VCAM-1-targeted nanoparticles to diagnose, monitor and treat atherosclerosis.

Vascular cell adhesion molecule-1 (VCAM-1) was identified over 2 decades ago as an endothelial adhesion receptor involved in leukocyte recruitment and cell-based immune responses. In atherosclerosis, a chronic inflammatory disease of the blood vessels that is the leading cause of death in the USA, endothelial VCAM-1 is robustly expressed beginning in the early stages of the disease. The interactions of circulating immune cells with VCAM-1 on the activated endothelial cell surface promote the uptake of monocytes and the progression of atherosclerotic lesions in susceptible vessels. Herein, we review the role of VCAM-1 in atherosclerosis and the use of VCAM-1 binding peptides, antibodies and aptamers as targeting agents for nanoplatforms for early detection and treatment of atherosclerotic disease.

Preferential uptake of antibody targeted calcium phosphosilicate nanoparticles by metastatic triple negative breast cancer cells in co-cultures of human metastatic breast cancer cells plus bone osteoblasts.

Calcium phosphosilicate nanoparticles (CPSNPs) are bioresorbable nanoparticles that can be bioconjugated with targeting molecules and encapsulate active agents and deliver them to tumor cells without causing damage to adjacent healthy tissue. Data obtained in this study demonstrated that an anti-CD71 antibody on CPSNPs targets these nanoparticles and enhances their internalization by triple negative breast cancer cells in-vitro. Caspase 3,7 activation, DNA damage, and fluorescent microscopy confirmed the apoptotic breast cancer response caused by targeted anti-CD71-CPSNPs encapsulated with gemcitabine monophosphate, the active metabolite of the chemotherapeutic gemcitabine used to treat cancers including breast and ovarian. Targeted anti-CD71-CPSNPs encapsulated with the fluorophore, Rhodamine WT, were preferentially internalized by breast cancer cells in co-cultures with osteoblasts. While osteoblasts partially internalized anti-CD71-GemMP-CPSNPs, their cell growth was not affected. These results suggest that CPSNPs may be used as imaging tools and selective drug delivery systems for breast cancer that has metastasized to bone.

Physical Activity Plus Energy Restriction Prevents 4T1.2 Mammary Tumor Progression, MDSC Accumulation, and an Immunosuppressive Tumor Microenvironment.

Physical activity and the prevention of weight gain decrease breast cancer incidence and improve survival. Unraveling the biological mechanisms underlying these cancer prevention effects is difficult because activity and dietary restriction are often linked. The goal of this study was to determine whether physical activity (PA), preventing weight gain via energy restriction (ER), or the combination was most effective in delaying tumor growth, reducing metastatic progression, and improving survival in the 4T1.2 mammary tumor model. Furthermore, we determined whether any of these interventions prevented the expansion of protumor immunosuppressive cells and altered the tumor microenvironment (TME). Female BALB/c mice (n = 7-20/group) were randomized to sedentary (SED) or PA wheel cages and fed ad libitum (AL) or 90% of control food intake (ER). After 8 weeks on the interventions, mice were inoculated with 5 × 104 4T1.2luc cells into the 4th mammary fat pad and continued on their respective intervention. PA+ER significantly delayed primary tumor growth (final tumor volume, 0.193 ± 0.042 vs. 0.369 ± 0.049 cm3, P < 0.001), reduced metastatic burden in the lungs (0.72 ± 0.36 vs. 16.27 ± 6.98, P = 0.054) and increased survival (median survival, 68 vs 40 days, P = 0.043) compared with SED+AL mice. PA+ER also reduced the expression level of metastatic and immunosuppressive genes and resulted in favorable changes in immune cell infiltrates in the tumor. These data suggest that both PA and ER are needed to reduce tumor growth, delay metastatic progression, and improve survival, and that this protection is associated with changes in immune-mediated mechanisms.

A Spontaneous 3D Bone-On-a-Chip for Bone Metastasis Study of Breast Cancer Cells.

Bone metastasis occurs at ≈70% frequency in metastatic breast cancer. The mechanisms used by tumors to hijack the skeleton, promote bone metastases, and confer therapeutic resistance are poorly understood. This has led to the development of various bone models to investigate the interactions between cancer cells and host bone marrow cells and related physiological changes. However, it is challenging to perform bone studies due to the difficulty in periodic sampling. Herein, a bone-on-a-chip (BC) is reported for spontaneous growth of a 3D, mineralized, collagenous bone tissue. Mature osteoblastic tissue of up to 85 µm thickness containing heavily mineralized collagen fibers naturally formed in 720 h without the aid of differentiation agents. Moreover, co-culture of metastatic breast cancer cells is examined with osteoblastic tissues. The new bone-on-a-chip design not only increases experimental throughput by miniaturization, but also maximizes the chances of cancer cell interaction with bone matrix of a concentrated surface area and facilitates easy, frequent observation. As a result, unique hallmarks of breast cancer bone colonization, previously confirmed only in vivo, are observed. The spontaneous 3D BC keeps the promise as a physiologically relevant model for the in vitro study of breast cancer bone metastasis.

Bioactive growth hormone in older men and women: It's relationship to immune markers and healthspan.

OBJECTIVE: The consequences of age-related decline in the somatotropic axis of humans are complex and remain largely unresolved. We tested the hypothesis that hGH measurements of plasma by bioassay vs immunoassay from samples obtained from free-living, elderly individuals would reveal a dichotomy in GH activities that are correlated with the functional status of the donors, i.e. their healthspan. DESIGN: Forty-one men and women of advanced age (men: N=16, age, 80.5±6.5years; height, 173.1±6.9cm; body mass, 81.8±13.0kg) and (women: N=25, age, 80.7±7.2years; height, 157.7±6.0cm; body mass, 68.8±17kg), were recruited for a cross-sectional study. Participants filled out PROMIS (Patient-Reported Outcomes Measurement Information System, U. S. Department of Health and Human Services) scales, undertook physical performance tests and had fasted blood samples obtained at rest for measurement of hormonal and immunology biomarkers. RESULTS: When measured by the well-established rat tibial line GH bioassay, one half of the plasma samples (n=20) contained bioassayable GH (bGH), but the other half (n=21) failed to mount increases in tibial plate width above saline injected controls. This difference did not correlate with the age, sex or physical functionality of the plasma donor. It also did not correlate with hGH concentrations measured by immunoassay. In those cases in which bGH was detected, various hierarchical regression models predicted that GHRH, c-peptide, VEGF, NPY, IL-4 and T-regulatory lymphocytes were associated with the difference and predicted bGH. CONCLUSION: Results from this study suggest that the actions of bGH at the cellular level may be modified by other factors and that this may explain the lack of correlations observed in this study.

Role of Megakaryocytes in Breast Cancer Metastasis to Bone.

Little is known about how megakaryocytes may affect metastasis beyond serving as a source of platelets. In this study, we explored the functional implications of megakaryocyte accumulation in the femurs of mice after injection of metastatic or non-metastatic breast cancer cells in 4T1.2 BALB/cJ and MDA-MB-231 nude mouse models. At bone metastatic sites, but not primary growth sites, tumor growth was associated with increased megakaryopoiesis in both model systems. In the orthotopic BALB/cJ model, extramedullary hematopoiesis occurred in the spleen, resulting in a four-fold increase in megakaryocytes. In support of the hypothesis that reducing megakaryocytes may reduce metastasis, we found that thrombopoietin-deficient mice exhibited a 90% relative decrease in megakaryocytes, yet they developed more aggressive metastasis than wild-type hosts. In human clinical specimens, we observed an increase in megakaryocytes in the bone marrow of 6/8 patients with metastatic breast cancer compared with age- and gender-matched controls. Taken together, our results suggested that an increase in megakaryocytes occurring in response to metastatic cells entering the bone marrow confers some measure of protection against metastasis, challenging present views on the role of megakaryocytes in this setting. Cancer Res; 77(8); 1942-54. ©2017 AACR.

Three-Dimensional in Vitro Model to Study Osteobiology and Osteopathology.

The bone is an amazing organ that grows and remodels itself over a lifetime. It is generally accepted that bone sculpting in response to stress and force is carried out by groups of cells contained within bone multicellular units that are coordinated to degrade existing bone and form new bone. Because of the nature of bone and the extensiveness of the skeleton, it is difficult to study bone remodeling in vivo. On the other hand, because the bone contains a complex environment of many cell types, is it possible to study bone remodeling in vitro? We propose that one can at minimum study the interaction between osteoblasts (bone formation) and osteoclasts (bone degradation) in a three dimensional (3D) "bioreactor". Furthermore, one can add bone degrading metastatic cancer cells, and study how they contribute to and take part in the bone degradation process. We have primarily cultured and differentiated MC3T3-E1 osteoblasts for long periods (2-10 months) before addition of bone marrow osteoclasts and/or metastatic (MDA-MB-231), metastasis suppressed (MDA-MB-231BRMS1) or non-metastatic (MCF-7) breast cancer cells. In the co-culture of osteoblasts and osteoclasts there was clear evidence of matrix degradation. Loss of matrix was also evident after co-culture with metastatic breast cancer cells. Tri-culture permitted an evaluation of the interaction of the three cell types. The 3D system holds promise for further studies of cancer dormancy, hormone, and cytokine effects and matrix manipulation.

Dormancy and growth of metastatic breast cancer cells in a bone-like microenvironment.

Breast cancer can reoccur, often as bone metastasis, many years if not decades after the primary tumor has been treated. The factors that stimulate dormant metastases to grow are not known, but bone metastases are often associated with skeletal trauma. We used a dormancy model of MDA-MB-231BRMS1, a metastasis-suppressed human breast cancer cell line, co-cultured with MC3T3-E1 osteoblasts in a long term, three dimensional culture system to test the hypothesis that bone remodeling cytokines could stimulate dormant cells to grow. The cancer cells attached to the matrix produced by MC3T3-E1 osteoblasts but grew slowly or not at all until the addition of bone remodeling cytokines, TNFα and IL-ß. Stimulation of cell proliferation by these cytokines was suppressed with indomethacin, an inhibitor of cyclooxygenase and of prostaglandin production, or a prostaglandin E2 (PGE2) receptor antagonist. Addition of PGE2 directly to the cultures also stimulated cell proliferation. MCF-7, non-metastatic breast cancer cells, remained dormant when co-cultured with normal human osteoblast and fibroblast growth factor. Similar to the MDA-MB-231BRMS1 cells, MCF-7 proliferation increased in response to TNFα and IL-ß. These findings suggest that changes in the bone microenvironment due to inflammatory cytokines associated with bone repair or excess turnover may trigger the occurrence of latent bone metastasis.

In vitro mimics of bone remodeling and the vicious cycle of cancer in bone.

Bone remodeling is a natural process that enables growth and maintenance of the skeleton. It involves the deposition of mineralized matrix by osteoblasts and resorption by osteoclasts. Several cancers that metastasize to bone negatively perturb the remodeling process through a series of interactions with osteoclasts, and osteoblasts. These interactions have been described as the "vicious cycle" of cancer metastasis in bone. Due to the inaccessibility of the skeletal tissue, it is difficult to study this system in vivo. In contrast, standard tissue culture lacks sufficient complexity. We have developed a specialized three-dimensional culture system that permits growth of a non-vascularized, multiple-cell-layer of mineralized osteoblastic tissue from pre-osteoblasts. In this study, the essential properties of bone remodeling were created in vitro by co-culturing the mineralized collagenous osteoblastic tissue with actively resorbing osteoclasts followed by reinfusion with proliferating pre-osteoblasts. Cell-cell and cell-matrix interactions were determined by confocal microscopy as well as by assays for cell specific cytokines and growth factors. Osteoclasts, differentiated in the presence of osteoblasts, led to degradation of the collagen-rich extracellular matrix. Further addition of metastatic breast cancer cells to the co-culture mimicked the vicious cycle; there was a further reduction in osteoblastic tissue thickness, an increase in osteoclastogenesis, chemotaxis of cancer cells to osteoclasts and formation of cancer cells into large colonies. The resulting model system permits detailed study of fundamental osteobiological and osteopathological processes in a manner that will enhance development of therapeutic interventions to skeletal diseases.

Dietary selenium supplementation modifies breast tumor growth and metastasis.

The survival rate for breast cancer drops dramatically once the disease progresses to the metastatic stage. Selenium (Se) is an essential micronutrient credited with having high anticancer and chemopreventive properties. In our study, we investigated if dietary Se supplementation modified breast cancer development in vivo. Three diets supplemented with sodium selenite, methylseleninic acid (MSA) or selenomethionine (SeMet), as well as a Se-deficient and a Se-adequate diet were fed to mice before mammary gland inoculation of 4T1.2 cells. The primary tumor growth, the numbers of cancer cells present in lungs, hearts, livers, kidneys and femurs and several proinflammatory cytokines were measured. We found that inorganic selenite supplementation provided only short-term delay of tumor growth, whereas the two organic SeMet and MSA supplements provided more potent growth inhibition. These diets also affected cancer metastasis differently. Mice fed selenite developed the most extensive metastasis and had an increased incidence of kidney and bone metastasis. On the other hand, mice fed the SeMet diet showed the least amount of cancer growth at metastatic sites. The MSA diet also provided some protection against breast cancer metastasis although the effects were less significant than those of SeMet. The cytokine profiles indicated that serum levels of interlukin-2, interleukin-6, interferon γ and vascular endothelial growth factor were elevated in SeMet-supplemented mice. There was no significant difference in tumor growth and the patterns of metastasis between the Se-deficient and Se-adequate groups. Our data suggest that organic Se supplementation may reduce/delay breast cancer metastasis, while selenite may exacerbate it.

Is selenium a potential treatment for cancer metastasis?

Selenium (Se) is an essential micronutrient that functions as a redox gatekeeper through its incorporation into proteins to alleviate oxidative stress in cells. Although the epidemiological data are somewhat controversial, the results of many studies suggest that inorganic and organic forms of Se negatively affect cancer progression, and that several selenoproteins, such as GPXs, also play important roles in tumor development. Recently, a few scientists have examined the relationship between Se and metastasis, a late event in cancer progression, and have evaluated the potential of Se as an anti-angiogenesis or anti-metastasis agent. In this review, we present the current knowledge about Se compounds and selenoproteins, and their effects on the development of metastasis, with an emphasis on cell migration, invasion, and angiogenesis. In the cancers of breast, prostate, colorectal, fibrosarcoma, melanoma, liver, lung, oral squamous cell carcinoma, and brain glioma, there is either clinical evidence linking selenoproteins, such as thioredoxin reductase-1 to lymph node metastasis; in vitro studies indicating that Se compounds and selenoproteins inhibited cell motility, migration, and invasion, and reduced angiogenic factors in some of these cancer cells; or animal studies showing that Se supplementation resulted in reduced microvessel density and metastasis. Together, these data support the notion that Se may be an anti-metastastatic element in addition to being a cancer preventative agent.

Responses of proenkephalin Peptide F to aerobic exercise stress in the plasma and white blood cell biocompartments.

Proenkephalin Peptide F [107-140] is an enkephalin-containing peptide found predominantly within the adrenal medulla, co-packaged with epinephrine within the chromaffin granules. In vivo studies indicate that Peptide F has classic opioid analgesia effects; in vitro studies suggest potential immune cell interactions. In this investigation we examined patterns of Peptide F concentrations in different bio-compartments of the blood at rest and following sub-maximal cycle exercise to determine if Peptide F interacts with the white blood cell (WBC) bio-compartment during aerobic exercise. Eight physically active men (n=8) performed sub-maximal (80-85% V˙O2peak) cycle ergometer exercise for 30 min. Plasma Peptide F and WBC Peptide F immunoreactivity were examined pre-exercise, mid-exercise and immediately post-, 5-min post-, 15-min post-, 30-min post- and 60-min post-exercise and at similar time-points during a control condition (30 min rest). Peptide F concentrations significantly (p<0.05) increased at 5 and 60 min post-exercise, compared to pre-exercise concentrations. No significant increases in Peptide F concentrations in the WBC fraction were observed during or after exercise. However, a significant decrease was observed at 30 min post-exercise. An ultradian pattern of Peptide F distribution was apparent during rest. Furthermore, concentrations of T cells, B cells, NK cells, and total WBCs demonstrated significant changes in response to aerobic exercise. Data indicated that Peptide F was bound in significant molar concentrations in the WBC fraction and that this biocompartment may be one of the tissue targets for binding interactions. These data indicate that Peptide F is involved with immune cell modulation in the white blood circulatory biocompartment of blood.

Association between plasma cyclic guanosine monophosphate levels and hemodynamic instability during liver transplantation.

The activation of cyclic guanosine monophosphate (cGMP) production in patients with end-stage liver disease (ESLD) has been associated with hemodynamic instability during orthotopic liver transplantation (OLT). The aim of this prospective, observational study was to investigate the involvement of cGMP in the mediation of profound hypotension during liver graft reperfusion. An additional objective was to determine whether preoperative cGMP levels are associated with intraoperative hemodynamic instability. Forty-four consecutive patients undergoing OLT were included in the study. Blood samples for cGMP analysis were obtained from (1) the radial artery before the surgical incision; (2) the radial artery, portal vein, and flush blood during the anhepatic phase; and (3) the radial artery 20 minutes after liver graft reperfusion. On the basis of a statistical analysis, the patients were divided into 2 groups: group 1 (preoperative cGMP level ≥ 0.05 µmol/L) and group 2 (preoperative cGMP level < 0.05 µmol/L). We demonstrated a significant correlation between the preoperative levels of cGMP and the amount of catecholamine required to maintain hemodynamic stability during reperfusion (r = 0.52, P < 0.001), the length of the hospital stay (r = 0.38, P = 0.01), and the length of the intensive care unit (ICU) stay (r = 0.44, P = 0.004). We also demonstrated a significantly higher intraoperative catecholamine requirement (P < 0.001) and a prolonged postoperative ICU stay (P = 0.02) in group 1 patients versus group 2 patients. In conclusion, this study demonstrates increased baseline cGMP production in patients with ESLD, which is significantly associated with severe hypotension during OLT. We suggest that preoperative levels of cGMP correlate with hemodynamic instability during liver graft reperfusion.

Changes in Cytokines of the Bone Microenvironment during Breast Cancer Metastasis.

It is commonly accepted that cancer cells interact with host cells to create a microenvironment favoring malignant colonization. The complex bone microenvironment produces an ever changing array of cytokines and growth factors. In this study, we examined levels of MCP-1, IL-6, KC, MIP-2, VEGF, MIG, and eotaxin in femurs of athymic nude mice inoculated via intracardiac injection with MDA-MB-231(GFP) human metastatic breast cancer cells, MDA-MB-231BRMS1(GFP), a metastasis suppressed variant, or PBS. Animals were euthanized (day 3, 11, 19, 27 after injection) to examine femoral cytokine levels at various stages of cancer cell colonization. The epiphysis contained significantly more cytokines than the diaphysis except for MIG which was similar throughout the bone. Variation among femurs was evident within all groups. By day 27, MCP-1, MIG, VEGF and eotaxin levels were significantly greater in femurs of cancer cell-inoculated mice. These pro-osteoclastic and angiogenic cytokines may manipulate the bone microenvironment to enhance cancer cell colonization.

Neuroendocrine-immune interactions and responses to exercise.

This article reviews the interaction between the neuroendocrine and immune systems in response to exercise stress, considering gender differences. The body's response to exercise stress is a system-wide effort coordinated by the integration between the immune and the neuroendocrine systems. Although considered distinct systems, increasing evidence supports the close communication between them. Like any stressor, the body's response to exercise triggers a systematic series of neuroendocrine and immune events directed at bringing the system back to a state of homeostasis. Physical exercise presents a unique physiological stress where the neuroendocrine and immune systems contribute to accommodating the increase in physiological demands. These systems of the body also adapt to chronic overload, or exercise training. Such adaptations alleviate the magnitude of subsequent stress or minimize the exercise challenge to within homeostatic limits. This adaptive capacity of collaborating systems resembles the acquired, or adaptive, branch of the immune system, characterized by the memory capacity of the cells involved. Specific to the adaptive immune response, once a specific antigen is encountered, memory cells, or lymphocytes, mount a response that reduces the magnitude of the immune response to subsequent encounters of the same stress. In each case, the endocrine response to physical exercise and the adaptive branch of the immune system share the ability to adapt to a stressful encounter. Moreover, each of these systemic responses to stress is influenced by gender. In both the neuroendocrine responses to exercise and the adaptive (B lymphocyte) immune response, gender differences have been attributed to the 'protective' effects of estrogens. Thus, this review will create a paradigm to explain the neuroendocrine communication with leukocytes during exercise by reviewing (i) endocrine and immune interactions; (ii) endocrine and immune systems response to physiological stress; and (iii) gender differences (and the role of estrogen) in both endocrine response to physiological stress and adaptive immune response.

Dynamic interaction between breast cancer cells and osteoblastic tissue: comparison of two- and three-dimensional cultures.

Breast cancer cell colonization of osteoblast monolayers grown in standard tissue culture (2D) is compared to colonization of a multi-cell-layer osteoblastic tissue (3D) grown in a specialized bioreactor. Colonization of 3D tissue recapitulates events observed in clinical samples including cancer penetration of tissue, growth of microcolonies, and formation of "Single cell file" commonly observed in end-stage pathological bone tissue. By contrast, adherent cancer cell colonies did not penetrate 2D tissue and did not form cell files. Thus, it appears that 3D tissue is a more biologically (clinically) relevant model than 2D monolayers in which to study cancer cell interactions with osteoblastic tissue. This direct comparison of 2D and 3D formats is implemented using MC3T3-E1 murine osteoblasts and MDA-MB-231 human metastatic breast cancer cells, or the metastasis-suppressed line, MDA-MB-231BRMS1, for comparison. When osteoblasts were co-cultured with metastatic cells, production of osteocalcin (a mineralization marker) decreased and secretion of the pro-inflammatory cytokine IL-6 increased in both 2D and 3D formats. Cancer cell penetration of the 3D tissue coincided with a changed osteoblast morphology from cuboidal to spindle-shaped, and with osteoblasts alignment parallel to the cancer cells. Metastasis-suppressed cells did not penetrate 3D tissue, did not cause a change in osteoblast morphology or align in rows. Moreover, they proliferated much less in the 3D culture than in the 2D culture in a manner similar to their growth in bone. In both systems, the cancer cells proliferated to a greater extent with immature osteoblasts compared to more mature osteoblasts.

Pre-osteoblastic MC3T3-E1 cells promote breast cancer growth in bone in a murine xenograft model.

The bones are the most common sites of breast cancer metastasis. Upon arrival within the bone microenvironment, breast cancer cells coordinate the activities of stromal cells, resulting in an increase in osteoclast activity and bone matrix degradation. In late stages of bone metastasis, breast cancer cells induce apoptosis in osteoblasts, which further exacerbates bone loss. However, in early stages, breast cancer cells induce osteoblasts to secrete inflammatory cytokines purported to drive tumor progression. To more thoroughly evaluate the role of osteoblasts in early stages of breast cancer metastasis to the bones, we used green fluorescent protein-labeled human breast cancer cell lines MDA-MB-231 and MDA-MB-435, which both induce osteolysis after intra-femoral injection in athymic mice, and the murine pre-osteoblastic cell line MC3T3-E1 to modulate osteoblast populations at the sites of breast cancer metastasis. Breast cancer cells were injected directly into the femur with or without equal numbers of MC3T3-E1 cells. Tumors grew significantly larger when co-injected with breast cancer cells and MC3T3-E1 cells than injected with breast cancer cells alone. Osteolysis was induced in both groups, indicating that MC3T3-E1 cells did not block the ability of breast cancer cells to cause bone destruction. MC3T3-E1 cells promoted tumor growth out of the bone into the extraosseous stroma. These data suggest that breast cancer cells and osteoblasts communicate during early stages of bone metastasis and promote tumor growth.

Release of cytokines and hemodynamic instability during the reperfusion of a liver graft.

The objectives of this prospective, observational study were (1) to determine whether a transplanted liver graft releases proinflammatory cytokines into the systemic circulation upon reperfusion and (2) to determine whether they contribute to any subsequent hemodynamic instability observed after graft reperfusion (if this release occurs). Blood samples from 17 consecutive patients undergoing liver transplantation were analyzed for cytokines, including tumor necrosis factor α (TNF-α), interleukin-1ß (IL-1ß), IL-2, IL-6, and IL-8. Blood samples were obtained from the radial artery, portal vein, and flush blood (a sample taken from a catheter placed above the infrahepatic inferior vena cava clamp). The amount of catecholamines necessary to maintain a mean arterial pressure between 65 and 75 mm Hg during graft reperfusion was compared with the level of cytokines. A statistical analysis was performed with the least squares method, Kendall's tau-b test, and regression analysis. We demonstrated that flush blood from the liver grafts contained a significant amount and variety of cytokines. Most of these were removed by graft irrigation. The concentration of TNF-α in samples obtained from flush blood at the end of liver irrigation was significantly higher than the concentration in samples obtained from the radial artery (P = 0.0067) or portal vein (P = 0.0003) before reperfusion. This correlated directly with the amount of catecholamines used to treat hemodynamic instability. Although there were increased levels of IL-1ß, IL-2, and IL-8 in the flush blood, there was no statistically significant correlation between the levels of these cytokines and the amount of catecholamines used.

Leukocyte ß2-adrenergic receptor expression in response to resistance exercise.

PURPOSE: Epinephrine and norepinephrine mediate interactions between the neuroendocrine and the immune systems to alter immune cell activity. Although both systems respond to exercise stress, less is known about how they interact in response to such stress. The purpose of this investigation was to examine ß2-adrenergic receptor (ß2-ADR) expression on circulating leukocytes to an acute bout of resistance exercise in men and women. METHODS: Resistance-trained men (n = 8; mean ± SD age = 24.63 ± 5.07 yr, body mass index = 26.09 ± 2.21 kg·m(-2)) and women (n = 7; age = 22.13 ± 3.09 yr, body mass index = 22.63 ± 2.03 kg·m(-2)) performed an acute resistance exercise protocol (six sets of five-repetition maximum heavy squats) and a control test (i.e., identical conditions with no exercise) in a balanced, randomized order. Using a within-subject design, ß2-ADR expressions on circulating leukocytes were evaluated with flow cytometry, and plasma epinephrine and norepinephrine were evaluated with high-performance liquid chromatography. RESULTS: Plasma epinephrine and norepinephrine increased during the exercise bout and returned to baseline during recovery. ß2-ADR expression on monocytes was elevated in anticipation of the exercise protocol. ß2-ADR expression on monocytes and granulocytes decreased during the exercise. ß2-ADR expression on lymphocytes was elevated during the recovery time points. CONCLUSIONS: In conclusion, ß2-ADR expression on leukocyte subpopulations changes in response to acute heavy resistance exercise protocol. The present findings provide insights into the potential temporal interactions between the neuroendocrine and the immune systems in response to the physiological stress of acute heavy resistance exercise in men and women.

Glucocorticoid receptor expression on human B cells in response to acute heavy resistance exercise.

OBJECTIVE: To examine glucocorticoid receptor (GCR) expression on B lymphocytes in response to an acute bout of resistance exercise. METHODS: Using a within-subject design, resistance-trained women (n = 7; age: 22.13 ± 3.09 years; height: 1.69 ± 0.084 m; body weight: 65.60 ± 10.01 kg; body mass index: 22.63 ± 2.03 kg/m²; means ± SD) and men (n = 8; age: 23.28 ± 4.26 years; height: 1.73 ± 0.086 m; body weight: 73.93 ± 12.71 kg; body mass index: 24.51 ± 2.61 kg/m²; means ± SD) performed an acute resistance exercise protocol (6 sets of 5 repetition maximum heavy squats) and a control test in a balanced, randomized order. Blood samples were obtained before, during, and immediately after exercise, and after 1, 6, and 24 h of recovery. GCR expression on circulating B lymphocytes was evaluated with flow cytometry, and circulating cortisol was assayed. RESULTS: Resting GCR expression on B lymphocytes was similar between men and women. GCR expression was elevated in anticipation of exercise (p = 0.047), decreased during exercise (p = 0.049), and increased during recovery (p = 0.05 and p = 0.03 after 1 and 6 h of recovery, respectively). Trends for gender differences were apparent before and during exercise, and after 6 h of recovery. Men had significantly higher cortisol responses during (p = 0.002) and after exercise (p = 0.094) compared to before exercise. In women, however, circulating cortisol concentrations did not significantly increase in response to the squat exercise protocol. CONCLUSIONS: GCR expression on B lymphocytes decreased during resistance exercise and increased during recovery. Circulating cortisol increased during exercise in men only. Responses were attenuated in women compared to men. Our data provide insights into the temporal interactions between the endocrine and immune systems in response to acute heavy resistance exercise in men and women.