M. D. Hinchado

Inflammatory/stress feedback dysregulation in women with fibromyalgia.

Objective: Although one of the current hypotheses of the aetiology of fibromyalgia (FM) syndrome involves inflammatory and neuroendocrine disorders, its biophysiology still remains unclear. The purpose of the present investigation was to study the systemic inflammatory and stress responses, as well as the innate response mediated by monocytes and neutrophils in FM patients. Methods: Twenty-five women diagnosed with primary FM and 20 age-matched healthy women (control group) were enrolled in the study. Circulating ‘neuroendocrine-stress’ biomarkers (CRH, ACTH, cortisol, NA, eHsp72, serotonin and IGF-1) were evaluated by ELISA. Serum IL-8 and CRP concentrations were also determined by ELISA, and inflammatory cytokine release by monocytes [IL-1β, TNFα, IL-6, IL-10, IL-18, monocyte chemotactic protein-1 (MCP-1) and RANTES] was evaluated by the Luminex BioPlex system. The phagocytic process of neutrophils (chemotaxis, phagocytosis and microbicide capacity) was also evaluated. Results: FM patients showed an inflammatory state accompanied by an altered stress response. This is mainly manifested by high circulating levels of IL-8 and CRP (in 100% of the FM group), high circulating levels of cortisol, and increased systemic levels of NA and eHsp72. There is also increased release of inflammatory cytokines (IL-1β, TNFα, IL-6, IL-10, IL-18 and MCP-1) by monocytes, and enhanced activation of the functional capacity of neutrophils (chemotactic, phagocytic and fungicidal activities). Conclusion: An inflammatory/stress feedback dysregulation underlies FM. Whether dysregulation of the stress response is the cause of the inflammatory dysregulation or vice versa is also discussed.

The effect of stress-inducible extracellular Hsp72 on human neutrophil chemotaxis: a role during acute intense exercise.

We studied the physiological role of the 72 kDa extracellular heat shock protein (Hsp72, a stress-inducible protein) in modulating neutrophil chemotaxis during a single bout of intense exercise performed by sedentary women, together with various cell mechanisms potentially involved in the modulation. For each volunteer, we evaluated neutrophil chemotaxis and serum Hsp72 concentration before and immediately after a single bout of exercise (1 h on a cycle ergometer at 70% VO2 max), and 24 h later. Both parameters were found to be stimulated by the exercise, and had returned to basal values 24 h later. In vitro, there was a dose-dependent increase in chemotaxis when neutrophils were incubated both with physiological Hsp72 concentrations and with a 100 × greater concentration. The chemotaxis was greater when the neutrophils were incubated with the post-exercise Hsp72 concentration than with the basal concentration, suggesting a physiological role for this protein in the context of the stimulation of neutrophil chemotaxis by intense exercise. The 100 × Hsp72 concentration stimulated chemotaxis even more strongly. In addition, Hsp72 was found to have chemoattractant and chemokinetic effects on the neutrophils at physiological concentrations, with these effects being significantly greater with the post-exercise than with the basal Hsp72 concentration. The Hsp72-induced stimulation of neutrophil chemotaxis disappeared when the toll-like receptor 2 (TLR-2) was blocked, and phosphatidylinositol-3-kinase (PI3K), extracellular signal-regulated kinase (ERK), and nuclear transcription factor kappa B (NF-κB) were also found to be involved in the signaling process. No changes were observed, however, in neutrophil intracellular calcium levels in response to Hsp72. In conclusion, physiological concentrations of the stress protein Hsp72 stimulate human neutrophil chemotaxis through TLR-2 with its cofactor CD14, involving ERK, NF-κB, and PI3K, but not iCa2 + , as intracellular messengers. In addition, Hsp72 seems to participate in the stimulation of chemotaxis induced by a single bout of intense exercise performed by sedentary women.

Neuroimmunomodulation during Exercise: Role of Catecholamines as ‘Stress Mediator’ and/or ‘Danger Signal’ for the Innate Immune Response

Exercise-induced neuroimmunomodulation is clearly accepted today. The present article reviews the main literature concerning the immunomodulatory capacity of catecholamines on the innate immune response during physical exercise, and presents our laboratory’s latest results on this topic. It is well known that the effects of exercise on the immune system are mediated by the ‘stress hormones and mediators’. Although catecholamines have usually been regarded as immunosuppressors, they may stimulate innate immune response mechanisms (such as phagocytic function) during exercise-induced stress, even without previous antigenic stimulation. The exercise-induced stimulation of the phagocytic response in particular and the innate responses in general have been considered as a prevention strategy of the athlete’s organism in order to prevent the entry and/or maintenance of antigens in a situation where the adaptive immune response seems to be depressed, and thus it has been suggested that catecholamines participate as a ‘stress mediator’ of these effects. Given this hypothesis, it is also suggested here that catecholamines may be the first ‘danger signal’ to the immune system during exercise-induced stress.

Fibromyalgia: anti-inflammatory and stress responses after acute moderate exercise.

Fibromyalgia (FM) is characterized in part by an elevated inflammatory status, and “modified exercise” is currently proposed as being a good therapeutic help for these patients. However, the mechanisms involved in the exercise-induced benefits are still poorly understood. The objective was to evaluate the effect of a single bout of moderate cycling (45 min at 55% VO2 max) on the inflammatory (serum IL-8; chemotaxis and O2 − production by neutrophils; and IL-1β, TNF-α, IL-6, IL-10, and IL-18 release by monocytes) and stress (cortisol; NA; and eHsp72) responses in women diagnosed with FM compared with an aged-matched control group of healthy women (HW). IL-8, NA, and eHsp72 were determined by ELISA. Cytokines released by monocytes were determined by Bio-Plex® system (LUMINEX). Cortisol was determined by electrochemoluminiscence, chemotaxis was evaluated in Boyden chambers and O2 − production by NBT reduction. In the FM patients, the exercise induced a decrease in the systemic concentration of IL-8, cortisol, NA, and eHsp72; as well as in the neutrophil’s chemotaxis and O2 − production and in the inflammatory cytokine release by monocytes. This was contrary to the completely expected exercise-induced increase in all those biomarkers in HW. In conclusion, single sessions of moderate cycling can improve the inflammatory status in FM patients, reaching values close to the situation of aged-matched HW at their basal status. The neuroendocrine mechanism seems to be an exercise-induced decrease in the stress response of these patients.

Altered profile of chemokines in fibromyalgia patients

Background Fibromyalgia (FM) is a syndrome characterized by widespread chronic pain. Its aetiology is still poorly understood, and there are no haematochemical or instrumental tests on which to base a diagnosis. Recent studies suggest that its pathogenesis may involve cytokines, in particular, chemokines – cytokines that regulate cell traffic under both physiological and pathological conditions. The aim of this study was to determine possible differences in the profile of systemic concentrations of chemokines between FM patients and healthy women (HW; controls). Methods The study participants were women diagnosed with FM (n = 17) and a control group of HW (n = 10). Serum concentrations of thymus and activation-regulated chemokine (TARC)/(CCL17), monokine induced by gamma-interferon (MIG)/(CXCL9), macrophage-derived chemokine (MDC)/(CCL22), interferon-inducible T-cell alpha chemoattractant (I-TAC)/(CXCL11), eotaxin (CCL11), pulmonary and activation-regulated chemokine (PARC)/(CCL18) and hemofiltrate CC-chemokine-4 (HCC-4)/(CCL16) were determined by enzyme-linked immunosorbent assay and compared between the FM and HW groups. Results FM patients had elevated serum levels of the following inflammatory chemokines: TARC (P < 0.001), MIG (P < 0.001), MDC (P < 0.01), I-TAC (P < 0.01) and eotaxin (P < 0.05). No differences were found in the circulating concentrations of PARC and HCC-4 (homoeostatic chemokines). Conclusions Since FM patients present higher serum concentrations of inflammatory chemokines than HW, the evaluation of these biomarkers could help in the diagnosis of this syndrome.

Effects of Habitual Exercise on the eHsp72-Induced Release of Inflammatory Cytokines by Macrophages from Obese Zucker Rats

Regular exercise is a good non-pharmacological treatment of metabolic syndrome in that it improves obesity, diabetes, and inflammation. The 72 kDa extracellular heat shock protein (eHsp72) is released during exercise, thus stimulating the inflammatory responses. The aim of the present work was to evaluate the effect of regular exercise on the eHsp72-induced release of IL-1β, IL-6, and TNFα by macrophages from genetically obese Zucker rats (fa/fa) (ObZ), using lean Zucker (LZ) rats (Fa/fa) to provide reference values. ObZ presented a higher plasma concentration of eHsp72 than LZ, and exercise increased that concentration. In response to eHsp72, the macrophages from ObZ released less IL-1β and TNFα, but more IL-6, than macrophages from LZ. While eHsp72 stimulated the release of IL-1β, TNFα, and IL-6 in the macrophages from healthy LZ (with respect to the constitutive release), it inhibited the release of IL-1β and IL-6 in macrophages from ObZ. The habitual exercise improved the release of inflammatory cytokines by macrophages from ObZ in response to eHsp72 (it increased IL-1β and TNFα, and decreased IL-6), tending to values closer to those determined in healthy LZ. A deregulated macrophage inflammatory and stress response induced by eHsp72 underlies MS, and this is improved by habitual exercise.

Immune-Neuroendocrine Dysregulation in Patients with Osteoarthritis: A Revision and a Pilot Study

BACKGROUND Although osteoarthritis (OA) has predominantly been considered a noninflammatory degenerative arthropathy, there is growing evidence that various inflammatory and immunological processes might contribute to the onset, progression, and burden of the disease. OBJECTIVE The purpose of the present investigation was to study the systemic inflammatory and stress responses and the innate response mediated by neutrophils in OA patients. METHOD A group of patients diagnosed with primary OA according to the American College of Rheumatology criteria and a control group of age-matched healthy volunteers were enrolled in the study. Serum inflammatory cytokine levels (IL-1β, TNF-α, IL-8, IL-6, IL-10, and TGF-β) were evaluated using the Bio-Plex Luminex system. Circulating neuroendocrine-stress biomarkers, such as cortisol and extracellular 72 kDa heat shock protein (eHsp72), were measured by ELISA. The phagocytic and microbicide capacities of circulating neutrophils were evaluated by flow cytometry. All parameters were determined in all volunteers. RESULTS The OA patients showed an inflammatory state accompanied by an altered stress response. This was manifested in high circulating levels of the inflammatory cytokines IL-1β, TNF-α, IL-8, IL-6, and TGF-β and the stress protein eHsp72. There were also decreased systemic levels of cortisol, and a reduction in neutrophil phagocytic and microbicidal capacities. CONCLUSION An immune-neuroendocrine dysregulation affecting both systemic inflammatory and stress mediators and the function of innate immune cells underlies OA. This reflects an altered feedback between the innate/inflammatory and stress responses in this pathology.

Adrenoreceptors are involved in the stimulation of neutrophils by exercise-induced circulating concentrations of Hsp72: cAMP as a potential “intracellular danger signal”

Recently, the terms “stress mediators” or “danger signals” have come to be used to describe endogenous molecules that can be released in stress situations and activate the innate immune system even in the absence of antigenic stimuli. There is evidence suggesting that extracellular heat shock proteins of 72 kDa (eHsp72), together with noradrenaline (NA), are candidates as danger signals during exercise‐induced stress, interacting in the activation of neutrophils. Previous studies have shown that the post‐exercise circulating concentration of eHsp72 activates the phagocytic process of neutrophils with the participation of toll‐like receptor 2, but that other receptors must also be involved. The present investigation evaluates the role of adrenoreceptors in the activation of the chemotaxis, phagocytosis, and fungicidal capacity of neutrophils by the post‐exercise circulating concentration of eHsp72. The results showed that intact α‐ and β‐adrenoreceptors are necessary for the stimulation of all stages of the phagocytic process by eHsp72. Also, eHsp72 increased the intracellular levels of cAMP, suggesting that it is an “intracellular danger signal” during stress‐induced activation of neutrophils mediated by extracellular heat shock proteins. These results can contribute to better understanding the mechanisms involved in the regulation of the innate immune response mediated by “danger signals” during exercise, and probably during other stress situations. J. Cell. Physiol. 227: 604–608, 2012.

Combined activity of post-exercise concentrations of NA and eHsp72 on human neutrophil function: role of cAMP.

Extracellular heat shock proteins of 72 kDa (eHsp72) and noradrenaline (NA) can act as “danger signals” during exercise‐induced stress by activating neutrophil function (chemotaxis, phagocytosis, and fungicidal capacity). In addition, post‐exercise concentrations of NA increase the expression and release of Hsp72 by human neutrophils, and adrenoreceptors and cAMP are involved in the stimulation of neutrophils by eHsp72. This suggests an interaction between the two molecules in the modulation of neutrophils during exercise‐induced stress. Given this context, the aim of the present investigation was to study the combined activity of post‐exercise circulating concentrations of NA and eHsp72 on the neutrophil phagocytic process, and to evaluate the role of cAMP as intracellular signal in these effects. Results showed an accumulative stimulation of chemotaxis induced by NA and eHsp72. However, while NA and eHsp72, separately, stimulate the phagocytosis and fungicidal activity of neutrophils, when they act together they do not modify these capacities of neutrophils. Similarly, post‐exercise concentrations of NA and eHsp72 separately increased the intracellular level of cAMP, but NA and eHsp72 acting together did not modify the intracellular concentration of cAMP. These results confirm that cAMP can be involved in the autocrine/paracrine physiological regulation of phagocytosis and fungicidal capacity of human neutrophils mediated by NA and eHsp72 in the context of exercise‐induced stress. J. Cell. Physiol. 228: 1902–1906, 2013.