Abnormal free fatty acids and cortisol concentrations in the serum of AIDS patients

Decreased Docosahexaenoic Acid Levels in Serum of HIV Carrier Patients

The study aimed to measure serum fatty acids (FAs) composition in HIV carrier patients and compare it with non-HIV carrier patients. The FAs composition was measured by gas chromatography as follows: four saturated FAs myristic acid (14:0), palmitic acid (16:0), stearic acid (18:0), and docosanoic acid (22:0); four monounsaturated FAs 7-hexadecenoic acid (16:1 n-9), palmitoleic acid (16:1 n-7), oleic acid (18:1 n-9), and vaccenic acid (18:1 n-7); and three polyunsaturated FAs linoleic acid (18:2 n-6), dihomo-γ-linolenic acid (20:3 n-6), and docosahexaenoic acid (DHA, 22:6 n-3). We reported herein lower (P < .05) DHA concentration (by 40%) in the serum of HIV carrier patients than in non-HIV carrier patients. This FA has a pivotal role as a precursor of anti-inflammatory molecules with beneficial effects on metabolism, cardiovascular system, and immunological system. Even though most clinical studies reported beneficial effects of DHA supplementation in HIV carrier patients, this issue remains under debate. Further investigations then require to fully clarify the role of DHA in preventing or alleviating the comorbidities associated with HIV infection.

Correlation of baseline hormonal disorders with immunological failure and mortality in male HIV patients during follow-up

To assess the effect that hormonal disturbances have on HIV prognosis in male patients. A prospective follow-up study was conducted among male HIV patients who started antiretroviral therapy (ART) between July 1, 2011 and June 30, 2014. The final follow-up session occurred before December 31, 2014. We examined the correlation between pre-ART hormone levels and disease prognosis. The Kaplan-Meier method and the multivariate Cox proportional hazard model were used to identify hormone-related predictors of immunological failure and mortality. During the follow-up of 163 male HIV patients, mortality rate occurred at a rate of 16.0% (26/163). Of these deaths, 84.6% (22/26) were acquired immunodeficiency syndrome-related. Furthermore, 53 patients were found to have suffered from immunological failure. Both pre-ART CD4+ T cell counts and the clinical stage assigned to the patients correlated strongly with dehydroepiandrosterone sulfate levels. Hyponatremia, high cortisol levels, tuberculosis, and being at World Health Organization (WHO)-defined clinical stage 4 were characteristics that associated significantly with mortality. Being at WHO clinical stage 4 was, itself, a factor that significantly associated with immunological failure. High cortisol levels were found to be an important hormonal disorder that associated with mortality. None of the hormones examined in this study had a strong correlation with immunological failure.

Altered lipid concentrations of liver, heart and plasma but not brain in HIV-1 transgenic rats

Disturbed lipid metabolism has been reported in antiretroviral-naive HIV-1-infected patients suggesting a direct effect of the virus on lipid metabolism. To test that the HIV-1 virus alone could alter lipid concentrations, we measured these concentrations in an HIV-1 transgenic (Tg) rat model of human HIV-1 infection, which demonstrates peripheral and central pathology by 7-9 months of age. Concentrations were measured in high-energy microwaved heart, brain and liver from 7-9 month-old HIV-1 Tg and wildtype rats, and in plasma from non-microwaved rats. Plasma triglycerides and liver cholesteryl ester and total cholesterol concentrations were significantly higher in HIV-1 Tg rats than controls. Heart and plasma fatty acid concentrations reflected concentration differences in liver, which showed higher n-3 and n-6 polyunsaturated fatty acid (PUFA) concentrations in multiple lipid compartments. Fatty acid concentrations were increased or decreased in heart and liver phospholipid subfractions. Brain fatty acid concentrations differed significantly between the groups for minor fatty acids such as linoleic acid and n-3 docosapentaenoic acid. The profound changes in heart, plasma and liver lipid concentrations suggest a direct effect of chronic exposure to the HIV-1 virus on peripheral lipid (including PUFA) metabolism.

Metabolic syndrome and serum fatty acid patterns in serum phospholipids in hypertriglyceridemic persons with human immunodeficiency virus

BACKGROUND

HIV infection and its treatment are associated with abnormal lipid profiles. High triglyceride concentrations and low HDL-cholesterol concentrations are the most common health abnormalities and raise concerns about an increased risk of cardiovascular disease.

OBJECTIVE

We compared the fatty acid patterns of serum phospholipids between persons with HIV and non-HIV controls to determine whether there are differences that explain the elevated triglyceride concentrations, insulin resistance, and inflammation that are part of the metabolic syndrome in patients with HIV.

DESIGN

Thirty-nine persons with HIV and elevated serum triglycerides (>150 mg/dL) and/or indicators of insulin resistance were recruited to examine fatty acid profiles in serum phospholipid fractions relative to those of 2 control groups without HIV (n = 31).

RESULTS

Higher concentrations of 16:1 and 18:0 fatty acids in the phospholipid fraction indicated increased lipogenesis in the HIV patients and in the non-HIV controls at risk of the metabolic syndrome. However, the subjects with HIV had higher concentrations of both n-6 (omega-6) and n-3 fatty acids of higher elongation and desaturation levels, which indicated a greater promotion of these pathways in this population. The nanomolar percentage (%nmol) arachidonic acid was the same in all 3 groups.

CONCLUSIONS

Persons with and without HIV, at risk of the metabolic syndrome, show indications of increased lipogenesis, more so in subjects with HIV taking medication. Higher proportions of distal elongation and desaturation fatty acid products were seen only in the phospholipids fatty acid fraction of the subjects with HIV.

Progressive dysregulation of autonomic and HPA axis functions in HIV-1 clade C infection in South India

Human immunodeficiency virus type 1 (HIV-1) infection causes a wide spectrum of abnormalities in neurological, neuropsychological, and neuroendocrinological functions. Several studies report disturbance in autonomic nervous system (ANS) and hypothalamic pituitary-adrenal (HPA) axis function in HIV-1B infected individuals. However, no such investigations on the effect of HIV-1 clade C infection, particularly during the initial phase of the disease progression, have been reported. The present investigations were carried out longitudinally over a 2-year period at 12 monthly intervals in clinically asymptomatic HIV-1 clade C seropositive patients (n=120) and seronegative control subjects (n=29). We determined both the basal levels and the dynamic changes in plasma levels of norepinephrine (NE), epinephrine (E), adrenocorticotrophic hormone (ACTH) and cortisol (CORT). Studies were also extended longitudinally (at three separate yearly visits of each participant), to evaluate the response of autonomic and HPA axis to mirror star tracing challenge test (MSTCT) and the values were determined as area under the curve (AUC, corrected for baseline levels of NE, E, ACTH, and CORT). The findings show that the values of basal plasma NE levels, as well as NE response to MSTCT (AUC) at the first visit of HIV-1 seropositive individuals did not differ from those found in the control subjects (NE, pg/ml, HIV-1C=313.5+/-12.7 vs. controls=353.0+/-21.3; p=NS; AUC, HIV-1C=225+/-14.75 vs. controls=232.7+/-19.34; p=NS, respectively). At the subsequent two visits of HIV-1 positive patients however, NE response to MSTCT challenge was progressively attenuated (AUC=235+/-19.5 and 162.7+/-13.6; p<0.01 and 0.05, respectively) compared to that found at the first visit. On the other hand, plasma levels of E as well as E response to MSTCT at the first visit were significantly lower in HIV-1C seropositive individuals compared to those in the control subjects (pg/ml, HIV-1C=77.30+/-5.7 vs. controls=119.1+10.5; p<0.05; AUC, HIV-1C =83.29+/-7.5 vs. controls=172.3+/-18.9; p<0.001), but no further change was observed in AUC of E in response to MSTCT at the two subsequent yearly visits. The basal plasma levels of ACTH in HIV-1C seropositives were not different than in the control subjects (pg/ml: HIV-1C=20.0+/-0.9 vs. controls=23.1+/-1.6; p=NS), but ACTH response to MSTCT in HIV-1C seropositive patients at the first visit was lower than in the controls (AUC, HIV-1C=23.57+/-1.5 vs. controls=30.94+/-3.5; p<0.05), and fluctuated between high and low at the second and third visits (AUC, 28.89+/-2.3 and 21.69+/-2.36, respectively). However, the baseline plasma levels of cortisol as well as the response of cortisol to MSTCT (AUC) in HIV-1C seropositive individuals were higher than in the control subjects at the first visit (mug/dl, HIV-1C=9.83+/-0.39 vs. controls=6.3+/-0.56; p<0.05; AUC, HIV-1C=12.31+/-0.7 vs. control=9.18+/-0.9; p<0.05), and remained high at the two subsequent yearly follow up visits of HIV-1C (AUC, 11.8+/-0.86 and 11.98+/-0.77, respectively). These findings demonstrate attenuated autonomic functions, a disconnection between response of ACTH and cortisol to the MSTCT challenge, and an inverse relationship between plasma levels of catecholamine(s) and cortisol. Since plasma catecholamines and cortisol are the peripheral mediators of the autonomic and HPA axis function, the findings of this study reflect the overall adverse effect of HIV-1C infection on autonomic as well as HPA axis functions. The findings, apart from being the first to demonstrate the progressive dysregulation of autonomic nervous system and HPA axis function among HIV-1C infected seropositive individuals much ahead of the onset of acquired immunodeficiency syndrome (AIDS), also suggest that MSTCT, involving visuoconstructive cognitive abilities, is an effective stressor for unraveling the underlying dysfunctions in the neuroendocrine functions in health and disease.

Longitudinal evolution of HIV-1-associated lipodystrophy is correlated to serum cortisol:DHEA ratio and IFN-alpha

BACKGROUND

We have previously shown that lipid alterations in HIV-1-associated lipodystrophy (LD) are correlated with decreased serum dehydroepiandosterone (DHEA) and increased cortisol:DHEA ratio and IFN-alpha levels.

OBJECTIVE

To evaluate in a longitudinal study whether steroid and cytokine modifications are associated with the evolution of physical changes and lipid alterations associated with LD.

METHODS

Thirty-four HIV-1-positive men were followed during 32.5 +/- 4.0 months and tested at four time-points. The patients were subdivided into five groups according to physical changes and anthropometric measurements: LD-negative, initially LD-negative becoming LD-positive, LD-positive unchanged, aggravated or improved. Serum lipids, apolipoproteins, adrenal steroids and cytokines were measured and compared with baseline values.

RESULTS

(1) LD aggravation is associated with persistent elevated lipids, a decrease in serum DHEA, an increase in cortisol:DHEA ratio and persistent high levels of IFN-alpha. (2) LD improvement is associated with normalization of serum lipids, an increase in serum DHEA leading to normalization in cortisol:DHEA ratio, and normalization of IFN-alpha levels. (3) In LD-positive men evolution of VLDL cholesterol is negatively correlated with DHEA (r = -0.56, P < 0.01) and positively with cortisol:DHEA ratio (r = 0.62, P < 0.004) and with IFN-alpha (r = 0.57, P < 0.01). (4) The switch to LD is associated with a decrease in serum DHEA. (5) Patients who remained LD-negative maintained normal lipids, elevated cortisol and DHEA, and normal cortisol:DHEA ratio and normal levels of IFN-alpha.

CONCLUSIONS

This study indicates that cortisol:DHEA ratio and serum IFN-alpha levels are closely associated with clinical evolution and atherogenic lipid alterations in LD.

Changes in cortisol/DHEA ratio in HIV-infected men are related to immunological and metabolic perturbations leading to malnutrition and lipodystrophy

HIV-1 infection is associated with immune deficiency and metabolic perturbations leading to malnutrition and lipodystrophy. Because immune response and metabolic perturbations (protein and lipid metabolism) are partly regulated by glucocorticoids and DHEA, we determined serum cortisol and DHEA concentrations, and the cortisol/DHEA ratio in HIV-positive men, either untreated or receiving various antiretroviral treatments (ART), including highly active antiretroviral therapy (HAART). Cortisol levels were found increased in all patients, whatever the stage of the disease and independently of the ART treatment. In contrast, serum DHEA was elevated in the asymptomatic stage, and it was below normal values in AIDS patients, either untreated or mono-ART-treated. The DHEA level was low in HAART-treated patients with lipodystrophy (LD+) and highly increased in HAART-treated patients without lipodystrophy (LD-). Consequently, the cortisol/DHEA ratio was similar to controls in asymptomatic untreated or mono-ART-treated patients, but increased in AIDS patients. Interestingly, this ratio was increased in LD+ HAART-treated men, but normalized in LD- HAART-treated patients. Changes in the cortisol/DHEA ratio were negatively correlated with the in vivo CD4 T-cell counts, with the malnutrition markers, such as body-cell mass and fat mass, and with the increased circulating lipids (cholesterol, triglycerides, and apolipoprotein B) associated to the lipodystrophy syndrome. Our observations show that the cortisol/DHEA ratio is dramatically altered in HIV-infected men, particularly during the syndromes of malnutrition and lipodystrophy, and this ratio remains elevated whatever the antiretroviral treatment, including HAART. These findings have practical clinical implications, since manipulation of this ratio could prevent metabolic (protein and lipid) perturbations.

Effects of protein-energy malnutrition and human immunodeficiency virus-1 infection on essential fatty acid metabolism in children

This report summarizes data on the availability of essential fatty acids (EFAs) and their long-chain polyunsaturated fatty acid (LCPUFA) metabolites in protein-energy malnutrition (PEM), in human immunodeficiency virus-1 (HIV-1) infection for which less information is available, and the combination of both PEM and HIV-1. The contribution of different EFAs and LCPUFAs to the fatty-acid composition of plasma and erythrocyte membrane lipids was found to be reduced in children with PEM in comparison with well-nourished children. In addition to limited dietary EFA supply, reduced bioconversion of EFAs to their respective LCPUFA metabolites and/or peroxidative degradation of LCPUFAs may contribute to the reduction of LCPUFA status in malnourished children. Restoration of normal energy, protein, and EFA intakes does not appear to readily correct abnormalities of plasma and erythrocyte membrane LCPUFA values. Enhanced dietary supply of LCPUFAs and/or improved supply of antioxidant vitamins may represent novel therapeutic modalities in severe PEM. With and without PEM, HIV infection was related to altered availability of various EFAs and LCPUFAs in HIV-seropositive children. The plasma total lipid fatty-acid profiles seen in well-nourished children with HIV infection were compatible with an HIV infection-related enhancement of the metabolic activity of the conversion of EFAs to their respective LCPUFA metabolites. However, the plasma phospholipid EFA and LCPUFA profiles seen in severely malnourished children with HIV infection more closely resembled those seen in children with PEM but without HIV infection than in those in children with HIV infection but no PEM. Metabolic studies using stable isotope-labeled fatty acids may contribute to better understanding of the HIV-related changes in EFA metabolism and clearly are needed before therapeutic conclusions can be drawn.

Correlation between increased cortisol:DHEA ratio and malnutrition in HIV-positive men

Malnutrition in HIV-infected patients is characterized by a loss of both fat-free mass (FFM) and fat mass (FM). Glucocorticoids and androgens change during the course of the infection and may play a key role in the protein balance. The serum concentrations of cortisol, adrenal (DHEA and DHEA sulfate) and gonadal androgens (androstenedione, testosterone, and dihydrotestosterone) of HIV-positive men were measured and compared with several parameters of body composition as a function of body weight loss (BWL). The patients were assigned to one of five groups according to their BWL: group I (controls, n = 10) < 5%, group II (n = 7) 5-10%, group III (n = 8) 10.1-16%, group IV (n = 9) 16.1-24%, and group V (n = 4) > 24.1%. Correlation analysis showed significant positive or negative relationships between several markers of malnutrition and adrenal androgens and the cortisol:DHEA ratio, but not with cortisol. BWL was negatively correlated with DHEA (r = -0.69, P < 0.0001), DHEA sulfate (r = -0.58, P < 0.0001) and testosterone (r = -0.34, P < 0.03), but positively with the cortisol:DHEA ratio (r = 0.61, P < 0.0001). In contrast, BCM was positively correlated with DHEA (r = 0.34, P < 0.04) and DHEA sulfate (r = 0.36, P < 0.03) and negatively with the cortisol:DHEA ratio (r = -0.58, P < 0.0001). The cortisol:DHEA ratio was also negatively correlated with BMI (body mass index) (r = -0.56, P < 0.01), fat-free mass (r = -0.48, P < 0.004), fat mass (r = -0.39, P < 0.02), and BCM:weight ratio (r = -0.47, P < 0.005) and positively with the extracellular:intracellular water ratio (r = 0.54, P < 0.001). These data indicate that the steroid hormone environment of patients, particularly their cortisol:DHEA ratio, is linked to the malnutrition associated with HIV infection. The decreased DHEA and increased cortisol in patients with the advanced stages of disease could be associated with increased protein catabolism.

Glutathione homeostasis is disturbed in CD4-positive lymphocytes of HIV-seropositive individuals

BACKGROUND

Numerous in vitro tests have suggested that a disturbed cellular glutathione homeostasis plays an important role in the pathogenesis of human immunodeficiency virus (HIV) infection.

METHODS

Using validated high-performance liquid chromatography (HPLC) methods, glutathione concentrations were determined in plasma and in cytosol of CD4+ lymphocytes and CD14+ cells of HIV-seropositive individuals and healthy control subjects. We measured concentrations of total glutathione, which is the sum of reduced (GSH) and oxidised (GSSG) glutathione and mixed disulphides of which there are two fractions: soluble mixed disulphides (GSSR) and protein bound glutathione (ProSSG). Also, non-protein-bound glutathione was measured, which is the sum of GSH, GSSG and GSSR. Thirty-five healthy control subjects and 35 HIV-infected individuals participated in the study.

RESULTS

We found that in CD4+ lymphocytes from HIV-seropositive individuals, total glutathione levels were significantly higher than in healthy control subjects, whereas the fraction of non-protein-bound glutathione was not different. This can only be explained by an increase in the protein-bound fraction of glutathione indicating the presence of oxidative stress in CD4+ lymphocytes of HIV-seropositive individuals. Glutathione measurements of cytosol of CD14+ cells and plasma were, however, not compatible with significant increased oxidation. Glutathione precursors (cysteine, cysteinylglycine, glutamylcysteine and homocysteine) and products of lipid peroxidation (thiobarbituric acid-reactive substances) were also measured in plasma and did not differ between healthy control subjects and HIV-seropositive individuals.

CONCLUSION

We conclude that the glutathione homeostasis is disturbed in CD4+ lymphocytes of HIV-seropositive individuals. The glutathione redox dysbalance in CD4+ lymphocytes could be important in the pathogenesis of HIV infection and have implications for therapy.

Low levels of linoleic acid in plasma total lipids of HIV-1 seropositive children

OBJECTIVE

To assess the plasma fatty acid status of a group of well-nourished children with the human immunodeficiency virus type-1 (HIV-1) and how this relates to the blood total CD4+ lymphocyte count.

SUBJECTS

Fourteen HIV-1 seropositive children at various stages of disease and with adequate growth indices were assessed and compared to a control group of 30 healthy children.

RESULTS

The concentrations (mg/dL) of plasma total fatty acids were not different between the two groups. HIV-1 seropositive children presented lower levels of 18-C essential polyunsaturated fatty acids (PUFA: linoleic acid, LA, and alpha-linolenic acid) and higher levels of their 20-C long-chain derivatives (di-homo-gamma-linolenic acid, arachidonic acid, AA, and eicosapentaenoic acid) and docosahexaenoic acid in their plasma total lipids. The lowest plasma LA levels were observed in the subgroup of patients with more advanced stages of disease. In bivariate analyses the plasma LA levels related positively (Spearman r = 0.50, p = 0.06), while the LA/AA ratio related negatively (Spearman r = -0.51, p = 0.06), to the total CD4+ count.

CONCLUSIONS

Childhood HIV-1 infection is associated with changes in plasma fatty acid profile suggestive of an increased PUFA turnover. Decreased levels of LA (together with higher plasma AA levels) appear to be associated with more advanced clinical and biochemical stages of disease.

Postprandial free fatty acids stimulate activity of human corticosteroid binding globulin

The effect of postprandial variation of free fatty acids (FFA) on serum corticosteroid binding globulin (CBG) properties and cortisol (hydrocortisone) concentrations were explored in 11 women (20-30 yr) during 8 h after an oral load of tallow (26% C16:0, 18% C18:0, and 43% C18:1), oleic-sunflower (oleic-SF; 73% C18:1), sunflower (SF; 67% C18:2), and mixed oil (MO; 39% C18:1 and 48% C18:2). Serum FFA increased little after SF and MO but more than doubled in the late postprandial period (6 and 8 h) after oleic-SF (due to monounsaturated FFA) or tallow (due to saturated and monounsaturated FFA). CBG concentrations remained unchanged, but in relation with the postprandial elevation of serum FFA, CBG binding activity was increased after tallow or oleic-SF as a result of a combined two- to threefold increase in affinity constant and a 50% reduction in binding sites. Immunological and in vitro binding studies showed the changes in CBG behavior to be conformational and to be mediated mainly by monounsaturated FFA, especially C18:1. The modifications of CBG properties were associated with sustained high concentrations of cortisol (suppression of midday decrease) 6 and 8 h after tallow or oleic-SF. Thus dietary FFA may have an impact on bioavailability of glucocorticoids.

Fatty acids and plasma antioxidants in HIV-positive patients: correlation with nutritional and immunological status

OBJECTIVE

To investigate red blood cell (RBC) and plasma fatty acids (FA) in HIV-positive patients in relation to oxidative stress and nutritional or immunological status.

DESIGN AND METHODS

FA, plasma selenium, vitamins A and E were measured in 95 patients divided into four groups according to CD4 cells.

RESULTS

Poly- and di-unsaturated FA (PUFA, DUFA) decreased and saturated FA (SFA) increased in RBC in the patients below 400/mm3 and in plasma in the patients below 50/mm3. RBC SFA correlated to CD4 cells, PUFA to MDA. Unlike vitamin E, plasma vitamin A and selenium decreased in most groups. Plasma SFA and MUFA correlated negatively to selenium and PUFA and DUFA to vitamin E. No correlation was found between PUFA and nutritional markers.

CONCLUSION

FA seem to be modified during HIV infection by oxidative stress and disease evolution, but not by denutrition.

Differences in androgens of HIV positive patients with and without Kaposi sarcoma

AIM

Since most forms of Kaposi sarcoma are much more common in men than in women, the aim of this study was to examine serum concentrations of sex steroids in HIV positive men with and without Kaposi sarcoma.

METHODS

Blood samples from 34 HIV positive men without Kaposi sarcoma (KS-) and 28 with Kaposi sarcoma (KS+) and from 35 HIV negative men (controls) were analysed for adrenal and gonadal steroids. Further analysis was done in subgroups classified by CD4 lymphocyte counts.

RESULTS

KS+ patients had significantly higher serum dehydroepiandrosterone (DHEA) and testosterone concentrations than the KS- patients, and their DHEA, DHEA sulphate, testosterone, and androstenedione values were higher than in the controls. The KS+ patients with more than 500 CD4 lymphocytes per mm3 had significantly higher serum DHEA, DHEA sulphate, and testosterone than the KS- patients with the same CD4 counts; those with 500-200 CD4 cells/mm3 had higher serum DHEA and testosterone than the equivalent KS- men; and those with < 200 CD4 cells/mm3 had raised DHEA only compared with KS- men. Both KS+ and KS- men had higher serum progesterone and oestradiol than the controls. Glucocorticoids were not significantly altered.

CONCLUSIONS

The high androgen levels in KS+ patients, particularly in the early stages of the disease (> 500 CD4 cells/mm3), may affect the immune system by inducing an abnormal cytokine profile, or by increasing T8 proliferation and activation, or both. This raises the question of the relationship between androgens and Kaposi sarcoma.

Phospholipid metabolism of lymphocytes with inhibited glutathione synthesis using L-buthionine-S,R-sulfoximine

The potential role of phospholipid metabolism in restricting lymphocyte proliferation under conditions of oxidative stress was investigated using [1-14C]-arachidonic acid (14C-AA) and 32P-orthophosphoric acid. Human peripheral blood lymphocytes (PBL) and PBL depleted of glutathione with L-buthionine-S,R-sulfoximine (BSO-PBL) were compared. The relative uniformity of glutathione depletion in the PBL population was assessed by flow cytometry. BSO-PBL were 40 to 90% depleted of glutathione 1 to 3 days after activation, respectively, and the BSO-PBL had unimpaired early activation events based on 32P-phosphatidylinositol levels. However, unlike stimulated PBL, which showed a progressive decrease in radioactivity incorporated into phosphatidylcholine and a corresponding increase into phosphatidylethanolamine, no significant differences occurred with BSO-PBL. Prelabeled BSO-PBL showed considerably more 14C radioactivity in the supernatant following 72-120 h stimulation with anti-CD3 than control PBL, which was mostly in the form of unmetabolized 14C-AA. Higher levels of leukotriene B4, 5-hydroxyeicosatetraenoate and 12-hydroxy-5,8,10-heptadecatrienoate also were observed with L-buthionine-S,R-sulfoximine treatment, which could explain the impaired proliferation obtained with a depletion of cellular glutathione. Both lysophosphatidylcholine and liberated free 14C-AA increased with L-buthionine-S,R-sulfoximine treatment following 72 h stimulation, suggesting functional impairment in the reacylating enzymes. The increased release of 14C-AA by BSO-PBL also may contribute to the imparied proliferation that occurs with loss of glutathione.

Glucocorticoids and the immune system in AIDS

Data reported in the literature show in the majority of cases an increased basal cortisol level in HIV-positive patients compared with controls, although the plasma concentration of cortisol in HIV-positive patients is generally within the physiological range. It is well known that pharmacological doses of glucocorticoids are immunosuppressive, but little is known about the effects of physiological concentrations of cortisol on the immune system. If a dialogue really exists between the HPA axis and the immune system, immune responses should be modulated by physiological concentrations of cortisol, as well as pathological levels of cortisol (high as in Cushing's syndrome or low as in Addison's disease), which are known to be associated with impaired immune system responses. We suggest that in HIV-positive patients, a chronic increase in the basal endogenous cortisol levels may provoke an imbalance in cytokine production, with a decrease in the production of type 1 and an increase in that of type 2. The type 1 to type 2 shift might be synergic with the increased cortisol levels in enhancing viral replication and apoptotic phenomena, and finally in causing the progression of HIV infection.

Perturbation of the immunosuppressive action of glucocorticoids in rat thymocytes by liposoluble extracts of serum from AIDS patients

Liposoluble extracts of serum from healthy men and AIDS patients (stages IVC1 and IVD by CDC criteria) inhibited the incorporation of [3H]thymidine into isolated rat thymocytes, but AIDS extracts were less inhibitory, requiring 1.8 times more cortisol in the AIDS extracts than in the healthy extracts to inhibit [3H]thymidine incorporation by 50%. Although the total serum extracts from AIDS patients contained 1.7 times more cortisol than the extracts from healthy controls, the AIDS extracts decreased the binding affinity (Ka) of [3H]dexamethasone to rat thymus glucocorticoid receptors by 50% less than the healthy control extracts. The present study seems to indicate that a substance(s) can be extracted from the serum of AIDS patients that attenuates the inhibitory effect of cortisol on thymocyte proliferation and interferes with the binding of cortisol to the glucocorticoid receptor.

The esterified plasma fatty acid profile is altered in early HIV-1 infection

Previous studies have shown that alterations in micronutrient utilization occur in patients with Acquired Immune Deficiency Syndrome. In this study, total plasma fatty acid composition was measured in 36 homosexual men infected with the Human Immunodeficiency Virus 1 (HIV-1) and in 17 HIV-1 seronegative homosexual men in order to evaluate differences associated with early HIV-1 infection. Immunologic assessment included CD4 cell number count and lymphocyte blastogenesis in response to the mitogens phytohemagglutinin (PHA) and pokeweed (PWM). The mean total amount of omega 6 polyunsaturated fatty acids (18:2 and 20:4) was significantly lower in the HIV-1 seropositive subjects (38 +/- 8.1% SD) as compared to HIV-1 seronegative subjects (43 +/- 4.2%; P = 0.0027). This was also reflected in a higher level of total saturated fatty acids (16:0 and 18:0) in HIV-1 seropositive subjects (30 +/- 2.2% vs. 26 +/- 2.8%; P = 0.0001). The ratio of linoleic to arachidonic acid (18:2 to 20:4) was higher in the HIV-1 seropositive group (6.76 +/- 4.88) compared to the HIV-1 seronegative group (4.86 +/- 1.37; P = 0.0213). The response to PHA in seropositive subjects correlated inversely with total plasma omega 6 fatty acids (r = -0.36; P = 0.027), and directly with the 18:2 to 20:4 ratio (r = 0.33; P = 0.046). CD4 cell counts and the response to PWM did not correlate with plasma fatty acid levels in HIV-1 seropositive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Modulation of glucocorticoid binding to rat liver cytosol receptor by lipid-soluble extracts from the serum of AIDS patients

The total liposoluble extract of sera from AIDS patients, IVC1 and IVD stages, containing cortisol and free fatty acids (FFA) inhibited [3H]dexamethasone binding to a lesser extent than did the same quantity of total liposoluble extract of sera from healthy men. FFA isolated from extracts of AIDS sera by Sephadex LH20 chromatography had less effect on [3H]dexamethasone binding to rat liver glucocorticoid receptor than those extracted from sera of healthy men. These results suggest the presence in sera of AIDS patients of a liposoluble substance which could be limiting the inhibitory effect of FFA on [3H]dexamethasone binding to glucocorticoid receptor by inducing a conformational change in glucocorticoid receptor that could alter the biological action of glucocorticoids. The pathological consequence could be the apparent contradiction of high cortisolemia and clinical symptoms of adrenal insufficiency that have been observed in AIDS patients.

Alterations in the concentrations and binding properties of sex steroid binding protein and corticosteroid-binding globulin in HIV+patients

The abnormal concentrations of steroid hormones and free fatty acids in the plasma of HIV-infected subjects are associated with qualitative and quantitative alterations in two of the major steroid hormones carrier proteins, sex steroid-binding protein (SBP) and corticosteroid-binding globulin (CBG). The properties of SBP and CBG in the sera of two age-matched groups of 67 men healthy blood donors (controls) and 64 HIV+subjects: 11 CDC group II and III (ASY), 6 CDC group IVA and 47 groups IV C1+D (AIDS) were analyzed. The HIV+patients had SBP concentrations 39-51% above those of controls. The sera of AIDS patients had higher SBP association constants (Ka) for testosterone than did those of the II, III and IVA groups and controls. In contrast, the CBG concentrations in all the HIV+subjects were similar to those of the controls. However, the binding properties of HIV+CBG were abnormal: the Ka's for cortisol and 17 alpha hydroxyprogesterone binding were 50% below normal, while the number of binding sites was significantly higher. Such changes in these carrier proteins could result from conformational transitions; they may cause abnormal transfer of hormonal information and/or steroid hormones metabolism, thus modifying the impact of steroids on the immune response in HIV+subjects.

Characterization of a major development-regulated serum thyroxine-binding globulin in the euthyroid mouse

We confirm our finding of a major development-regulated thyroxine-binding globulin (TBG) in the serum of the euthyroid mouse and investigate a number of its binding, structural and regulatory properties. Between 16 days foetal and 60 days postnatal life, the thyroxine (T4)- and tri-iodothyronine (T3)-binding activities of the sera show a striking ontogenic pattern: the binding is 2-3 times higher in foetuses than in mothers, then further increases after birth, reaching between 3 and 5 days maximum values which are 7-8 times higher than the adult ones. This pattern is not correlated with the ontogenesis of the acknowledged specific (transthyretin, TTR) and non-specific (albumin, alpha 1-foetoprotein) thyroid-hormone carriers of the mouse sera. PAGE studies demonstrate that the protein responsible for the elevated binding of the perinatal period is an alpha 1-globulin, with a migration similar to that of human and rat TBGs. Scatchard analysis is consistent with the notions that the T4-binding sites of TBG have high association constants, about two orders of magnitude above the T4 sites of TTR (10(9) M-1 as against 10(7) M-1) and low capacities (37 and 4 nmol/g of serum proteins in pups and adults respectively). Isoelectric focusing (i.e.f.) demonstrates that mouse TBG is a microheterogeneous protein separable, as a function of the pH gradient, in up to 10-12 isoforms, Marked shifts of the relative abundance of isoforms in the course of development are evidenced. The modulation of the TBG binding activity by non-esterified fatty acids (NEFA) and the control of its synthesis by the thyroid status are also reported. Mono- and poly-unsaturated NEFAs are strong inhibitors of the TBG, although they affect TTR less readily. On the other hand, the biosynthesis and/or secretion of TBG, but not of TTR, is under thyroid-hormone control, experimental hypothyroidism inducing a marked increase of the serum TBG. The TBG of mouse behaves as a highly significant parameter of development, pointing to a likely important function of the protein in the process of maturation. Our finding of major TBGs in both euthyroid rats and mice suggests that TBG is more widely spread than was thought until now, but difficult to detect in certain species outside definite maturation stages.

Conformational changes in rodent and human alpha-fetoprotein: influence of fatty acids

Binding, spectral and immunological studies were performed to demonstrate the conformational changes in rodent and human alpha-fetoprotein (AFP) induced by a free fatty acid environment. Scatchard analysis of estradiol (E2) binding to purified rat AFP indicated that unsaturated fatty acids changed the number of binding E2 sites and the apparent E2 equilibrium dissociation constant which varied non-linearly with docosahexaenoic acid concentration. UV spectral analysis of rodent and human AFPs showed that the absorbance minimum of AFP incubated with unsaturated fatty acid (L-AFP) was red-shifted, broadened and less pronounced than that of purified native AFP (N-AFP). Immunochemical studies with specific polyclonal antibodies to purified rodent and human AFPs (N-AFP antibodies) showed that these proteins lost immunoreactivity after incubation with unsaturated fatty acid. N-AFP antibodies recognized fewer epitopes on L-AFP than on N-AFP, whatever the species. Specific anti-rat L-AFP antibodies were used to demonstrate specific epitopes on rat L-AFP. Rat L-AFP antibodies did not recognize rat N-AFP. Saturated fatty acids were without effect on the binding, spectral and immunological properties of rodent and human AFPs. RIA or ELISA values for human AFP from fetal serum, hepatoma serum, and cord serum, were reduced 80, 50 and 5%, respectively, by unsaturated fatty acids. This decrease correlated with the relative percentage of polyunsaturated fatty acid in each biological fluid. Such results indicate that an unsaturated fatty acid environment induces conformational changes in AFP which may modulate the endocrine and immune functions of this protein.

The effect of fatty acids on the vulnerability of lymphocytes to cortisol

We have shown previously that cortisol-sensitive lymphocytes (thymocytes) have a much lower capacity than cortisol-resistant cells to catabolize cortisol and that linoleic acid inhibits the catabolism of cortisol by lymphocytes and modulates the sensitivity of lymphocytes to cortisol. In the present study, we attempted to see whether other fatty acids are inhibitory and if inhibition of cortisol catabolism by lymphocytes indicates a change in resistance of the cells to cortisol. Measuring the effect of fatty acids on cortisol catabolism by lymphocytes indicated that the polyunsaturated fatty acids, linoleate, arachidonate, and eicosapentaenoic, inhibit cortisol catabolism by lymphocytes. Using prostaglandin PGE2 and indomethacin as a blocker of prostaglandin formation, we observed that the effect of the polyunsaturated fatty acids was not due to the formation of prostaglandins. Examining the effect of fatty acids on the vulnerability of lymphocytes to cortisol, we noted that saturated fatty acids had no significant effect, whereas the aforementioned polyunsaturated fatty acids make lymphocytes more sensitive to cortisol.