Release of Soluble Insulin Receptor From Neurons by Cerebrospinal Fluid From Patients With Neurocognitive Dysfunction and HIV Infection

Previously, we found that high levels of soluble insulin receptor (sIR) in the cerebrospinal fluid (CSF) of an HIV-infected women cohort were associated with the presence and severity of HIV-associated neurocognitive disorders (HAND). In this study we investigated if CSF from this population, HIV-1 Tat, and selected cytokines induces sIR secretion from human neuronal cells. Twenty-three (23) HIV-seropositive women stratified by cognitive status and five HIV- seronegative women were evaluated. Soluble IR levels were measured in the extracellular medium of neuronal cells (SH-SY5Y) that were exposed (for 24 h) to the CSF of patients. The levels of sIR, HIV-1 Tat, and cytokine levels (IL-2, IL4, IL-6, IFNγ, TNFα, and IL-10) were quantified in the CSF of participants by ELISA and flow cytometry. Neuronal secretion of sIR was measured after exposure (24 h) to HIV-1 Tat (0.5–250 nM), or specific cytokines. The effects of TNFα and HIV-1 Tat on sIR secretion were also evaluated in the presence of R7050 (TNFα antagonist; 10 nM). Neurons exposed to the CSF of HIV-infected women had higher sIR levels according to the severity of neurocognitive impairment of the participant. Increased CSF sIR levels were associated with the presence and severity of HAND and were positively correlated with CSF HIV-1 Tat levels in HIV-infected women with cognitive impairment. CSF levels of IL-2, IFNγ, and TNFα were significantly increased with HAND. However, only TNFα (5 pg/mL) and HIV-1 Tat (100 nM) induced a significant increase in neuronal sIR secretion after 24 h exposure, an effect that was antagonized when each were combined with R7050. Our data suggests that TNFα and HIV-1 Tat from the CSF of HIV-infected women may regulate the secretion of sIR from neuronal cells and that the effect of HIV-1 Tat on sIR secretion may depend on TNFα receptor activation

Soluble and Cell-Associated Insulin Receptor Dysfunction Correlates with Severity of HAND in HIV-Infected Women

Blood sugar metabolism abnormalities have been identified in HIV-infected individuals and associated with HIV-associated neurocognitive disorders (HAND). These abnormalities may occur as a result of chronic HIV infection, long-term use of combined antiretroviral treatment (CART), aging, genetic predisposition, or a combination of these factors, and may increase morbidity and mortality in this population.To determine if changes in soluble and cell-associated insulin receptor (IR) levels, IR substrate-1 (IRS-1) levels, and IRS-1 tyrosine phosphorylation are associated with the presence and severity of HAND in a cohort of HIV-seropositive women.This is a retrospective cross-sectional study using patient database information and stored samples from 34 HIV-seropositive women and 10 controls without history of diabetes from the Hispanic-Latino Longitudinal Cohort of Women. Soluble IR subunits [sIR, ectodomain (α) and full-length or intact (αβ)] were assayed in plasma and CSF samples by ELISA. Membrane IR levels, IRS-1 levels, and IRS-1 tyrosine phosphorylation were analyzed in CSF white cell pellets (WCP) using flow cytometry. HIV-seropositive women had significantly increased levels of intact or full-length sIR in plasma (p<0.001) and CSF (p<0.005) relative to controls. Stratified by HAND, increased levels of full-length sIR in plasma were associated with the presence (p<0.001) and severity (p<0.005) of HAND. A significant decrease in IRS-1 tyrosine-phosphorylation in the WCP was also associated with the presence (p<0.02) and severity (p<0.02) of HAND.This study provides evidence that IR secretion is increased in HIV-seropositive women, and increased IR secretion is associated with cognitive impairment in these women. Thus, IR dysfunction may have a role in the progression of HAND and could represent a biomarker for the presence and severity of HAND

Assessing health-related resiliency in HIV+ Latin women: Preliminary psychometric findings.

HIV-associated vulnerabilities-especially those linked to psychological issues-and limited mental health-treatment resources have the potential to adversely affect the health statuses of individuals. The concept of resilience has been introduced in the literature to shift the emphasis from vulnerability to protective factors. Resilience, however, is an evolving construct and is measured in various ways, though rarely among underserved, minority populations. Herein, we present the preliminary psychometric properties of a sample of HIV-seropositive Puerto Rican women, measured using a newly developed health-related resilience scale.The Resilience Scales for Children and Adolescents, an instrument with solid test construction properties, acted as a model in the development (in both English and Spanish) of the HRRS, providing the same dimensions and most of the same subscales. The present sample was nested within the Hispanic-Latino longitudinal cohort of women (HLLC), that is part of the NeuroAIDS Research Program at the University of Puerto Rico (UPR), Medical Sciences Campus (MSC). Forty-five consecutively recruited, HIV+ women from the HLLC completed a demographic survey, the HRRS, and the Beck Depression Inventory-I, Spanish version.The results demonstrate excellent overall internal consistency for the total HRRS score (α = 0.95). Each of the dimensional scores also evidenced acceptable internal consistency (α ≥ 0.88). All the dimensional and subscale content validity indices were above the 0.42 cut-off. Analysis revealed a significant negative correlation between the HRRS total score and BDI-I-S (r(45) = -0.453, p < 0.003).Albeit preliminary in nature, the present study provides support for the HRRS as a measure to assess resilience among individuals living with chronic medical conditions. Minority populations, especially non-English speaking ones, are understudied across the field of medicine, and when efforts are made to include these patient groups, measurement is rarely tailored to their unique cultural and linguistic experiences. The HRRS is a measure that addresses these notable voids in the medical literature

Soluble Insulin Receptor Levels (MFI) and HIV-seropositive women stratified by HAND.

a<p>MFI  =  Median Fluorescence Intensity; median (interquartile range [25^th and 75^th percentile]),</p>b<p>significant p value<0.05^*.</p

Soluble insulin receptor full-length (sIRαβ) stratified by HAND.

<p>Soluble insulin receptor (sIR) intact or full-length (αβ) subunit was measured by ELISA <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037358#pone.0037358-The1" target="_blank">[47]</a> in plasma (A) and CSF (B) of HIV-seropositive women (HIV+) (n = 34) stratified by HAND into normal cognition (n = 11), asymptomatic impairment (n = 8), and symptomatic impairment (n = 15); and 10 HIV-negative controls (HIV−) (5 plasma were different women from 5 CSF). In plasma (A), levels of full-length sIR were significantly increased from controls in all HIV-seropositive women and it correlated with the severity of HAND (normal cognition [p = 0.003], asymptomatic impairment [p<0.001], and symptomatic impairment [p<0.001]). Also, women with symptomatic impairment had significant higher levels of full-length sIR when compared to those with normal cognition (p = 0.009). A similar trend was observed in CSF samples (B), although the only significant increased was observed in the women with symptomatic impairment when compared to controls. (MFI = Median Fluorescence Intensity).</p

Membrane insulin receptor (mIR), insulin receptor substrate 1 (IRS-1), and IRS-1 tyrosine phosphorylation levels in the CSF white cell pellet (CSF WCP) stratified by HAND.

a<p>For the mIR (MFI) and IRS-1 we analyzed 11 women with normal cognition, 8 with asymptomatic impairment, and 15 with symptomatic impairment. For IRS-1 tyrosine phosphorylation 5 women per group were analyzed;</p>b<p>significant p value<0.05^*;</p>c<p>MFI = Median Fluorescence Intensity; median (interquartile range [25^th and 75^th percentile]).</p