This prospective multisite Phase III clinical trial (Miami, New York, New Jersey) investigated the long-term (one year) effects of a 10-week group cognitive-behavioral stress management/expressive supportive therapy (CBSM+) intervention on disadvantaged minority women living with AIDS. The CBSM+ intervention consisted of 10-weekly group session of stress management, cognitive-behavioral skill training, relaxation techniques and expressive-supportive therapeutic strategies. The primary study outcome was self-reported depression scores as measured by the BDI. The CBSM+ Group intervention significantly decreased depression scores on the BDI for women following the intervention and maintained the decreased level at one-year follow-up.
The purpose of the present study was to determine whether changes in self-efficacy over time would be related to changes in disease progression markers (CD4, viral load) in a sample of women with AIDS. A self-efficacy measure was developed and two sub-scales emerged via factor analysis of 391 HIV-positive women: AIDS Self-efficacy and Cognitive Behavioral Skills Self-efficacy. Subsequently, the sub-scales and an additional adherence self-efficacy item were given to 56 HIV-positive women who were measured at two time points three months apart. Half of these women were randomly assigned to a CB intervention and half to a low intensity comparison condition. Increases in AIDS Self-efficacy over the three-month period were significantly related to increases in CD4 and decreases in viral load. Similarly, increases in Cognitive Behavioral Skills Self-efficacy were significantly related to decreases in distress over time. Findings were maintained within the intervention group alone. Interestingly, increases in cognitive behavioral skills self-efficacy and increases in the self-efficacy adherence item were also significantly related to decreases in viral load. Implications of the findings and suggestions for future research are discussed.
Objective: We tested the effects of a 10-week group-based cognitive–behavioral stress management/expressive–supportive therapy intervention (CBSM+) and a time-matched individual psychoeducational condition for 330 women with AIDS reporting moderate to poor baseline quality of life (QOL). The goal of this study was to examine treatment effects on total QOL and 11 QOL domains from baseline to post-intervention follow-up. Methods: Participants were assessed at baseline, randomized to a treatment condition (individual psychoeducation condition n=180, group-based CBSM+ condition n=150), participated in the intervention for 10 weeks and assessed again within 4 weeks following the intervention. QOL was measured using the Medical Outcomes Study-HIV-30. Results: QOL scores increased over the course of both interventions for the total QOL score and three QOL domains: cognitive functioning, health distress and overall health perceptions. While women in the CBSM+ group condition showed a significant improvement in mental health QOL from pre- to post-intervention, women in the individual condition did not change. No changes were observed for energy/fatigue, health transition, single-item overall QOL, pain, physical well-being, role functioning or social functioning in either condition. Conclusion: Results suggest that group-based CBSM+ and individual psychoeducational interventions are effective at improving certain aspects of QOL and that group-based CBSM+ may be particularly effective at increasing QOL related to mental health in this population of women with AIDS.
This study examined the effects of a ten-session cognitive-behavioural stress management/expressive supportive therapy (CBSM+) intervention on adherence to antiretroviral medication. Although the intervention was not designed to influence adherence, it was theorized that improved coping and social support could enhance adherence. Women with AIDS (N=174) in Miami, New York and New Jersey, USA, were randomized to a group CBSM+ intervention or individual control condition. Participants were African American (55%), Latina (18%) and Caribbean (18%) with drug (55%) and/or alcohol (32%) histories. Participants were assessed on self-reported medication adherence over seven days, HIV-related coping strategies and beliefs regarding HIV medication. Baseline overall self-reported adherence rates were moderate and related to coping strategies and HIV medication beliefs. Low adherent (80%) participants in the intervention condition increased their mean self-reported medication adherence (30.4% increase, t44=3.1, p<0.01), whereas low adherent women in the control condition showed a non-significant trend (19.6% increase, t44=2.0, p>0.05). The intervention did not improve adherence in this population; conditions did not differ significantly on self-reported adherence. Low adhering intervention participants significantly decreased levels of denial-based coping (F1,88=5.97, p<0.05). Results suggest that future interventions should utilize group formats and address adherence using coping and medication-knowledge focused strategies.
The endoplasmic reticulum (ER) is recognized as an important site for regulating cell surface expression of membrane proteins. We recently reported that only a fraction of newly synthesized delta opioid receptors could leave the ER and reach the cell surface, the rest being degraded by proteasomes. Here, we demonstrate that membrane-permeable opioid ligands facilitate maturation and ER export of the receptor, thus acting as pharmacological chaperones. We propose that these ligands stabilize the newly synthesized receptor in the native or intermediate state of its folding pathway, possibly by inducing stabilizing conformational constrains within the hydrophobic core of the protein. The receptor precursors that are retained in the ER thus represent fully competent folding intermediates that can be targets for pharmacological intervention aimed at regulating receptor expression and cellular responsiveness. The pharmacological chaperone action is independent of the intrinsic signaling efficacy of the ligand, since both agonists and antagonists were found to promote receptor maturation. This novel property of G protein-coupled receptor ligands may have important implications when considering their effects on cellular responsiveness during therapeutic treatments.
We have previously shown that only a fraction of the newly synthesized human δ opioid receptors is able to leave the endoplasmic reticulum (ER) and reach the cell surface (Petäjä-Repo, U. E, Hogue, M., Laperrière, A., Walker, P., and Bouvier, M. (2000) J. Biol. Chem. 275, 13727–13736). In the present study, we investigated the fate of those receptors that are retained intracellularly. Pulse-chase experiments revealed that the disappearance of the receptor precursor form (M r 45,000) and of two smaller species (M r 42,000 and 39,000) is inhibited by the proteasome blocker, lactacystin. The treatment also promoted accumulation of the mature receptor form (M r55,000), indicating that the ER quality control actively routes a significant proportion of rescuable receptors for proteasome degradation. In addition, degradation intermediates that included full-length deglycosylated (M r 39,000) and ubiquitinated forms of the receptor were found to accumulate in the cytosol upon inhibition of proteasome function. Finally, coimmunoprecipitation experiments with the β-subunit of the Sec61 translocon complex revealed that the receptor precursor and its deglycosylated degradation intermediates interact with the translocon. Taken together, these results support a model in which misfolded or incompletely folded receptors are transported to the cytoplasmic side of the ER membrane via the Sec61 translocon, deglycosylated and conjugated with ubiquitin prior to degradation by the cytoplasmic 26 S proteasomes.
Over 155 mutations within the V2 vasopressin receptor (AVPR2) gene are responsible for nephrogenic diabetes insipidus (NDI). The expression and subcellular distribution of four of these was investigated in transfected cells. These include a point mutation in the seventh transmembrane domain (S315R), a frameshift mutation in the third intracellular loop (804delG), and two nonsense mutations that code for AVPR2 truncated within the first cytoplasmic loop (W71X) and in the proximal portion of the carboxyl tail (R337X). RT-PCR revealed that mRNA was produced for all mutant receptor constructs. However, no receptor protein, as assessed by Western blot analysis, was detected for 804delG. The S315R was properly processed through the Golgi and targeted to the plasma membrane but lacked any detectable AVP binding or signaling. Thus, this mutation induces a conformational change that is compatible with endoplasmic reticulum (ER) export but dramatically affects hormone recognition. In contrast, the W71X and R337X AVPR2 were retained inside the cell as determined by immunofluorescence. Confocal microscopy revealed that they were both retained in the ER. To determine if calnexin could be involved, its interaction with the AVPR2 was assessed. Sequential coimmunoprecipitation demonstrated that calnexin associated with the precursor forms of both wild-type (WT) and mutant receptors in agreement with its general role in protein folding. Moreover, its association with the ER-retained R337X mutant was found to be longer than with the WT receptor suggesting that this molecular chaperone also plays a role in quality control and ER retention of misfolded G protein-coupled receptors.
The calcitonin receptor-like receptor (CRLR) is a seven-transmembrane domain (7TM) protein that requires the receptor activity-modifying protein 1 (RAMP1) to be expressed at the cell surface as a functional calcitonin gene-related peptide (CGRP) receptor. Although dimerization between the two molecules is well established, very little is known concerning the trafficking of this heterodimer upon receptor activation. Also, the subcellular localization and biochemical state of this ubiquitously expressed protein, in the absence of CRLR, remains poorly characterized. Here we report that when expressed alone RAMP1 is retained inside the cells where it is found in the endoplasmic reticulum and the Golgi predominantly as a disulfide-linked homodimer. In contrast, when expressed with CRLR, it is targeted to the cell surface as a 1:1 heterodimer with the 7TM protein. Although heterodimer formation does not involve intermolecular disulfide bonds, RAMP-CRLR association promotes the formation of intramolecular disulfide bonds within RAMP1. CGRP binding and receptor activation lead to the phosphorylation of CRLR and the internalization of the receptor as a stable complex. The internalization was found to be both dynamin- and beta -arrestin-dependent, indicating that the formation of a ternary complex between CRLR, RAMP1, and beta -arrestin leads to clathrin-coated pit-mediated endocytosis. These results therefore indicate that although atypical by its heterodimeric composition and its targeting to the plasma membrane, the CGRP receptor shares endocytotic mechanisms that are common to most classical 7TM receptors.
Over 150 mutations within the coding sequence of the V2 vasopressin receptor (V2R) gene are known to cause nephrogenic diabetes insipidus (NDI). A large number of these mutant receptors fail to fold properly and therefore are not routed to the cell surface. Here we show that selective, nonpeptidic V2R antagonists dramatically increase cell-surface expression and rescue the function of 8 mutant NDI-V2Rs by promoting their proper folding and maturation. A cell-impermeant V2R antagonist could not mimic these effects and was unable to block the rescue mediated by a permeant agent, indicating that the nonpeptidic antagonists act intracellularly, presumably by binding to and stabilizing partially folded mutants. In addition to opening new therapeutic avenues for NDI patients, these data demonstrate that by binding to newly synthesized mutant receptors, small ligands can act as pharmacological chaperones, promoting the proper folding and maturation of receptors and their targeting to the cell surface.
PURPOSE:The purposes of the present study were to assess the effects of a 12-wk laboratory based aerobic exercise program on cardiopulmonary function, CD4 cell count, and physician-assessed health status among symptomatic pre-AIDS HIV-infected individuals (N = 28) and to assess the degree to which ill health was associated with exercise relapse.METHODS:Responses to graded exercise test, physician-assessed health status, and CD4 cell counts were determined at baseline and 12-wk follow-up for participants randomly assigned to exercise or control conditions, and reasons for exercise noncompliance were recorded.RESULTS:Approximately 61% of exercise-assigned participants complied (> 50% attendance) with the exercise program, and analyses of exercise relapse data indicated that obesity and smoking status, but not exercise-associated illness, differentiated compliant from noncompliant exercisers. Compliant exercisers significantly improved peak oxygen consumption (VO2peak; 12%), oxygen pulse (O2pulse; 13%), tidal volume (TV; 8%), ventilation (VE; 17%), and leg power (25%) to a greater degree than control participants and noncompliant exercisers (all P < 0.05). Although no group differences in health status were found, a significant interaction effect indicated that noncompliant exercisers' CD4 cells declined (18%) significantly, whereas compliant exercisers' cell counts significantly increased (13%; P < 0.05).CONCLUSION:We conclude that although aerobic exercise can improve cardiopulmonary functioning in symptomatic HIV-infected individuals with minimal health risks, attention to factors associated with exercise adherence is warranted.
1033 Pulmonary complications occur in over 40% of persons infected with HIV-1 disease. The purpose of this study was to determine if there were any differences in lung function at rest and during maximal graded exercise between HIV-1 seropositive and seronegative men at rest and during a maximal graded exercise test. HIV-1 seropositive and seronegative, trained and untrained men between the ages of 18 and 45 (n=40) performed three trials each for forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), vital capacity (VC), and maximum voluntary ventilation (MVV) to examine lung function at rest. Immediately following the resting pulmonary assessment, a graded exercise test was perfomred to determine dynamic pulmonary variables. A MANCOVA, covarying for age, height, and fitness level showed significant differences in FVC (F(4,36)=5.55), FEV1 (F(4,36)=7.86), PEF (F(4,36)=6.44), MVV (F(4,36)=5.32), and VC (F(4,36)=4.14) between the HIV-1 seropositive and seronegative men at rest (p<0.05). During exercise, a MANCOVA, covarying for age and fitness level showed significant differences in dyspnea index (F(3,37)=4.48), O2 pulse (F(3,37)=7.77), dead space to tidal volume (F(3,37)=6.24), and ventilation (F(3,37)=9.86) between the two groups (p<0.01). This data suggests that HIV-1 infection compromises pulmonary function even in the early stages of HIV-1 disease, before the advent of overt pulmonary disease.