3) Is there clinical utility in including spirituality in QOL measurement? Spirituality, as measured by the Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being (FACIT-Sp), was found to be associated with QOL to the same degree as physical well-being, a domain unquestioned in its importance to QOL. The significant association between spirituality and QOL was unique, remaining after controlling for core QOL domains as well as other possible confounding variables. Furthermore, spiritual well-being was found to be related to the ability to enjoy life even in the midst of symptoms, making this domain a potentially important clinical target. It is concluded that these results support the move to the biopsychosocialspiritual model for QOL measurement in oncology.

Age-related differences in the quality of life of breast carcinoma patients after treatment.

BACKGROUND: The objective of this study was to compare the quality of life (QOL) of younger (< or =50 years) versus older (>50 years) women on recent completion of treatment of breast carcinoma. METHODS: Data reported herein were obtained from a baseline assessment of 304 breast carcinoma patients. These patients were enrolled in a multiinstitutional, randomized trial testing a psychosocial telephone counseling intervention for breast carcinoma patients immediately after treatment. The assessment was made using a self-administered (mail) questionnaire, with an overall response rate of 86%. Included in this questionnaire were standardized measures of QOL using the Functional Assessment of Cancer Therapy-Breast instrument, the Center for Epidemiologic Studies Depression Scale, and the Impact of Event Scale. RESULTS: Comparisons of baseline data analyzed according to age approximating menopausal status (< or =50 years and >50 years) indicated that younger women reported significantly greater QOL disturbance. QOL was significantly worse for younger women globally (P = 0.021), and with regard to domains of emotional well-being (P = 0.0002) and breast carcinoma specific concerns (P = 0.022). Furthermore, symptoms of depression (P = 0.041) and disease specific intrusive thoughts (P = 0.013) were significantly worse for younger women. No significant sexual dysfunction or body image differences were noted. CONCLUSIONS: Results from this analysis suggest that younger women with breast carcinoma should be considered to be at high risk for QOL disruption and significant clinical distress. Targeted interventions for this cohort are recommended.

The activation of glycogen synthase by insulin switches from kinase inhibition to phosphatase activation during adipogenesis in 3T3-L1 cells.

The effects of insulin and platelet-derived growth factor (PDGF) on glycogen synthase activation were compared in 3T3-L1 fibroblasts and adipocytes. In the fibroblasts, PDGF elicited a stronger phosphorylation of mitogen-activated protein kinase (MAPK) and AKT than did insulin. Both agents caused a comparable stimulation of receptor autophosphorylation, MAPK, and phosphatidylinositol 3-kinase (PI3-K) activation in the adipocytes. However, adipogenesis resulted in the uncoupling of PI3-K activation by PDGF from subsequent AKT phosphorylation. The relative contributions of glycogen synthase kinase-3 (GSK-3) inactivation and protein phosphatase-1 (PP1) activation in the regulation of glycogen synthase in both cell types were evaluated. Insulin and PDGF caused a small increase in glycogen synthase a activity in the fibroblasts. Additionally, both agents caused a similar inhibition of GSK-3, while having no effect on PP1 activity. Following differentiation, insulin treatment resulted in a 5-fold stimulation of glycogen synthase, whereas PDGF was without effect. Both agents caused a comparable inhibition of GSK-3 activity in the adipocytes, whereas only insulin activated PP1. Finally, wortmannin completely blocked the stimulation of PP1 by insulin in 3T3-L1 adipocytes, indicating that PI3-K inhibition can impinge on PP1 activation. Cumulatively these results suggest that the weak activation of glycogen synthase in 3T3-L1 fibroblasts is mediated by GSK-3 inactivation, whereas in the more metabolically active adipocytes, the insulin-specific activation of glycogen synthase is mediated by PP1 activation.

Regulation of protein phosphatase 2A activity by caspase-3 during apoptosis.

Although the available evidence suggests that whereas the caspase family plays a major role in apoptosis, they are not the sole stimulators of death. A random yeast two-hybrid screen of a lymphocyte cDNA library (using caspase-3 as the bait) found an interaction between caspase-3 and the regulatory subunit Aalpha of protein phosphatase 2A. This protein was found to be a substrate for caspase-3, but not caspase-1, and could compete effectively against either a protein or synthetic peptide substrate. In Jurkat cells induced to undergo apoptosis with anti-Fas antibody, protein phosphatase 2A (PP2A) activity increased 4.5-fold after 6 h. By 12 h, the regulatory Aalpha subunit could no longer be detected in cell lysates. There was no change in the amount of the catalytic subunit. The effects on PP2A could be prevented by the caspase family inhibitors acetyl-Asp-Glu-Val-Asp (DEVD) aldehyde or Ac-DEVD fluoromethyl ketone. The mitogen-activated protein (MAP) kinase pathway is regulated by PP2A. At 12 h after the addition of anti-Fas antibody, a decrease in the amount of the phosphorylated forms of MAP kinase was observed. Again, this loss of activated MAP kinase could be prevented by the addition of DEVD-cho or DEVD-fmk. These data are consistent with a pathway whereby induction of apoptosis activates caspase-3. This enzyme then cleaves the regulatory Aalpha subunit of PP2A, increasing its activity. These data show that the activated PP2A will then effect a change in the phosphorylation state of the cell. These data provide a link between the caspases and signal transduction pathways.

Telephone counseling of breast cancer patients after treatment: a description of a randomized clinical trial.

The Telephone Counseling Trial for Breast Cancer Survivors is a randomized, controlled study designed to test the impact of a telephone-based counseling intervention on quality of life of early-stage breast cancer patients who have completed adjuvant treatment. A psychoeducational counseling model is utilized to promote adaptive coping to re-entry stressors and survivorship issues. Adaptation is fostered through the exploration of thematic materials, application of active coping strategies, encouragement of a personal expression of the breast cancer experience and the provision of psychological support. Patients are being recruited in collaboration with two NCI-designated clinical cooperative oncology groups: the Eastern Cooperative Oncology Group (ECOG) and the Southwest Cooperative Oncology Group (SWOG). The recruitment goal is 400 breast cancer survivors with Stage 1, Stage 2 and Stage 3 disease (with no greater than 10 positive lymph nodes involved). Patients are being enrolled by data managers on-site during their last treatment visit. The intervention is being delivered by the Cancer Information and Counseling Line (CICL) of the AMC Cancer Research Center. It includes 16 telephone outcalls which are delivered over a 12-month period. Primary outcome measures are quality of life, mood, social support, self-efficacy, and sexual functioning, assessed at baseline, 3, 6, 12 and 18 months follow-up. This article provides a description of the intervention protocol and study design. It is argued that this study could provide a model for developing and testing other psychosocial interventions within clinical cooperative groups nationwide.

The regulation of glycogen synthase by protein phosphatase 1 in 3T3-L1 adipocytes. Evidence for a potential role for DARPP-32 in insulin action.

The stimulation of glycogen-targeted protein phosphatase 1 (PP1), glycogen synthase, and glycogen synthesis by insulin was examined during the differentiation of 3T3-L1 fibroblasts into adipocytes. Insulin treatment barely changed the low levels of glycogen synthesis measured in fibroblasts. Following differentiation into adipocytes, insulin increased glycogen synthesis up to 40-fold. After further culturing of the adipocytes for a week, insulin stimulated glycogen accumulation 700-fold. Differentiation of 3T3-L1 cells also resulted in the increased expression of glycogen synthase and in increases in both total glycogen synthase activity and -fold stimulation by insulin. While the levels of PP1 protein were unchanged by differentiation, PP1 specific activity decreased over 60%, although sensitivity to insulin treatment was augmented. Concurrently, levels of the PP1 inhibitor protein DARPP-32 were dramatically induced upon 3T3-L1 adipogenesis. DARPP-32 in both 3T3-L1 and primary rat adipocytes was exclusively localized to the particulate fractions, including the glycogen-enriched pellet. PP1 activity from 3T3-L1 adipocytes exhibited a kinetic lag in vitro, which was not present in fibroblast extracts. Insulin pretreatment of the adipocyte cells overcame the in vitro lag in PP1 activity, resulting in up to 5-fold stimulation of PP1 activity being measured at early assay time points. These results suggest that in 3T3-L1 adipocytes, DARPP-32 may maintain glycogen-targeted PP1 activity in a low basal state, priming the phosphatase for stimulation by insulin.

Role of protein targeting to glycogen (PTG) in the regulation of protein phosphatase-1 activity.

We have recently cloned from 3T3-L1 adipocytes a novel glycogen-targeting subunit of protein phosphatase-1, termed PTG (Printen, J. A., Brady, M. J., and Saltiel, A. R. (1997) Science 275, 1475-1478). Differentiation of 3T3-L1 fibroblasts into highly insulin-responsive adipocytes resulted in a marked increase in PTG expression. Immobilized glutathione S-transferase (GST)-PTG fusion protein specifically bound either PP1 or phosphorylase a. Addition of soluble GST-PTG to 3T3-L1 lysates increased PP1 activity against 32P-labeled phosphorylase a by decreasing the Km of PP1 for phosphorylase 5-fold, while having no effect on the Vmax of the dephosphorylation reaction. Alternatively, PTG did not affect PP1 activity against hormone-sensitive lipase. PTG was not a direct target of intracellular signaling, as insulin or forskolin treatment of cells did not activate a kinase capable of phosphorylating PTG in vivo or in vitro. Finally, PTG decreased the ability of DARPP-32 to inhibit PP1 activity from 3T3-L1 adipocyte lysates. These data cumulatively suggest that PTG increases PP1 activity against specific proteins by several distinct mechanisms.

Reliability and validity of the Functional Assessment of Cancer Therapy-Breast quality-of-life instrument.

PURPOSE: This is the first published report on the validation of the Functional Assessment of Cancer Therapy-Breast (FACT-B), a 44-item self-report instrument designed to measure multidimensional quality of life (QL) in patients with breast cancer. The FACT-B consists of the FACT-General (FACT-G) plus the Breast Cancer Subscale (BCS), which complements the general scale with items specific to QL in breast cancer. The FACT-B was developed with an emphasis on patients' values and brevity and is available in nine languages. METHODS AND RESULTS: Two validation samples were used for this report. The first (n = 47) was tested twice over a 2-month period to assess sensitivity to change. Significant sensitivity to change in performance status rating (PSR) was demonstrated for the FACT-B total score, the Physical Well-Being (PWB) subscale, the Functional Well-Being (FWB) subscale, and the BCS. Sensitivity to change in QL as measured by the Functional Living Index-Cancer (FLIC) was documented in the FACT-B total score, PWB, FWB, and Emotional Well-Being (EWB). Additional validity and reliability data were obtained from a larger sample (n = 295). The alpha coefficient (internal consistency) for the FACT-B total score was high (alpha = .90), with subscale alpha coefficients ranging from .63 to .86. Evidence supported test-retest reliability, as well as convergent, divergent, and known groups validity. CONCLUSION: The FACT-B is appropriate for use in oncology clinical trials, as well as in clinical practice. It demonstrates ease of administration, brevity, reliability, validity, and sensitivity to change.

Mitogen-activated protein kinase kinase inhibition does not block the stimulation of glucose utilization by insulin.

Insulin stimulates the activity of mitogen-activated protein kinase (MAPK) via its upstream activator, MAPK kinase (MEK), a dual specificity kinase that phosphorylates MAPK on threonine and tyrosine. The potential role of MAPK activation in insulin action was investigated with the specific MEK inhibitor PD98059. Insulin stimulation of MAPK activity in 3T3-L1 adipocytes (2.7-fold) and L6 myotubes (1.4-fold) was completely abolished by pretreatment of cells with the MEK inhibitor, as was the phosphorylation of MAPK and pp90Rsk, and the transcriptional activation of c-fos. Insulin receptor autophosphorylation on tyrosine residues and activation of phosphatidylinositol 3'-kinase were unaffected. Pretreatment of cells with PD98059 had no effect on basal and insulin-stimulated glucose uptake, lipogenesis, and glycogen synthesis. Glycogen synthase activity in extracts from 3T3-L1 adipocytes and L6 myotubes was increased 3-fold and 1.7-fold, respectively, by insulin. Pretreatment with 10 microM PD98059 was without effect. Similarly, the 2-fold activation of protein phosphatase 1 by insulin was insensitive to PD98059. These results indicate that stimulation of the MAPK pathway by insulin is not required for many of the metabolic activities of the hormone in cultured fat and muscle cells.

Physical and psychosocial status of adults one-year after bone marrow transplantation: a prospective study.

Assessment of the impact of bone marrow transplantation (BMT) on long-term physical and psychosocial functioning has been hampered by a paucity of prospective research. While evidence suggests that many adult BMT recipients experience deficits in physical and psychosocial functioning > or = 1 year following BMT, whether these deficits existed prior to BMT is not known. Observed post-BMT deficits could be attributable to conventional treatments received prior to BMT and thus could have antedated BMT. The physical and psychosocial status of 28 adult BMT recipients was assessed prior to BMT and 12-16 months after BMT. Analysis of group means indicated few significant differences between pre- and post-BMT assessments. However, inspection of residual change scores suggested that physical and psychosocial status improved following BMT for some individuals, while that of others declined. Analysis of residual change scores indicated that males and older patients at time of BMT reported the largest declines in physical and psychosocial status. Longer follow-up is necessary to determine whether decrements observed 12-16 months after BMT reflect a slower process of post-BMT recovery or whether they constitute fairly permanent deficits.

Insulin stimulates the tyrosine phosphorylation of caveolin.

The specialized plasma membrane structures termed caveolae and the caveolar-coat protein caveolin are highly expressed in insulin-sensitive cells such as adipocytes and muscle. Stimulation of 3T3-L1 adipocytes with insulin significantly increased the tyrosine phosphorylation of caveolin and a 29-kD caveolin-associated protein in caveolin-enriched Triton-insoluble complexes. Maximal phosphorylation occurred within 5 min, and the levels of phosphorylation remained elevated for at least 30 min. The insulin-dose responses for the tyrosine phosphorylation of caveolin and the 29-kD caveolin-associated protein paralleled those for the phosphorylation of the insulin receptor. The stimulation of caveolin tyrosine phosphorylation was specific for insulin and was not observed with PDGF or EGF, although PDGF stimulated the tyrosine phosphorylation of the 29-kD caveolin-associated protein. Increased tyrosine phosphorylation of caveolin, its associated 29-kD protein, and a 60-kD protein was observed in an in vitro kinase assay after incubation of the caveolin-enriched Triton-insoluble complexes with Mg-ATP, suggesting the presence of an intrinsic tyrosine kinase in these complexes. These fractions contain only trace amounts of the activated insulin receptor. In addition, these complexes contain a 60-kD kinase detected in an in situ gel kinase assay and an approximately 60 kD protein that cross-reacts with an antibody against the Src-family kinase p59Fyn. Thus, the insulin-dependent tyrosine phosphorylation of caveolin represents a novel, insulin-specific signal transduction pathway that may involve activation of a tyrosine kinase downstream of the insulin receptor.

'Returning to normal' following bone marrow transplantation: outcomes, expectations and informed consent.

The psychosocial impact of bone marrow transplantation (BMT) was investigated in 172 disease-free adult BMT survivors drawn from five different BMT treatment centers. Respondents were a mean of 43.5 months after BMT. Both questionnaire and interview assessments were utilized. Survivors' perceptions of whether they had 'returned to normal' following BMT, recollections of pre-BMT expectations for returning to normal and current psychological distress were assessed. The results indicated that only a minority of respondents considered themselves to have 'returned to normal' following BMT. Reports of less than normal physical, cognitive, occupational, sexual and/or interpersonal functioning were common. In contrast, few patients reported pre-BMT expectations for such. Discordance between pre-BMT expectations for returning to normal and current functional status was associated with greater current psychological distress. Finally, despite the presence of any functional deficits and despite any discordance between pre-BMT expectations and current functional status, survivors' evaluations of their decision to pursue BMT were generally quite positive. Results are discussed in terms of their implications for: (1) the process of obtaining informed consent for BMT, and (2) clinical strategies for enhancing post-BMT psychological adjustment.

Health locus of control and psychological distress in cancer patients: interactive effects of context.

Delineation of the relationship between health locus of control (HLOC) and psychological adjustment in chronic disease has been hampered by the failure to consider the moderating effect of contextual factors. The extent to which HLOC beliefs match the control realities in a situation (Reality Matching hypothesis) as well as the degree of threat (Threat hypothesis) posed by the situation were hypothesized to moderate the HLOC-distress relationship. Distress, disease severity (i.e., threat), and HLOC were assessed in 69 individuals with malignant disease undergoing evaluation for bone marrow transplantation. Hierarchical regression analyses indicated that the HLOC-distress relationship was moderated by disease severity and treatment history (i.e., whether an individual had failed prior cancer therapy). However, in some instances, the specific interaction relationships obtained differed from those evident in previous research with ESRD patients. It was concluded that there is no simple main effect relationship between HLOC beliefs and psychological adjustment. Rather, this relationship is best described by joint consideration of factors descriptive of the context in which the individual is embedded.

Psychosocial factors predictive of survival after allogeneic bone marrow transplantation for leukemia.

Previous research suggesting a link between psychosocial variables and survival after bone marrow transplant (BMT) has been limited by: a) retrospective assessment of psychosocial variables; and b) failure to concurrently examine a comprehensive set of disease, treatment, and demographic variables potentially related to post-BMT survival. The present study prospectively assessed psychosocial variables (depressed mood, functional quality of life, and mental adjustment to cancer) that have been linked to survival after BMT and/or malignant disease. Study participants (N = 42) received allogeneic BMT for either acute or chronic leukemia. Analyses using Cox proportional hazards regression indicated that quality of bone marrow graft match was the only disease, treatment, or demographic variable significantly associated with post-BMT survival (p = .05). Addition of psychosocial variables to a multivariate Cox regression model including quality of graft match suggested that an attitude toward cancer characterized by "anxious preoccupation" (p = .008), as well as poorer functional quality of life (p = .052), were each independently associated with poorer post-BMT survival. Further research is necessary to identify the mechanisms by which psychosocial variables could contribute to post-BMT survival.

Rapid and sustained phosphorylation of a calmodulin-binding protein (CaM-BP100) in NGF-treated PC12 cells.

Nerve growth factor (NGF) treatment of PC12 cells led to the rapid phosphorylation of a calmodulin-binding protein of 100 kDa (CaM-BP100) identified on blot overlays with 125I-labeled CaM. The effect was detected as a retardation in the mobility of the protein by an apparent 10 kDa on SDS gels. The mobility shift was complete within 5 min and was maintained for 24 h in the continued presence of NGF. The protein was present in both the soluble and crude particulate fractions, and the gel mobility shift occurred in both fractions. Epidermal growth factor elicited a similar response, but the mobility shift was reversed within 12 h. The gel retardation was due to phosphorylation of CaM-BP100, as it could be reversed if cytoplasmic extracts were held under dephosphorylating conditions at 37 degrees C for 10 min prior to electrophoresis; dephosphorylation was inhibited by okadaic acid but not vanadate, suggesting the participation of a Ser/Thr phosphatase. Treatment with either acid or alkaline phosphatase also reversed the mobility shift. CaM-BP100 phosphorylation was stimulated by 12-O-tetradecanoylphorbol-13-acetate in intact cells, but the effect of NGF did not involve a protein kinase C-dependent process, because it occurred in PC12 cells depleted of protein kinase C. The phosphorylation event appeared to be due to an NGF-stimulated protein kinase, as mixing extracts from NGF-treated cells with extracts from control cells in the presence of ATP and Mg2+ reconstituted the mobility shift in vitro. CaM-BP100 appears to be a minor cellular phosphoprotein, as 32P labeling of the protein could not be detected in crude cell extracts. These results suggest that receptor tyrosine kinases communicate with at least one component of the Ca2+/calmodulin-signaling pathway early in signal transduction.