Effects of folate deficiency and sex on carcinogenesis in a mouse model of oral cancer

OBJECTIVES

To investigate the effects of dietary folate and sex on histopathology of oral squamous cell carcinoma in mice.

MATERIALS AND METHODS

Mice (C57Bl/6, 30/sex) were fed either a deficient folate or sufficient folate diet. Vehicle or 4-nitroquinoline1-oxide (50 μg/mL) in vehicle were administered in drinking water for 20 weeks, followed by 6 weeks of regular drinking water. Oral lesions were observed weekly. Tongues were studied for histopathologic changes. Immunohistochemical techniques were used to measure cell proliferation (Ki67+), and to quantify expression of folate receptor, reduced folate carrier, and proton-coupled folate transporter. T cells, macrophages, and neutrophils were counted and normalized to area.

RESULTS

All 4NQO-treated mice developed oral tumors. Dietary folate level did not affect tumor burden. More tumors were observed on the ventral aspect of the tongue than in other locations within the oral cavity. 4-nitroquinoline-1-oxide-treated mice displayed 27%-46% significantly lower expression of all three folate transport proteins; diet and sex had no effect on folate transporter expression. T-cell and neutrophil infiltration in tongues were 9.1-fold and 18.1-fold increased in the 4-nitroquinoline-1-oxide-treated mouse tongues than in controls.

CONCLUSION

Treatment with 4NQO was the primary factor in determining cancer development, decreased folate transport expression, and lymphoid cell infiltration.

Fat and exposure to 4-nitroquinoline-1-oxide causes histologic and inflammatory changes in murine livers

Risk factors for liver cancer include tobacco use, alcohol consumption, obesity, and male sex. Administration of 4-nitroquinonline-1-oxide (4NQO) in drinking water mimics the effects of tobacco and leads to oral carcinoma in mice. This study compared the effects of diets high and low in saturated fat (HF and LF, respectively), and sex, on liver histopathology in 4NQO-treated mice and controls. We hypothesized that 4NQO would cause histopathological changes in liver, and that a HF diet would increase hepatic pathology when compared to the LF diet. Mice (C57Bl/6, 36/sex), were divided into a low fat (10 kcal% fat; LF) or high fat (60 kcal% fat, HF) diet. Mice were further subdivided into one of 3 water treatment groups for 17 weeks: water (control), vehicle (1.25% propylene glycol in water [PG]), or 4NQO in (50 μg/ml; 4NQO). All mice were subsequently given water alone for 6 more weeks. Upon euthanasia, livers were harvested, fixed, sectioned, and stained with hematoxylin and eosin (H&E). H&E slides were graded for histopathology; frozen liver samples were analyzed for triglyceride content. Trichrome stained sections were graded for fibrosis. CD3+ T cells, CD68+ macrophages, and Ly6+ neutrophils were detected by immunohistochemistry. Compared to water controls, 4NQO-treatment caused mouse liver histopathological changes such as fibrosis, and increases in hepatic neutrophils, T cells, and macrophages. HF diet exacerbated pathological changes compared to LF diet. Male controls, but not females, demonstrated severe steatosis and increased triglyceride content. 4NQO treatment decreased hepatic fat accumulation, even in animals on a HF diet. In conclusion, this murine model of oral cancer may serve as a model to study the effects of tobacco and diet on liver.

Dietary folic acid deficiency impacts hippocampal morphology and cortical acetylcholine metabolism in adult male and female mice

OBJECTIVE

One-carbon (1C) metabolism is a metabolic network that integrates nutritional signals with biosynthesis, redox homeostasis, and epigenetics. There are sex differences in hepatic 1C metabolism, however, it is unclear whether sex differences in 1C impact the brain. The aim of this study was to investigate if sex modulates the effects of dietary folic acid deficiency, the main component of 1C, in brain tissue using a mouse model.

METHODS

Male and female C57Bl/6J mice were placed on a folic acid deficient (FD) or control diet (CD) at six weeks until six months of aged. After which brain tissue and serum were collected for analysis. In brain tissue, hippocampal volume, morphology, and apoptosis as well as cortical acetylcholine metabolism were measured.

RESULTS

Male and female FD mice had reduced serum levels of folate. Both males and females maintained on a FD showed a decrease in the thickness of the hippocampal CA1-CA3 region. Interestingly, there was a sex difference in the levels of active caspase-3 within the CA3 region of the hippocampus. In cortical tissue, there were increased levels of neuronal ChAT and reduced levels of AChE in FD females and male mice.

CONCLUSIONS

The results indicated that FD impacts hippocampal morphology and cortical neuronal acetylcholine metabolism. The data from our study indicate that there was only one sex difference and that was in hippocampal apoptosis. Our study provides little evidence that sex modulates the effects of dietary folate deficiency on hippocampal morphology and cortical neuronal acetylcholine metabolism.

Dynamic Environmental Physical Cues Activate Mechanosensitive Responses in the Repair Schwann Cell Phenotype

Schwann cells plastically change in response to nerve injury to become a newly reconfigured repair phenotype. This cell is equipped to sense and interact with the evolving and unusual physical conditions characterizing the injured nerve environment and activate intracellular adaptive reprogramming as a consequence of external stimuli. Summarizing the literature contributions on this matter, this review is aimed at highlighting the importance of the environmental cues of the regenerating nerve as key factors to induce morphological and functional changes in the Schwann cell population. We identified four different microenvironments characterized by physical cues the Schwann cells sense via interposition of the extracellular matrix. We discussed how the physical cues of the microenvironment initiate changes in Schwann cell behavior, from wrapping the axon to becoming a multifunctional denervated repair cell and back to reestablishing contact with regenerated axons.

Dietary fat and male sex increase histopathological changes in a mouse model of oral cancer

OBJECTIVE

To compare the effects of dietary fat and sex on murine oral squamous cell carcinoma pathology.

MATERIALS AND METHODS

Male and female C57Bl/6 mice (36/sex) received a low-fat (10 kcal%) or high-fat (60 kcal%) diet. Water (control), vehicle, or 4-nitroquinoline-1-oxide in vehicle (50 μg/ml) was provided for 17 weeks followed by six additional weeks of water. Oral lesion development was recorded weekly. Histopathologic changes in tongues were examined, and T cells (CD3+), macrophages (CD68+), and neutrophils (Ly6+) were quantified.

RESULTS

All 4-nitroquinoline-1-oxide-treated mice developed oral tumors. High-fat diet exacerbated pathology, demonstrated by an increased final tumor burden (10.9 ± 4.5 vs. 7.9 ± 2.5, mm/mouse, p < .05; high-fat diet vs. low-fat diet, respectively), and a greater histopathology score. When dietary groups were combined, 4-nitroquinoline-1-oxide-treated males displayed higher histopathology scores than females (4.2 ± 0.3 vs. 3.6 ± 0.2, respectively, p < .05). Lymphoid cell infiltration was greater in the 4-nitroquinoline-1-oxide mouse tongues than controls: T cells (14.0 vs. 0.96 cells/mm² ), macrophages (3.6 vs. 1.8 cells/mm² ), and neutrophils (12.0 vs. 0.38 cells/mm² ).

CONCLUSION

High-fat diet and male sex increased the pathology of 4-nitroquinoline-1-oxide-induced oral cancer. Elevated lymphoid cell infiltration contributed to disease pathology.

Decreased expression of folate transport proteins in oral cancer

OBJECTIVES

The purpose of this study was to assess the expression of the 3 major folate transporters-folate receptors (FRs), reduced folate carrier (RFC), and proton-coupled folate transporter (PCFT)-in oral squamous cell carcinoma (OSCC). We hypothesized that patterns of expression of folate transporters would be different in OSCC compared with normal oral epithelium.

STUDY DESIGN

We used immunohistochemistry to examine the expression of FR, RFC, and PCFT in 15 primary specimens collected from patients with OSCC, 2 human cadaveric samples of OSCC, and 12 normal human cadaveric oral tissues from a medical gross anatomy laboratory. Possible correlations between the expression of each folate transporter and patients' clinical data were determined.

RESULTS

All 3 folate transporters were highly expressed in normal oral epithelium. In contrast, OSCC samples generally demonstrated low expression of FR, RFC, and PCFT, with wide distribution in the invading cancer cells. There were no differences in folate transporter expression between OSCC samples collected from patients and from human cadavers. The lowest expression of FR and PCFT characterized less-differentiated tumors, and the lowest expression of RFC correlated with higher lymph node involvement.

CONCLUSIONS

Human oral cancer samples expressed decreased amounts of all 3 major folate transport proteins compared with controls from normal cadaveric oral tissues.

Changes in inflammatory biomarkers after successful lifestyle intervention in obese children

BACKGROUND

Obesity has been associated with low-grade systemic inflammation, potentially leading to insulin resistance, type 2 diabetes, dyslipidemia, and cardiovascular diseases. Even moderate weight loss through dietary changes and physical exercise is effective in preventing and managing obesity-associated disorders. The aim of this study was to determine the effect of weight loss in response to a lifestyle modification on the serum levels of inflammatory markers in obese children and adolescents.

MATERIAL AND METHODS

Fifty obese subjects completed a six-month programme consisting of combined hypocaloric diet and moderate physical activity. High-sensitive C-reactive protein (CRP), interleukin-6 (IL-6), fibrinogen (FB), white blood count (WBC), glucose, insulin, insulin resistance index (HOMA IR), glycosylated haemoglobin (HbA(1c)), lipids as well as systolic (SBP) and diastolic blood pressure (DBP) were measured before and after intervention.

RESULTS

Patients had a 5.3 ± 3.4 kg average weight loss, with significant decreases of SDS-BMI, percentage of body fat, SDS-waist, SBP and DBP, HOMA-IR, HbA(1c) and reductions in serum IL-6, CRP, WBC, FB. In the multivariable linear models, changes in percentage of body fat and HOMA-IR were positively associated with favourable changes in inflammatory parameters.

CONCLUSION

This study demonstrates that weight reduction after successful lifestyle intervention results in improvements of blood inflammatory markers in obese children and adolescents.

Serum 25-hydroxyvitamin D (25-OH-D) in obese adolescents

BACKGROUND

There is increasing evidence that vitamin D deficiency is common and has been associated with several non-bone related outcomes, including insulin resistance, type 2 diabetes and cardiovascular disease. The influences of gender, puberty, and adiposity on serum hydroxyvitamin D (25-OH-D) levels and the relationship between 25-OH-D and insulin resistance in obese children were studied.

MATERIAL AND METHODS

Age, gender, pubertal stage, weight status (standard deviation score of body mass index: BMI-SDS, percentage body fat, waist circumference), 25-OH-D levels, and insulin resistance index calculated by homeostasis model assessment (HOMA-IR) were evaluated in 64 obese adolescents. Multivariable linear regression was used to determine factors associated with decreased serum 25-OH-D levels and to study the relationship between 25-OH-D and HOMA-IR.

RESULTS

Median serum 25-OH-D level was 10.1 ng/mL (25.2 nmol/L). 14% of patients were vitamin D-sufficient (25-OH-D ≥ 20 ng/mL), 36% had intermediate values (11-19 ng/mL), and 50% were deficient (25-OH-D ≤ 10 ng/mL). In the multivariable model, older age, puberty, higher value of percentage of body fat, and the presence of acanthosis nigricans (AN) were all negatively associated with 25-OH-D. Lower 25-OH-D levels were also associated with higher blood glucose, insulin and HOMA-IR after adjustment for puberty and SDS-BMI. Summer positively correlated with 25-OH-D level.

CONCLUSION

Our study confirms that obesity is a risk factor for vitamin D deficiency. Hypovitaminosis D, common in obese adolescents at risk for type 2 diabetes (older age, puberty, acanthosis nigricans) is associated with worse insulin resistance.

Exposure-dependent effects of ethanol on the innate immune system

Extensive evidence indicates that ethanol (alcohol) has immunomodulatory properties. Many of its effects on innate immune response are dose dependent, with acute or moderate use associated with attenuated inflammatory responses, and heavy ethanol consumption linked with augmentation of inflammation. Ethanol may modify innate immunity via functional alterations of the cells of the innate immune system. Mounting evidence indicates that ethanol can diversely affect antigen recognition and intracellular signaling events, which include activation of mitogen activated protein kinases, and NFkappaB, mediated by Toll-like receptors, leading to altered inflammatory responses. The mechanism(s) underlying these changes may involve dose-dependent effects of ethanol on the fluidity of cell membrane, resulting in interference with the timely assembly or disassembly of lipid rafts. Ethanol could also modify cell activation by specific interactions with cell membrane molecules.

[TNF-alpha and carbohydrate and lipid parameters in overweight and obese children]

INTRODUCTION

Tumor necrosis factor alpha (TNF-alpha) is suspected to play a role in obesity and concomitant metabolic disturbances. The aim of the study was to determine fasting serum concentrations of TNF-alpha in overweight and obese children and to analyse the relationships between TNF-alpha and insulin resistance and lipid disturbances. The additional aim was to assess correlations between TNF-alpha and total fat mass, body mass index (BMI), WHR, leptin and plasminogen activator inhibitor type 1 (PAI-1), as the factor of increased risk of atheromatosis.

MATERIAL AND METHODS

The study was performed in a group of 160 children aged 6-18.5 years: 127 overweight or obese and 33 healthy lean children (control group). The anthropometric measurements, BMI, WHR, fat-free mass, Tanner pubertal stage and blood pressure were determined. The fasting serum concentrations of TNF-alpha, glucose, insulin, lipids and fibrinogen were analysed in studied children. In overweight and obese subjects oral glucose tolerance test (OGTT) was done, serum leptin and plasma PAI-1 concentrations were determined. Atherogenic and insulin resistance indexes were counted. Statistic analysis was done.

RESULTS AND CONCLUSIONS

The serum TNF-alpha concentration in overweight and obese children and lean controls were comparable. This fact doesn't deny the role of TNF-alpha in pathogenesis of obesity. TNF-alpha concentration grows in serum of girls according to degree of abdominal obesity, determined with increase of WHR. Fat-free mass and BMI don't influence TNF-alpha level. Carbohydrate disturbances in obese children may not depend only on TNF-alpha. There are relationships between TNF-alpha and decreased HDL cholesterol and increased triglycerides (TG) levels in serum of overweight and obese children, mainly in II-III pubertal stage. Special care should be provided for children with excessive body weight at the beginning of puberty because of increased intensity of metabolic syndrome in this period and greater risk of early atheromatosis. Special care should be also provided for boys with increased TG serum levels, because of growing atherogenesis risk, determined with higher plasma concentration of PAI-1 in them and positive correlation between TNF-alpha and PAI-1. Regulation ofleptin production and secretion may also be under the control of other factors than TNF-alpha.

Aberrant acute-phase response in aged interleukin-6 knockout mice

This study was designed to determine whether the acute-phase response in aged mice is altered by interleukin (IL) 6 deficiency. Young and aged wild-type (WT) and IL-6 knockout (KO) BALB/C female mice were injected with lipopolysaccharide (LPS; 1.5 microg/g body weight). After 24 h, aged IL-6 KO mice had an improved survival when compared with aged WT mice. Serum levels of IL-6 in aged WT animals given LPS were determined and, as expected, were significantly higher when compared with young LPS-treated WT animals (P<0.05). Serum levels of the acute-phase protein, serum amyloid A, were 50% lower in aged LPS-treated IL-6 KO mice relative to aged WT mice given LPS (P<0.001). In contrast, the induction of LPS-binding protein was not affected by age or IL-6 deficiency in LPS-treated animals. Circulating levels of corticosterone were markedly reduced in aged LPS-treated IL-6 KO mice relative to aged WT mice given LPS. These data indicate that IL-6 is an important contributor to the outcome of the acute-phase response of aged individuals challenged with endotoxin. We conclude that the absence of IL-6, a cytokine that contributes to the elevated basal proinflammatory state observed in aging, can improve the ability of aged mice to withstand an otherwise lethal challenge of bacterial endotoxin.

[Correlation between serum homocysteine levels and selected atherosclerosis risk factors in children and adolescents with simple obesity]

Homocysteine is known as an independent risk factor of atherosclerosis. The aim of this study was assessment of serum homocysteine concentrations in obese children and evaluation of possible relationship between homocysteine and risk factors of atherosclerosis. 498 children with simple obesity were included into our study. There was a significant correlation between serum homocysteine levels and both traditional and new risk factors of atherosclerosis. The issues confirm a necessity of evaluation serum homocysteine levels of obese children in estimation of cardiovascular disease risk.

In vivo ethanol exposure down-regulates TLR2-, TLR4-, and TLR9-mediated macrophage inflammatory response by limiting p38 and ERK1/2 activation

Ethanol is known to increase susceptibility to infections, in part, by suppressing macrophage function. Through TLRs, macrophages recognize pathogens and initiate inflammatory responses. In this study, we investigated the effect of acute ethanol exposure on murine macrophage activation mediated via TLR2, TLR4, and TLR9. Specifically, the study focused on the proinflammatory cytokines IL-6 and TNF-alpha and activation of p38 and ERK1/2 MAPKs after a single in vivo exposure to physiologically relevant level of ethanol followed by ex vivo stimulation with specific TLR ligands. Acute ethanol treatment inhibited IL-6 and TNF-alpha synthesis and impaired p38 and ERK1/2 activation induced by TLR2, TLR4, and TLR9 ligands. We also addressed the question of whether ethanol treatment modified activities of serine/threonine-specific, tyrosine-specific phosphatases, and MAPK phosphatase type 1. Inhibitors of three families of protein phosphatases did not restore ethanol-impaired proinflammatory cytokine production nor p38 and ERK1/2 activation. However, inhibitors of serine/threonine protein phosphatase type 1 and type 2A significantly increased IL-6 and TNF-alpha levels, and prolonged activation of p38 and ERK1/2 when triggered by TLR4 and TLR9 ligands. In contrast, with TLR2 ligand stimulation, TNF-alpha production was reduced, whereas IL-6 levels, and p38 and ERK1/2 activation were not affected. In conclusion, acute ethanol exposure impaired macrophage responsiveness to multiple TLR agonists by inhibiting IL-6 and TNF-alpha production. Mechanism responsible for ethanol-induced suppression involved inhibition of p38 and ERK1/2 activation. Furthermore, different TLR ligands stimulated IL-6 and TNF-alpha production via signaling pathways, which showed unique characteristics.

Acute ethanol exposure inhibits macrophage IL-6 production: role of p38 and ERK1/2 MAPK

Acute ethanol consumption has been linked to an increase in infectious complications in trauma and burn patients. Ethanol modifies production of a variety of macrophage-derived immunoregulatory mediators. Lipopolysaccharide (LPS), a potent stimulator of inflammatory responses in macrophages, activates several intracellular signaling pathways, including mitogen-activated protein kinases (MAPK). In the current study, we investigated the effect of acute ethanol exposure on in vivo activation of p38 and extracellularly regulated kinases 1 and 2 (ERK1/2) MAPK in murine macrophages and the corresponding, LPS-stimulated interleukin (IL)-6 production. We demonstrated that a single dose of ethanol transiently down-regulated p38 and ERK1/2 activation levels (3-24 h after treatment) and impaired IL-6 synthesis. Ethanol-related reduction in IL-6 production was not further affected by the presence of inhibitors of p38 and ERK1/2 (SB 202190 and PD 98059, respectively). These results demonstrate that acute ethanol exposure can impair macrophage IL-6 production and indicate that this effect may result from ethanol-induced alterations in intracellular signaling through p38 and ERK1/2.

Age-dependent decrease in Toll-like receptor 4-mediated proinflammatory cytokine production and mitogen-activated protein kinase expression

Age-related changes in immunity render elderly individuals more susceptible to infections than the young. Previous work by our laboratory and others showed that macrophages from aged mice are functionally impaired. Macrophages produce proinflammatory cytokines, tumor necrosis factor alpha (TNF-alpha) and interleukin (IL)-6, when stimulated with lipopolysaccharide (LPS), which signals through Toll-like receptor-4 (TLR4) and requires activation of mitogen-activated protein kinases (MAPKs). We investigated whether aging is associated with alterations in TNF-alpha and IL-6 production and MAPK expression and activation in thioglycollate-elicited peritoneal macrophages from mice. Kinetics and LPS dose-responsiveness of macrophage TNF-alpha production did not differ by age. Unstimulated macrophages did not differ by age in their cytokine production. However, LPS-stimulated (100 ng/mL) cultures from aged mice produced 100 +/- 30 pg/mL TNF-alpha and 6000 +/- 2000 pg/mL IL-6, and those from young mice produced 280 +/- 50 pg/mL and 10,650 +/- 10 pg/mL, respectively (P<0.05). Likewise, levels of activated MAPKs did not differ by age in unstimulated macrophages, and LPS-stimulated macrophages from aged mice had <70% activated p38 and c-jun NH(2)-terminal kinase (JNK) than those of young controls. Of particular interest, we observed >25% reduction of total p38 and JNK in macrophages from aged mice relative to young. In addition, surface TLR4 levels did not vary with age. We conclude that macrophages from aged mice exhibited suppressed proinflammatory cytokine production, which correlated with diminished total levels and LPS-stimulated activation of p38 and JNK. These observations suggest that decreased MAPK expression could be a mechanism responsible for age-related deterioration of the immune system.

Antibodies to 70 kD and 90 kD heat shock proteins are associated with graft-versus-host disease in peripheral blood stem cell transplant recipients

The development of graft-versus-host disease (GVHD) can be modified by non-MHC factors. Based on our previous studies that showed an involvement of 70kD heat shock protein (hsp70) in the pathology of acute GVHD in a rat model, we determined serum levels of antibodies to hsp70, hsp90 and hsp60 in human recipients after allogeneic peripheral blood stem cell transplantation (PBSCT). Serum levels of these antibodies were correlated with GVHD status in the recipients. Twenty-nine recipients with high-risk haematological malignances, who received G-CSF mobilized allogeneic PBSCT from HLA matched family donors, were evaluated between 30 and 960 days after transplantation. Two recipients had no GVHD, 18 developed acute followed by chronic GVHD and nine developed only chronic GVHD. Patients with acute GVHD had a significant increase in IgM anti-hsp70 and/or anti-hsp90 early (30-90 days) after transplantation. In addition, an increase in IgM anti-hsp70 and/or anti-hsp90 antibodies preceded or accompanied chronic GVHD. Antibody levels returned to normal within the next 400 days in the majority of patients. Anti-hsp60 antibody levels were not different from control levels regardless of GVHD status. This study implies that the development of acute and/or chronic GVHD in humans is accompanied by an increase in anti-hsp70 and anti-hsp90 antibodies. Monitoring levels of anti-hsp70 and anti-hsp90 antibodies in stem cell transplant recipients may serve as a diagnostic tool and help to predict the onset of GVHD.

[Selected markers of bone metabolism in boys with constitutional delay of growth and puberty]

The aim of the study was to determine serum concentration and urinary excretion of selected parameters of bone metabolism in boys with constitutional delay of growth and puberty (CDGP) in the relation to pubertal stages. The study group consisted of 41 boys (aged 8 to 18 yrs) with CDGP. Patients were divided on the basis of Tanner's criteria into 4 groups according to the pubertal stage. Serum alkaline phosphatase (AP) activity and serum osteocalcin (OC) concentration as markers of bone growth, as well as urinary deoxypyridinoline (DPD) as a marker of bone resorption were determined. Serum AP activity in 31 (75.6%) boys was within normal age range. Mean values of serum AP activity increased insignificantly from I to IV stage of puberty. Serum OC concentrations were normal in 33 (80.5%) patients. Eight (19.5%) boys showed decreased values of serum OC concentration. Mean OC concentration insignificantly increased with the pubertal stages. DPD urinary excretion was within normal age range in all patients and was the highest in stage III of pubertal stage. No significant abnormalities of bone metabolism parameters in boys with constitutional delay of growth and puberty were found.

Reduced levels of Hsp70 result in a therapeutic effect of 15-deoxyspergualin on acute graft-versus-host disease in (DA x LEW)F1 rats

We have shown previously that increased levels of hsp70, and antibodies reactive with hsp70 parallel the onset and severity of graft-versus-host disease (GVHD) in a parent --> (DA x LEW)F1 rat model. In this study we have assessed the effect of reducing the levels of the 70 kDa heat shock protein (hsp70), on the morbidity and mortality of acute GVHD in (DA x LEW)F1 rats. The reduction was accomplished by the administration of 15-deoxyspergualin (DSG), an immunosuppressive agent which binds to a constitutively expressed member of the 70 kDa heat shock protein family. DSG administered via three different protocols reduced GVHD-associated morbidity. One of the regimens, which consisted of intermittent DSG administration, also significantly reduced GVHD associated mortality. This DSG treatment reduced hsp70 levels in spleen and lymph nodes, inhibited anti-hsp70 antibody production, and diminished the serum levels of IL-2, IFN-gamma, TNF-alpha, and IL-10. IL-4 levels in the serum did not change during GVHD and were not effected by DSG. These results show that the mechanism of DSG immunosuppressive effect in rat GVHD may involve DSG's capacity to bind to hsp70, which in turn may lead to a decrease in levels of circulating anti-hsp70 antibodies, and reduced production of cytokines.

hsp70, hsp32, and grp78 are increased in thermally injured skin with and without antithrombin(human) concentrate infusion

An acquired deficiency of antithrombin (AT), an anti-inflammatory protein, develops in patients with thermal injuries. Skin thermotolerance is regulated by heat shock protein (hsp) genes. hsp70, hsp32, hsp27, and glucose-regulated protein78 (grp78) were studied in burned and unburned human skin to determine whether correction of the AT deficiency modulated the intensity of expression of these proteins. Fifty-four human skin samples were prepared by Western blot analysis: 11 unburned and 22 burned control skin samples and 7 unburned and 14 burned skin samples from patients treated with AT(Human), or AT(H). The intensity of hsp32 expression in burned AT(H)-treated skin (P < .001) and in burned control skin (P < .01) was significantly increased compared with unburned control skin. The intensity of expression of hsp70 was statistically significant in burned AT(H)-treated skin compared with unburned control skin (P < .02), as was that of grp78 (P < .01). Thermally injured skin with or without AT(H) treatment had an increased expression of hsp70, hsp32, and grp78 compared with unburned control skin.

Effect of d-fenfluramine on the lymphocyte response of HIV+ humans

The objective of this study was to analyse the effect of d-dexfenfluramine (d-FEN) on the human lymphocyte response, in vitro. Experiments were designed to determine whether d-FEN augments specific human immune parameters associated with protection from opportunistic microbial pathogens and particularly focuses on d-FEN as a means by which to augment the function of CD8+ and CD4+ lymphocytes. Lymphocytes were examined for three reasons: (1) for their ability to inhibit the growth of Candida albicans; (2) for their ability to proliferate in response to a mitogen; and, (3) their cytokine profile (vis., production of IL-2, IFN-gamma and TNF-alpha). Peripheral blood mononuclear cells (PBMC) were obtained from 20 HIV+ patients. The patients were diagnosed as HIV+ within the past 0.5-9 years. d-FEN was found to augment the capacity of CD8+ lymphocytes to inhibit the growth of the opportunistic microbial pathogen, C. albicans. d-FEN enhanced the capacity of CD4+ lymphocytes to proliferate in response to the mitogen, Concanavalin A, and to increase the amount of IL-2 produced by CD4+ and CD8+ lymphocytes from AIDS patients. d-FEN increased the number of CD4+ and CD8+ lymphocytes that produced IFN-gamma from either non-AIDS or AIDS patients and increased the number of AIDS patient's CD8+ lymphocytes that produce TNF-alpha. These in vitro data suggest that d-FEN may be effective in enhancing immune function in immunocompromised individuals.

Expression of 70-kDa heat-shock protein during acute graft-versus-host disease

Acute lethal graft-versus-host disease (GVHD) was induced in unirradiated (LEW x DA)F1 rats by injection of DA parental lymphoid cells. Control rats received the same dose of (LEW x DA)F1 cells. The level of hsp70 at different stages of GVHD was examined in the spleen, lymph nodes, thymus, liver, lung, kidney, heart, and skeletal muscles of GVHD and control animals. Hsp70 was present in all organs analyzed in both groups and, with the exception of the spleen and lymph nodes, detectable levels remained constant during the disease. However, the spleen and lymph nodes of GVHD rats showed distinct changes in the hsp70 levels throughout the course of the disease. Expression of hsp70 in spleen and lymph nodes was augmented 7 and 14 days after induction of the disease. During the last stages of GVHD, 18-21 days after the induction, expression of hsp70 diminished to a level similar to that in untreated and control animals. Elevated levels of hsp70 in lymphoid organs during GVHD suggest an involvement of hsp70 in the pathology of the disease.

Antibodies specific for the 70-kDa heat-shock protein parallel the development of acute graft-versus-host disease in (DA x LEW)F1 rats

Acute GVHD was induced in unirradiated (DA x LEW)F1 rats by the injection of parental DA lymphoid cells. Serum sequentially derived from such animals was found to contain increased levels of antibodies reactive with 70-kDa heat-shock protein (hsp70). Elevated levels of antibody to hsp70 were detected as early as 7 days and were maximal 14 days after the induction of GVHD. These increased levels of antibodies reactive with hsp70 paralleled the onset of the signs and symptoms associated with the development of GVHD. Increased anti-hsp70 reactivity in GVHD sera was associated statistically with increased levels of hsp70-reactive IgM, IgG2a, and IgG2b. In addition, GVHD sera reacted with a 70-kDa protein found within (DA x LEW)F1 lymphoid tissue. These results demonstrate that increased levels of antibodies to hsp70 parallel the onset and development of GVHD in an acute model and are the first to show that antibodies reactive with hsp70 are associated with an ongoing disease process.

Neurochemical, endocrine and immunological responses to stress in young and old Fischer 344 male rats

Two experiments were performed. In the first, a 20 min conditioned emotional response (CER) paradigm was used to compare the neurochemical, endocrine and immunological responses to stress of 7- and 22-month-old Fischer 344 (F344) male rats. In the second, corticosterone levels 20 min following ether stress, and regional brain type I and II corticosterone receptor densities were examined using 7- and 17.5-month-old F344 male rats. Dopamine (DA) metabolism in old nonstressed rats was significantly reduced in the medial frontal cortex, neostriatum, nucleus accumbens and hypothalamus, but not in the amygdala. The CER procedure, nevertheless, increased medial frontal cortical, nucleus accumbens and amygdaloid DA turnover in both the young and old rats. The young and old nonstressed rats did not evidence differences in norepinephrine (NE) and serotonin (5-HT) concentrations. However, stress resulted in a decrease in medial frontal cortical 5-hydroxyindoleacetic acid (5-HIAA) and hypothalamic 5-HT levels in old but not in young animals. These observations suggest age-related differences in the response of central NE and 5-HT systems to stress. Ether and the CER procedure led to exaggerated corticosterone responses in the old rats (17.5 and 22 month, respectively). Hippocampal type I but not type II corticosterone receptors were decreased by 47% in the 17.5-month-old rats. Thus, age-related changes in hippocampal corticosterone receptor types do not occur in unison, and the exacerbated corticosterone response to stress precedes the reported down-regulation of hippocampal type II corticosterone receptors in aged rats. Age-related changes were not observed in the concentrations of corticosterone receptors in other brain regions, or in the prolactin response to stress. The old rats, however, evidenced a reduction in the availability of the renin substrate, angiotensinogen, and in stress-induced renin secretion. Immune function was impaired in the old nonstressed rats, and further compromised by exposure to the CER procedure. In comparison to the young control rats, the old nonstressed rats showed an increased percentage of splenic large granular lymphocytes, reduced splenic natural killer cytotoxicity, and impaired Con-A-stimulated splenic T lymphocyte proliferation. Reductions in T splenic cell proliferation and natural killer cytotoxicity were observed in the young rats subjected to the CER paradigm, but not to the same extent as in the old rats. These observations indicate that aging male F344 rats evidence major alterations in basal central monoamine, endocrine and immune functions, and an increased sensitivity of these systems to stress.

The effects of amino acids on protein degradation and translocation of non-histone proteins to the nucleus in lymphocytes

Tryptophan, phenylalanine and leucine have two parallel effects in cultured lymphocytes, they inhibit cellular proteolysis and increase the translocation of non-histone proteins to the nucleus. The latter is associated with an increased cellular binding of [3H]actinomycin D, indicating an altered structure of chromatin. The amino acids also inhibit the cellular uptake of [3H]chloroquine, suggesting that inhibited protein degradation is lysosomal. Several amine catabolites of tryptophan and phenylalanine, some of which are known to play a role as biogenic amines, have similar actions, and can explain, at least in part, the effects of their parent amino acids. Fractionation of the nuclear 3H-labeled non-histone proteins according to pH 2.5-6.5 shows that such proteins with a high rate of degradation in untreated cells correspond to the 3H-labeled non-histone proteins with a high rate of translocation in tryptophan treated cells. These data suggest that the degradation and the translocation of the non-histone proteins are linked and that the increased translocation of the non-histone proteins to the nucleus may be the consequence of inhibited lysosomal degradation of these proteins by the amino acids.