The sympathetic nervous response in inflammation

Autoimmune Rheumatic Diseases Masquerading as Psychiatric Disorders: A Case Series

Background

Neurological involvement has been found in many autoimmune diseases, with psychiatric abnormalities such as anxiety, depression, psychosis, and cognitive dysfunction.

Patients and Methods

Here, we describe a series of 5 consecutive cases of autoimmune diseases presenting with psychiatric symptoms as the predominant manifestation.

Result

Our case series suggests that psychiatric symptoms, mainly depression, can be one of the presenting symptoms of several autoimmune diseases that often cause a significant delay in diagnosis.

Conclusion

Any patient, particularly females, with a newly detected psychiatric disorder that responds poorly to medical management should be properly examined for underlying primary systemic autoimmune diseases.

Norepinephrine modulates IL-1β-induced catabolic response of human chondrocytes

Background

The influence of the sympathetic nervous system (SNS) on metabolism of bone and cartilage expressing β-adrenergic receptors (AR) was suggested. Here, we investigated whether the SNS functions as a modulator of cartilage metabolism induced by interleukin-1beta (IL-1β).

Methods

Human articular chondrocytes and articular cartilage were collected from patients with osteoarthritis (OA). Chondrocyte monolayer and cartilage explant culture were stimulated with IL-1β. The activity of β-ARs was modulated by an agonist, norepinephrine (NE), and antagonists, including propranolol, atenolol, nebivolol, and nadolol.

Results

The levels of β₁-, β₂-, and β₃-AR in OA cartilage and IL-1β-treated chondrocytes were lower than normal cartilage and untreated cells. Treatment of chondrocytes with IL-1β and β-blockers, including propranolol, atenolol, nebivolol, and nadolol, for 6 h significantly upregulated IL-1β-induced expression of MMP-1, -3, and − 13, compared to chondrocytes treated with IL-1β alone, indicating that antagonism of β-AR confers catabolic signals. On the other hand, NE antagonized IL-1β-induced catabolic response. In addition, NE significantly inhibited IL-1β-induced release of glycosaminoglycan (GAG) from cartilage explant culture. In addition, β-AR activity significantly affected IL-1β-stimulated phosphorylation of JNK and ERK. These results indicate that β-AR signal is associated with cartilage metabolism.

Conclusions

Our findings showed that β-ARs is a regulator of cartilage catabolism induced with IL-1β.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04598-7.

The anatomy of pain and suffering in the brain and its clinical implications

Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage. Chronic pain, with a prevalence of 20-30 % is the major cause of human suffering worldwide, because effective, specific and safe therapies have yet to be developed. It is unevenly distributed among sexes, with women experiencing more pain and suffering. Chronic pain can be anatomically and phenomenologically dissected into three separable but interacting pathways, a lateral 'painfulness' pathway, a medial 'suffering' pathway and a descending pain inhibitory pathway. One may have pain(fullness) without suffering and suffering without pain(fullness). Pain sensation leads to suffering via a cognitive, emotional and autonomic processing, and is expressed as anger, fear, frustration, anxiety and depression. The medial pathway overlaps with the salience and stress networks, explaining that behavioural relevance or meaning determines the suffering associated with painfulness. Genetic and epigenetic influences trigger chronic neuroinflammatory changes which are involved in transitioning from acute to chronic pain. Based on the concept of the Bayesian brain, pain (and suffering) can be regarded as the consequence of an imbalance between the two ascending and the descending pain inhibitory pathways under control of the reward system. The therapeutic clinical implications of this simple pain model are obvious. After categorizing the working mechanisms of each of the available treatments (pain killers, psychopharmacology, psychotherapy, neuromodulation, psychosurgery, spinal cord stimulation) to 1 or more of the 3 pathways, a rational combination can be proposed of activating the descending pain inhibitory pathway in combination with inhibition of the medial and lateral pathway, so as to rebalance the pain (and suffering) pathways.

COVID-19 is getting on our nerves: sympathetic neural activity and haemodynamics in young adults recovering from SARS-CoV-2

Key points

The impact of SARS‐CoV‐2 infection on autonomic and cardiovascular function in otherwise healthy individuals is unknown.

For the first time it is shown that young adults recovering from SARS‐CoV‐2 have elevated resting sympathetic activity, but similar heart rate and blood pressure, compared with control subjects.

Survivors of SARS‐CoV‐2 also exhibit similar sympathetic nerve activity and haemodynamics, but decreased pain perception, during a cold pressor test compared with healthy controls.

Further, these individuals display higher sympathetic nerve activity throughout an orthostatic challenge, as well as an exaggerated heart rate response to orthostasis.

If similar autonomic dysregulation, like that found here in young individuals, is present in older adults following SARS‐CoV‐2 infection, there may be substantial adverse implications for cardiovascular health.

Abstract

The novel severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) can elicit systemic adverse physiological effects. However, the impact of SARS‐CoV‐2 on autonomic and cardiovascular function in otherwise healthy individuals remains unclear. Young adults who tested positive for SARS‐CoV‐2 (COV+; n = 16, 8 F) visited the laboratory 35 ± 16 days following diagnosis. Muscle sympathetic nerve activity (MSNA), systolic (SBP) and diastolic (DBP) blood pressure, and heart rate (HR) were measured in participants at rest and during a 2 min cold pressor test (CPT) and 5 min each at 30° and 60° head‐up tilt (HUT). Data were compared with age‐matched healthy controls (CON; n = 14, 9 F). COV+ participants (18.2 ± 6.6 bursts min⁻¹) had higher resting MSNA burst frequency compared with CON (12.7 ± 3.4 bursts min⁻¹) (P = 0.020), as well as higher MSNA burst incidence and total activity. Resting HR, SBP and DBP were not different. During CPT, there were no differences in MSNA, HR, SBP or DBP between groups. COV+ participants reported less pain during the CPT compared with CON (5.7 ± 1.8 vs. 7.2 ± 1.9 a.u., P = 0.036). MSNA was higher in COV+ compared with CON during HUT. There was a group‐by‐position interaction in MSNA burst incidence, as well as HR, in response to HUT. These results indicate resting sympathetic activity, but not HR or BP, may be elevated following SARS‐CoV‐2 infection. Further, cardiovascular and perceptual responses to physiological stress may be altered, including both exaggerated (orthostasis) and suppressed (pain perception) responses, compared with healthy young adults.

The impact of SARS‐CoV‐2 infection on autonomic and cardiovascular function in otherwise healthy individuals is unknown.

For the first time it is shown that young adults recovering from SARS‐CoV‐2 have elevated resting sympathetic activity, but similar heart rate and blood pressure, compared with control subjects.

Survivors of SARS‐CoV‐2 also exhibit similar sympathetic nerve activity and haemodynamics, but decreased pain perception, during a cold pressor test compared with healthy controls.

Further, these individuals display higher sympathetic nerve activity throughout an orthostatic challenge, as well as an exaggerated heart rate response to orthostasis.

If similar autonomic dysregulation, like that found here in young individuals, is present in older adults following SARS‐CoV‐2 infection, there may be substantial adverse implications for cardiovascular health.

Alpha- and beta- adrenergic receptors regulate inflammatory responses to acute and chronic sleep fragmentation in mice

Sleep is a recuperative process, and its dysregulation has cognitive, metabolic, and immunological effects that are largely deleterious to human health. Epidemiological and empirical studies have suggested that sleep fragmentation (SF) as result of obstructive sleep apnea (OSA) and other sleep abnormalities leads to pronounced inflammatory responses, which are influenced by the sympathetic nervous system (SNS). However, the underlying molecular mechanisms contributing to SNS regulation of SF-induced inflammation are not fully understood. To assess the effects of the SNS upon inflammatory responses to SF, C57BL/6j female mice were placed in automated SF chambers with horizontally moving bars across the bottom of each cage at specified intervals to disrupt sleep. Mice were first subjected to either control (no bar movement), acute sleep fragmentation (ASF), or chronic sleep fragmentation (CSF) on a 12:12-h light/dark schedule. ASF involved a bar sweep every 120 s for 24 h, whereas CSF involved a bar sweep every 120 s for 12 h (during 12 L; resting period) over a period of 4 weeks. After exposure to these conditions, mice received an intraperitoneal injection of either phentolamine (5 mg/kg BW; an α-adrenergic receptor blocker), propranolol (5 mg/kg BW; a β-adrenergic receptor blocker), or vehicle (saline). Serum corticosterone concentration, brain and peripheral cytokine (IL1β, TNFα, and TGFβ) mRNA expression, and body mass were assessed. ASF and CSF significantly elevated serum corticosterone concentrations as well as cytokine mRNA expression levels compared with controls, and mice subjected to CSF had decreased body mass relative to controls. Mice subjected to CSF and treated with phentolamine or propranolol had a greater propensity for a decrease in cytokine gene expression compared with ASF, but effects were tissue-specific. Taken together, these results suggest that both α- and β-adrenergic receptors contribute to the SNS mediation of inflammatory responses, and adrenergic antagonists may effectively mitigate tissue-specific SF-mediated inflammation.

Beyond Homeostasis: Potassium and Pathogenesis during Bacterial Infections

Potassium is an essential mineral nutrient required by all living cells for normal physiological function. Therefore, maintaining intracellular potassium homeostasis during bacterial infection is a requirement for the survival of both host and pathogen. However, pathogenic bacteria require potassium transport to fulfill nutritional and chemiosmotic requirements, and potassium has been shown to directly modulate virulence gene expression, antimicrobial resistance, and biofilm formation. Host cells also require potassium to maintain fundamental biological processes, such as renal function, muscle contraction, and neuronal transmission; however, potassium flux also contributes to critical immunological and antimicrobial processes, such as cytokine production and inflammasome activation. Here, we review the role and regulation of potassium transport and signaling during infection in both mammalian and bacterial cells and highlight the importance of potassium to the success and survival of each organism.

Optogenetic activation of local colonic sympathetic innervations attenuates colitis by limiting immune cell extravasation

The sympathetic nervous system is composed of an endocrine arm, regulating blood adrenaline and noradrenaline, and a local arm, a network of fibers innervating immune organs. Here, we investigated the impact of the local arm of the SNS in an inflammatory response in the colon. Intra-rectal insertion of an optogenetic probe in mice engineered to express channelrhodopsin-2 in tyrosine hydroxylase cells activated colonic sympathetic fibers. In contrast to systemic application of noradrenaline, local activation of sympathetic fibers attenuated experimental colitis and reduced immune cell abundance. Gene expression profiling showed decreased endothelial expression of the adhesion molecule MAdCAM-1 upon optogenetic stimulation; this decrease was sensitive to adrenergic blockers and 6-hydroxydopamine. Antibody blockade of MAdCAM-1 abrogated the optogenetic effect on immune cell extravasation into the colon and the pathology. Thus, sympathetic fibers control colonic inflammation by regulating immune cell extravasation from circulation, a mechanism likely relevant in multiple organs.

A Review of Inflammatory Bowel Disease: A Model of Microbial, Immune and Neuropsychological Integration

Objective: Inflammatory bowel diseases (IBDs) are complex chronic inflammatory disorders of the gastro-intestinal (GI) tract with uncertain etiology. IBDs comprise two idiopathic disorders: Crohn's disease (CD) and ulcerative colitis (UC). The aetiology, severity and progression of such disorders are still poorly understood but thought to be influenced by multiple factors (including genetic, environmental, immunological, physiological, psychological factors and gut microbiome) and their interactions. The overarching aim of this review is to evaluate the extent and nature of the interrelationship between these factors with the disease course. A broader conceptual and longitudinal framework of possible neuro-visceral integration, core microbiome analysis and immune modulation assessment may be useful in accurately documenting and characterizing the nature and temporal continuity of crosstalk between these factors and the role of their interaction (s) in IBD disease activity. Characterization of these interactions holds the promise of identifying novel diagnostic, interventions, and therapeutic strategies. Material and Methods: A search of published literature was conducted by exploring PubMed, EMBASE, MEDLINE, Medline Plus, CDSR library databases. Following search terms relating to key question were set for the search included: "Inflammatory bowel diseases," "gut microbiota," "psychological distress and IBD," "autonomic reactivity and IBD," "immune modulation," "chronic inflammation," "gut inflammation," "enteric nervous system," "gut nervous system," "Crohn's disease," "Ulcerative colitis", "depression and IBD", "anxiety and IBD", "quality of life in IBD patients," "relapse in IBDs," "remission in IBDs," "IBD disease activity," "brain-gut-axis," "microbial signature in IBD," "validated questionnaires in IBD," "IBD activity indices," "IBD aetiology," "IBDs and stress," "epidemiology of IBDs", "autonomic nervous system and gut inflammation", "IBD and environment," "genetics of IBDs," "pathways of immune response in IBDs," "sleep disturbances in IBD," "hypothalamic-pituitary-adrenal axis (HPA)," "sympatho-adrenal axis," "CNS and its control of gut function" "mucosal immune response," "commensal and pathogenic bacteria in the gut," "innate and adaptive immunity." Studies evaluating any possible associations between gut microbiome, psychological state, immune modulation, and autonomic function with IBDs were identified. Commonly cited published literatures with high quality research methodology/results and additional articles from bibliographies of recovered papers were examined and included where relevant. Results: Although there is a substantial literature identifying major contributing factors with IBD, there has been little attempt to integrate some factors over time and assess their interplay and relationship with IBD disease activity. Such contributing factors include genetic and environmental factors, gut microbiota composition and function, physiological factors, psychological state and gut immune response. Interdependences are evident across psychological and biological factors and IBD disease activity. Although from the available evidence, it is implausible that a single explanatory model could elucidate the interplay between such factors and the disease course as well as the sequence of the effect during the pathophysiology of IBD. Conclusion: Longitudinal monitoring of IBD patients and integrating data related to the contributing/risk factors including psychological state, physiological conditions, inflammatory/immune modulations, and microbiome composition/function, could help to explain how major factors associate and interrelate leading to exacerbation of symptoms and disease activity. Identifying the temporal trajectory of biological and psychosocial disturbances may also help to assess their effects and interdependence on individuals' disease status. Moreover, this allows greater insight into understanding the temporal progressions of subclinical events as potential ground for disease severity in IBD. Furthermore, understanding the interaction between these risk factors may help better interventions in controlling the disease, reducing the costs related to disease management, further implications for clinical practice and research approaches in addition to improving patients' mental health and quality of life.

Assessment of cytokines, microRNA and patient related outcome measures in conversion disorder/functional neurological disorder (CD/FND): The CANDO clinical feasibility study

BACKGROUND

Conversion disorder/functional neurological disorder (CD/FND) occurs often in neurological settings and can lead to long-term distress, disability and demand on health care services. Systemic low-grade inflammation might play a role, however, the pathogenic mechanism is still unknown.

AIM

1) To explore the feasibility to establish and assess a cohort of CD/FND with motor symptoms, involving persons with lived experience (PPI). 2) To generate proof of concept regarding a possible role for cytokines, microRNA, cortisol levels and neurocognitive symptoms in patients with motor CD/FND.

METHOD

Feasibility study.

RESULTS

The study showed active involvement of patients despite high clinical illness burden and disability, neurocognitive symptoms, childhood adverse experiences (ACE) and current life events. The study provided valuable knowledge regarding the feasibility of conducting a study in these patients that will inform future study phases. In the sample there were elevated levels of IL6, IL12, IL17A, IFNg, TNFa and VEGF-a, suggesting systemic low-grade inflammation. Also, microRNAs involved in inflammation and vascular inflammation were correlated with TNFa and VEGFa respectively, suggesting proof of concept for an epigenetic mechanism. Owing to the COVID-19 outbreak, the patient sample was limited to 15 patients.

CONCLUSION

It is a novelty that this study is conducted in the clinical setting. This innovative, translational study explores stress-related SLI in CD/FND patients and the feasibility of a larger project aiming to develop new treatments for this vulnerable population. Given the positive findings, there is scope to conduct further research into the mechanism of disease in CD/FND.

Proliferative Glomerulonephritis: Risk Factor for Hypertension in Lupus

Studies report a high prevalence of hypertension in lupus, reaching up to 74%. The incidence of hypertension in SLE patients is increased with the severity of the kidney damage. This work was carried out with the objective of determining the prevalence of hypertension in lupus nephritis and to seek the existence of an association between the presence of a proliferative glomerulonephritis and hypertension. Patients and Methods. This was a case-control study, carried out in the nephrology department of the Aristide Le Dantec University Hospital in Dakar. All records of patients with lupus nephritis over a 10-year period, from January 01, 2007, to December 31, 2016, were included. Results. During the study period, out of 64 lupus nephritis records collected, 28 patients had hypertension, for a hospital prevalence of 43.75%. The mean age of the patients was 30.64 years ± 10.44. There were 24 women and 4 men. The mean systolic blood pressure was 156 mmHg (110–220) and the mean diastolic blood pressure was 100 mmHg (80–130). The mean serum creatinine was 29.48 mg/l ± 24.99. The mean proteinuria was 4.50 g/24 h ± 2.87. Hypertriglyceridemia was observed in one patient. Hypercholesterolemia was present in 3 patients. HDL levels were normal in all patients and elevated LDL levels were noted in all 4 patients. None of our patients had diabetes. Class III was found in 11 cases, class IV in 14 cases, pure class V in 2 cases, and class II in 1 case. Hypertension was associated with the presence of proliferative glomerulonephritis (odds ratio, 7.45; 95% CI, 1.9 to 29.1; p=0.002). Conclusion. Hypertension is common in lupus nephritis. The presence of a proliferative glomerulonephritis is a risk factor for the development of arterial hypertension. Screening and adequate management of hypertension are essential for the prevention of the progression of chronic kidney disease in lupus.

Autonomic and cholinergic mechanisms mediating cardiovascular and temperature effects of donepezil in conscious mice

Donepezil is a centrally acting acetylcholinesterase (AChE) inhibitor with therapeutic potential in inflammatory diseases; however, the underlying autonomic and cholinergic mechanisms remain unclear. Here, we assessed effects of donepezil on mean arterial pressure (MAP), heart rate (HR), HR variability, and body temperature in conscious adult male C57BL/6 mice to investigate the autonomic pathways involved. Central versus peripheral cholinergic effects of donepezil were assessed using pharmacological approaches including comparison with the peripherally acting AChE inhibitor, neostigmine. Drug treatments included donepezil (2.5 or 5 mg/kg sc), neostigmine methyl sulfate (80 or 240 μg/kg ip), atropine sulfate (5 mg/kg ip), atropine methyl bromide (5 mg/kg ip), or saline. Donepezil, at 2.5 and 5 mg/kg, decreased HR by 36 ± 4% and 44 ± 3% compared with saline (n = 10, P < 0.001). Donepezil, at 2.5 and 5 mg/kg, decreased temperature by 13 ± 2% and 22 ± 2% compared with saline (n = 6, P < 0.001). Modest (P < 0.001) increases in MAP were observed with donepezil after peak bradycardia occurred. Atropine sulfate and atropine methyl bromide blocked bradycardic responses to donepezil, but only atropine sulfate attenuated hypothermia. The pressor response to donepezil was similar in mice coadministered atropine sulfate; however, coadministration of atropine methyl bromide potentiated the increase in MAP. Neostigmine did not alter HR or temperature, but did result in early increases in MAP. Despite the marked bradycardia, donepezil did not increase normalized high-frequency HR variability. We conclude that donepezil causes marked bradycardia and hypothermia in conscious mice via the activation of muscarinic receptors while concurrently increasing MAP via autonomic and cholinergic pathways that remain to be elucidated.

Das gestresste Immunsystem und Autoimmunität

Über einen möglichen Zusammenhang zwischen psychologischem Stress, Immunsystem und Autoimmunität wird schon lange debattiert. Erkenntnisse aus der Grundlagen- und epidemiologischen Forschung, die das Verständnis für diesen komplexen Zusammenhang erhöhen werden in dieser kurzen Übersicht zusammengestellt. Zunächst werden bekannte anatomisch-physiologische Grundlagen für einen Zusammenhang zwischen psychologischem Stress und Immunsystem dargestellt. Es wird beschrieben, dass die Interaktion zwischen Gehirn über autonomes Nervensystem und Hormonsystem bis zur Immunzelle mit entsprechenden Rezeptoren für Neurotransmitter und Hormone mittlerweile bis auf die molekulare Ebene gut beschrieben ist. Im Rahmen der akuten Stressreaktion treten charakteristische Veränderungen im Immunsystem auf, die ebenfalls gut dokumentiert sind. In einem zweiten Teil wird dann beschrieben welche Veränderungen im Rahmen einer chronischen Stressbelastung am Immunsystem auftreten können und zuletzt wird diskutiert inwiefern diese Veränderungen auch für pathophysiologische Zustände des Immunsystems, z. B. im Rahmen von Autoimmunerkrankungen, relevant sein könnten. Zusammenfassend führt akuter Stress, im Sinne der optimalen Vorbereitung einer fight&flight Situation, zu einer Steigerung der Immunfunktion v. a. der humoralen Immunität, wohingegen die Auswirkungen von chronischem Stress weniger klar definiert sind und es eher zu einer Immundysregulation mit verminderter basaler Immunfunktion, v. a. der zytotoxischen Funktion aber einer gesteigerten Reaktion nach Aktivierung, v. a. im angeborenen Immunschenkel kommt. Epidemiologische Daten belegen gut, dass chronischer Stress zu einer erhöhten Suzeptibilität für Autoimmunerkrankungen führt. Erste klinische Anwendungen, wie beispielsweise die gezielte neuronale Stimulation des N. vagus sind in Erprobung, für einen breiteren klinischen Einsatz sollten aber die biologischen Netzwerkstrukturen noch besser verstanden werden, um die besten Angriffspunkte zu finden.

Childhood Trauma in Adult Depressive and Anxiety Disorders: An Integrated Review on Psychological and Biological Mechanisms in the NESDA Cohort

BACKGROUND

Childhood trauma (CT) has adverse consequences on mental health across the lifespan. The understanding of how CT increases vulnerability for psychiatric disorders is growing. However, lack of an integrative approach to psychological and biological mechanisms of CT hampers further advancement. This review integrates CT findings across explanatory levels from a longitudinal adult cohort - the Netherlands Study of Depression and Anxiety (NESDA).

METHODS

We reviewed all studies (k = 37) from the NESDA cohort (n = 2981) published from 2009 to 2020 containing CT findings related to psychopathology and potential psychological and biological mechanisms of CT.

RESULTS

CT was associated with a higher risk of anxiety and depressive disorders with the strongest associations in the comorbid group. CT predicted the onset of these disorders, recurrence, and poorer outcomes (more comorbidity and chronicity). CT was associated with maladaptive personality characteristics and cognitions (e.g., higher neuroticism and negative self-associations), mild stress systems dysregulations (heightened levels of cortisol and inflammation), advanced biological aging (increased epigenetic aging and telomere attrition), poorer lifestyle (higher smoking rate and body mass index), somatic health decline (e.g., increased metabolic syndrome dysregulations), and brain alterations (e.g., reduced mPFC volume and increased amygdala reactivity).

LIMITATIONS

Literature review of one cohort using mixed analytical approaches.

CONCLUSION

CT impacts the functioning of the brain, mind, and body, which together may contribute to a higher vulnerability for affective disorders. It is essential to employ an integrative approach combining different sources of data to understand the mechanisms of CT better.

Systemic inflammation in patients with Takotsubo syndrome: a review of mechanistic and clinical implications

Over recent decades, systemic inflammation  as  quantified  with  inflammation  markers  or  indices has been extensively  investigated  in the setting of  various  cardiovascular  conditions  including heart failure (HF),  acute coronary syndromes (ACS). In contrast, systemic inflammation  in patients with  takotsubo syndrome (TTS) has been an underrated  phenomenon in clinical practice. On the other hand, experimental and clinical data  have been  rapidly  accumulating  in the recent years  regarding   pathogenetic, prognostic as well as therapeutic implications of  systemic inflammation in TTS.  Accordingly, the present article  aims to provide a general perspective  on mechanistic and  clinical aspects of  systemic  inflammation in the setting of  TTS.

Increased extracellular water measured by bioimpedance analysis and increased serum levels of atrial natriuretic peptide in polymyalgia rheumatica patients : Signs of volume overload

BACKGROUND

Water retention is a typical feature of acute inflammatory episodes, chiefly implemented by the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis. This is an important compensatory mechanism counteracting expected water loss, e.g., due to sweating. Both the SNS and HPA axis are activated in polymyalgia rheumatica (PMR). As retention mechanisms may similarly apply in this disease, we hypothesized increased water retention in PMR.

METHODS

Using bioimpedance analysis body composition was investigated in 64 healthy controls and 32 treatment-naive PMR patients. All PMR patients satisfied the 2012 EULAR/ACR classification criteria for PMR. 32 PMR patients were tested before and after 7 days of glucocorticoid-based therapy. Serum levels of pro-atrial natriuretic peptide (proANP) were investigated in all PMR patients and 15 healthy controls.

RESULTS

Extracellular water (ECW) was markedly higher in PMR patients than in controls (mean ± SD: 49.1 ± 6.0% versus 36.3 ± 2.5% of total body water, p < 0.001). Patients with PMR demonstrated significantly higher serum levels of proANP compared to controls. Even before glucocorticoid treatment was initiated, systolic and diastolic blood pressure were higher in PMR patients compared to controls. Extracellular water levels did not change in PMR patients upon 7 days of intensified treatment.

CONCLUSION

This study demonstrated increased extracellular water and elevated serum levels of proANP as signs of fluid overload in patients with PMR. Volume changes are imprinted as long-lasting mechanisms as water distribution is not affected by short-term anti-inflammatory therapy.

Effects of mirror therapy on oedema, pain and functional activities in patients with poststroke shoulder-hand syndrome: A randomized controlled trial

OBJECTIVES

To study the effectiveness of mirror therapy along with a Stroke rehabilitation program on oedema, pain intensity and functional activities in patients with shoulder-hand syndrome (SHS) after stroke.

DESIGN

Randomized controlled trial.

SETTINGS

Out-patient rehabilitation center.

METHODS

Thirty-eight SHS patients after stroke, were randomly allocated into two groups; both the groups received a 4-week stroke rehabilitation program, 30 min a day for 5 days a week. Control group patients performed all the exercises of stroke rehabilitation program, while directly visualizing their both limbs. Experimental group patients performed same exercises of stroke rehabilitation program in front of the mirror.

OUTCOME MEASURES

Oedema (figure-of-eight measurement method), pain intensity (0-10 Numeric Pain Rating Scale [0-10 NPRS]), functional activities (Functional Independence Measure [FIM]).

RESULTS

After intervention, both groups showed statistically significant (p < 0.05) improvement for all measures (oedema measurement, 0-10 NPRS and FIM). Improvements were more significant (p < 0.05) in the experimental group with mirror therapy for all three measures compared to the control group. Mean differences between groups were 1.40 cm for oedema measurement, 0.87 for NPRS score and 12.20 for FIM score. At 2-week follow-up, the improvements were sustained.

CONCLUSION

The current study may indicate mirror therapy as an effective central neuromodulatory rehabilitative program to reduce pain, improves functional activities. More distinctively, this preliminary study suggests a decrease in oedema by mirror therapy for SHS after stroke. Improvement of upper limb in SHS after stroke will be more perceptible with the decrease in oedema, being the characteristic sign, following mirror therapy. Clinically, patients during their daily functional activities, shall be more confident to use their upper limb following mirror therapy after reduction in oedema along with pain.

Perceived stress is linked to heightened biomarkers of inflammation via diurnal cortisol in a national sample of adults

Exposure to and perceptions of stress have been associated with altered systemic inflammation, but the intermediate processes by which stress links to inflammation are not fully understood. Diurnal cortisol slopes were examined as a pathway by which self-reported psychosocial stress is associated with inflammation [i.e., C-reactive protein (CRP), interleukin-6 (IL-6), fibrinogen, E-Selectin, and Intercellular Adhesion Molecule-1 (ICAM-1)] in a large sample of adults (the Midlife in the US study; N = 914; 55.9% female; aged 34-84 years). Structural equation modeling indicated that perceived psychological stress was associated with flattened diurnal cortisol slopes and flatter diurnal cortisol slopes were, in turn, associated with heightened inflammation in these cross-sectional analyses (index of indirect pathway, ω = 0.003, 95% CI [0.001, 0.004], ωSTD = 0.027; with covariates, ω = 0.001, [0.0002, 0.002], ωSTD = 0.011). A similar indirect effect was evident for self-reported traumatic life events (ω = 0.007, [0.004, 0.012], ωSTD = 0.030); however, inclusion of covariates (i.e., age, gender, race, ethnicity, body mass index, and other factors associated with physical health) accounted for this finding (ω = 0.001, [-0.001, 0.004], ωSTD = 0.005). These results support an allostatic load model of psychosomatic health, in which cortisol (along with other stress-responsive signaling molecules) is a necessary component for understanding links between stress exposure, perceived stress, and immune functioning.

Intermittent Lipopolysaccharide Exposure Significantly Increases Cortical Infarct Size and Impairs Autophagy

Globally, stroke is a leading cause of death and disability. Traditional risk factors like hypertension, diabetes, and obesity do not fully account for all stroke cases. Recent infection is regarded as changes in systemic immune signaling, which can increase thrombosis formation and other stroke risk factors. We have previously shown that administration of lipopolysaccharide (LPS) 30-minutes prior to stroke increases in infarct volume. In the current study, we found that animals intermittently exposed to LPS have larger cortical infarcts when compared to saline controls. To elucidate the mechanism behind this phenomenon, several avenues were investigated. We observed significant upregulation of tumor necrosis factor-alpha (TNF-α) mRNA, especially in the ipsilateral hemisphere of both saline and LPS exposed groups compared to sham surgery animals. We also observed significant reductions in expression of genes involved in autophagy in the ipsilateral hemisphere of LPS stroke animals. In addition, we assessed DNA methylation of autophagy genes and observed a significant increase in the ipsilateral hemisphere of LPS stroke animals. Intermittent exposure to LPS increases cortical infarct volume, downregulates autophagy genes, and induces hypermethylation of the corresponding CpG islands. These data suggest that intermittent immune activation may deregulate epigenetic mechanisms and promote neuropathological outcomes after stroke.

Establishing low-density lipoprotein apheresis tolerability in patients with prior anaphylactoid reactions to lipoprotein apheresis using magnesium sulfate

BACKGROUND

Lipoprotein apheresis (LA) tolerability is a key factor for the utilization of this therapy. Common reactions to LA are hypotension and nausea. Serious reactions include severe hypotension and anaphylactoid reactions (0.13%-1.3% and 0.2%-0.4%, respectively). The bradykinin response drives these reactions and can worsen with the use of angiotensin-converting-enzyme inhibitors. Efforts to mitigate these reactions are necessary for the tolerability of LA with a dextran sulfate-adsorption (DSA) system.

MATERIALS AND METHODS

In an effort to increase apheresis tolerability, seven patients at The University of Kansas, Department of Clinical Pharmacology, who had prior anaphylactoid reactions (defined as general cutaneous flushing, nausea/vomiting, tongue swelling, lightheadedness, and hypotension) to the DSA despite pharmacologic intervention, were treated with pre-LA intravenous magnesium adapted from a protocol developed by co-author Eliaz. This protocol consists of 1.5 g of magnesium sulfate administered over 45 minutes. All seven patients were treated with intravenous magnesium sulfate immediately before LA.

RESULTS

No episodes of anaphylactoid reactions during LA have been reported to date.

CONCLUSIONS

Magnesium infusion before DSA can be utilized to establish tolerability in patients with prior anaphylactoid reactions to LA. Proposed mechanisms include temporary stabilization of the negative-positive interactions of the dextran sulfate filter leading to a reduction of circulating bradykinin, reduction of nitric oxide, and reduction of the sympathetic response to LA.

Baroreceptor Modulation of the Cardiovascular System, Pain, Consciousness, and Cognition

Baroreceptors are mechanosensitive elements of the peripheral nervous system that maintain cardiovascular homeostasis by coordinating the responses to external and internal environmental stressors. While it is well known that carotid and cardiopulmonary baroreceptors modulate sympathetic vasomotor and parasympathetic cardiac neural autonomic drive, to avoid excessive fluctuations in vascular tone and maintain intravascular volume, there is increasing recognition that baroreceptors also modulate a wide range of non-cardiovascular physiological responses via projections from the nucleus of the solitary tract to regions of the central nervous system, including the spinal cord. These projections regulate pain perception, sleep, consciousness, and cognition. In this article, we summarize the physiology of baroreceptor pathways and responses to baroreceptor activation with an emphasis on the mechanisms influencing cardiovascular function, pain perception, consciousness, and cognition. Understanding baroreceptor-mediated effects on cardiac and extra-cardiac autonomic activities will further our understanding of the pathophysiology of multiple common clinical conditions, such as chronic pain, disorders of consciousness (e.g., abnormalities in sleep-wake), and cognitive impairment, which may result in the identification and implementation of novel treatment modalities. © 2021 American Physiological Society. Compr Physiol 11:1373-1423, 2021.

Adrenergic signalling in osteoarthritis

Adrenoceptors (ARs) mediate the effects of the sympathetic neurotransmitters norepinephrine (NE) and epinephrine (E) in the human body and play a central role in physiologic and pathologic processes. Therefore, ARs have long been recognized as targets for therapeutic agents, especially in the field of cardiovascular medicine. During the past decades, the contribution of the sympathetic nervous system (SNS) and particularly of its major peripheral catecholamine NE to the pathogenesis of osteoarthritis (OA) attracted growing interest. OA is the most common degenerative joint disorder worldwide and a disease of the whole joint. It is characterized by progressive degradation of articular cartilage, synovial inflammation, osteophyte formation, and subchondral bone sclerosis mostly resulting in chronic pain. The subchondral bone marrow, the periosteum, the synovium, the vascular meniscus and numerous tendons and ligaments are innervated by tyrosine hydroxylase-positive (TH+) sympathetic nerve fibers that release NE into the synovial fluid and cells of all abovementioned joint tissues express at least one out of nine AR subtypes. During the past decades, several in vitro studies explored the AR-mediated effects of NE on different cell types in the joint. So far, only a few studies used animal OA models to investigate the contribution of distinct AR subtypes to OA pathogenesis in vivo. This narrative review shortly summarizes the current background knowledge about ARs and their signalling pathways at first. In the second part, we focus on recent findings in the field of NE-induced AR-mediated signalling in different joint tissues during OA pathogenesis and at the end, we will delineate the potential of targeting the adrenergic signalling for OA prevention or treatment. We used the PubMed bibliographic database to search for keywords such as 'joint' or 'cartilage' or 'synovium' or 'bone' and 'osteoarthritis' and/or 'trauma' and 'sympathetic nerve fibers' and/or 'norepinephrine' and 'adrenergic receptors / adrenoceptors' as well as 'adrenergic therapy'.

Ghrelin as an Anti-Sepsis Peptide: Review

Sepsis continues to produce widespread inflammation, illness, and death, prompting intensive research aimed at uncovering causes and therapies. In this article, we focus on ghrelin, an endogenous peptide with promise as a potent anti-inflammatory agent. Ghrelin was discovered, tracked, and isolated from stomach cells based on its ability to stimulate release of growth hormone. It also stimulates appetite and is shown to be anti-inflammatory in a wide range of tissues. The anti-inflammatory effects mediated by ghrelin are a result of both the stimulation of anti-inflammatory processes and an inhibition of pro-inflammatory forces. Anti-inflammatory processes are promoted in a broad range of tissues including the hypothalamus and vagus nerve as well as in a broad range of immune cells. Aged rodents have reduced levels of growth hormone (GH) and diminished immune responses; ghrelin administration boosts GH levels and immune response. The anti-inflammatory functions of ghrelin, well displayed in preclinical animal models of sepsis, are just being charted in patients, with expectations that ghrelin and growth hormone might improve outcomes in patients with sepsis.

Relationship of Cardiac Autonomic Modulation with Cardiovascular Parameters in Adults, According to Body Mass Index and Physical Activity

This study aimed to analyze the relationship between cardiac autonomic modulation (CAM) and cardiovascular parameters (blood pressure and resting heart rate) in a sample of 256 adults, grouped by body mass index and sufficient moderate-to-vigorous physical activity (≥150 min/week). The sample showed different cardiovascular parameters and CAM according to body mass index, but not according to physical activity. Adults who are overweight and physically active presented higher relationship between CAM and blood pressure than those who are insufficiently active, similarly to normal weight groups. Recommended levels of physical activity may play an important role in the relationship of HRV with cardiovascular parameters in overweight adults, regardless of sex, age, socioeconomic level, and central fat. Trial registration: Registered at ClinicalTrials.gov (NCT03986879). Graphical abstract.

Adipokines and Autoimmunity in Inflammatory Arthritis

Adipokines are adipose tissue-derived factors not only playing an important role in metabolism but also influencing other central processes of the body, such as inflammation. In autoimmune diseases, adipokines are involved in inflammatory pathways affecting different cell types. Many rheumatic diseases belong to the group of autoimmune diseases, for example rheumatoid arthritis (RA) and psoriatic arthritis. Due to the autoimmune responses, a chronic inflammatory milieu develops, which affects the whole body, including adipose tissue. Metabolic alterations such as obesity influence inflammatory responses in autoimmune diseases. Adipokines are bioactive mediators mainly produced by adipose tissue. Due to alterations of systemic adipokine levels, their role as biomarkers with diagnostic potential has been suggested in the context of rheumatic diseases. In the affected joints of RA patients, different synoviocytes but also osteoclasts, osteoblasts, and chondrocytes produce several adipokines, contributing to the unique inflammatory microenvironment. Adipokines have been shown to be potent modulatory effectors on different cell types of the immune system but also local cells in synovial tissue, cartilage, and bone. This review highlights the most recent findings on the role of adipokines in the pathophysiology of inflammatory arthritis with a distinct focus on RA in the quickly developing research field.

RAISE study protocol: a cross-sectional, multilevel, neurobiological study of resilience after individual stress exposure

INTRODUCTION

This paper describes the protocol for an ongoing project funded by the Royal Society, the Resilience After Individual Stress Exposure (RAISE) study; which aims to examine the factors and mechanisms that facilitate resilient functioning after childhood adversity (CA).

METHODS AND ANALYSIS

We aim to recruit up to 200 participants. We will use dimension reduction techniques (principal component analysis) on standard-normally transformed individual parameters of mental health, social functioning and CA to calculate a composite measure of adaptive (ie, 'resilient') psychosocial functioning. To examine the neuroimmune responses to stress and their relationship with the brain and social environment, we will use a well validated functional MRI task; the Montreal imaging stress task and venepuncture. We will run group or dimensional comparisons in multiple levels of biological and psychological outcomes, as well as mediation and moderation analyses to study how key biological systems (ie, the hypothalamic-pituitary-adrenal axis and the immune system) interrelate and interact with brain function and social influences in order to facilitate resilient functioning after CA. We hypothesise that resilient functioning will be facilitated by reduced morning cortisol and cytokine levels before and after the stressor and improved neural responses to such stress, as well as increased gray matter volume in the hippocampus and prefrontal cortex, enhanced inhibitory control and emotion regulation, and more friendship and family support.

ETHICS AND DISSEMINATION

This study has been reviewed and given favourable opinion by the National Research Ethics Service, NRES Committee East of England-Cambridge Central and external reviewers from the Royal Society (RGF\R1\180064 and RGF\EA\180029). The results of the RAISE study will be disseminated through (1) publications in scientific peer reviewed journals, (2) presentations on relevant scientific conferences and meetings, (3) publications and presentations for the general public and (4) through social media.

Inflammatory Mediators and Pain in Endometriosis: A Systematic Review

BACKGROUND

pain is one of the main symptoms of endometriosis and it has a deleterious effect on a patients' personal and social life. To date, the clinical management of pain includes prolonged medication use and, in some cases, surgery, both of which are disruptive events for patients. Hence, there is an urgency for the development of a sufficient non-invasive medical treatment. Inflammation is one of the causative factors of pain in endometriosis. It is well established that inflammatory mediators promote angiogenesis and interact with the sensory neurons inducing the pain signal; the threshold of pain varies and it depends on the state and location of the disease. The inhibition of inflammatory mediators' synthesis might offer a novel and effective treatment of the pain that is caused by inflammation in endometriosis.

OBJECTIVES

patients with endometriosis experience chronic pelvic pain, which is moderate to severe in terms of intensity. The objective of this systematic review is to highlight the inflammatory mediators that contribute to the induction of pain in endometriosis and present their biological mechanism of action. In addition, the authors aim to identify new targets for the development of novel treatments for chronic pelvic pain in patients with endometriosis.

DATA SOURCES

three databases (PubMed, Scopus, and Europe PMC) were searched in order to retrieve articles with the keywords 'inflammation, pain, and endometriosis' between the review period of 1 January 2016 to 31 December 2020. This review has been registered with PROSPERO (registry number: CRD42020171018). Eligibility Criteria: only original articles that presented the regulation of inflammatory mediators and related biological molecules in endometriosis and their contribution in the stimulation of pain signal were included.

DATA EXTRACTION

two authors independently extracted data from articles, using predefined criteria.

RESULTS

the database search yielded 1871 articles, which were narrowed down to 56 relevant articles of interest according to the eligibility criteria.

CONCLUSIONS

inflammatory factors that promote angiogenesis and neuroangiogenesis are promising targets for the treatment of inflammatory pain in endometriosis. Specifically, CXC chemokine family, chemokine fractalkine, and PGE2 have an active role in the induction of pain. Additionally, IL-1β appears to be the primary interleukin (IL), which stimulates the majority of the inflammatory factors that contribute to neuroangiogenesis along with IL-6. Finally, the role of Ninj1 and BDNF proteins needs further investigation.

Neuronal regulation of immunity: why, how and where?

Neuroimmunology is one of the fastest-growing fields in the life sciences, and for good reason; it fills the gap between two principal systems of the organism, the nervous system and the immune system. Although both systems affect each other through bidirectional interactions, we focus here on one direction - the effects of the nervous system on immunity. First, we ask why is it beneficial to allow the nervous system any control over immunity? We evaluate the potential benefits to the immune system that arise by taking advantage of some of the brain's unique features, such as its capacity to integrate and synchronize physiological functions, its predictive capacity and its speed of response. Second, we explore how the brain communicates with the peripheral immune system, with a focus on the endocrine, sympathetic, parasympathetic, sensory and meningeal lymphatic systems. Finally, we examine where in the brain this immune information is processed and regulated. We chart a partial map of brain regions that may be relevant for brain-immune system communication, our goal being to introduce a conceptual framework for formulating new hypotheses to study these interactions.

Role of Adiponectin in the Pathogenesis of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic chronic inflammatory autoimmune joint disease, characterized by progressive articular damage and joint dysfunction. One of the symptoms of this disease is persistent inflammatory infiltration of the synovial membrane, the principle site of inflammation in RA. In the affected conditions, the cells of the synovial membrane, fibroblast-like synoviocytes and macrophage-like synovial cells, produce enzymes degrading cartilage and underlining bone tissue, as well as cytokines increasing the infiltration of immune cells. In patients with RA, higher levels of adiponectin are measured in the serum and synovial fluid. Adiponectin, a secretory product that is mainly white adipose tissue, is a multifunctional protein with dual anti-inflammatory and pro-inflammatory properties. Several studies underline the fact that adiponectin can play an important pro-inflammatory role in the pathophysiology of RA via stimulating the secretion of inflammatory mediators. This narrative review is devoted to the presentation of recent knowledge on the role played by one of the adipokines produced by adipose tissue—adiponectin—in the pathogenesis of rheumatoid arthritis.

Withdrawal-associated injury site pain prevalence and correlates among opioid-using people who inject drugs in Vancouver, Canada

BACKGROUND

Pain can return temporarily to old injury sites during opioid withdrawal. The prevalence and impact of opioid withdrawal-associated injury site pain (WISP) in various groups is unknown.

METHODS

Using data from observational cohorts, we estimated the prevalence and correlates of WISP among opioid-using people who inject drugs (PWID). Between June and December 2015, data on WISP and opioid use behaviours were elicited from participants in three ongoing prospective cohort studies in Vancouver, Canada, who were aged 18 years and older and who self-reported at least daily injection of heroin or non-medical presciption opioids.

RESULTS

Among 631 individuals, 276 (43.7 %) had a healed injury (usually pain-free), among whom 112 (40.6 %) experienced WISP, representing 17.7 % of opioid-using PWID interviewed. In a multivariable logistic regression model, WISP was positively associated with having a high school diploma or above (Adjusted Odds Ratio [AOR] = 2.23, 95 % Confidence Interval [CI]: 1.31-3.84), any heroin use in the last six months (AOR = 2.00, 95 % CI: 1.14-3.57), feeling daily pain that required medication (AOR = 2.06, CI: 1.18-3.63), and negatively associated with older age at first drug use (AOR = 0.96, 95 % CI: 0.93-0.99). Among 112 individuals with WISP, 79 (70.5 %) said that having this pain affected their opioid use behaviour, of whom 57 (72.2 %) used more opioids, 19 (24.1 %) avoided opioid withdrawal, while 3 (3.8 %) no longer used opioids to avoid WISP.

CONCLUSIONS

WISP is prevalent among PWID with a previous injury, and may alter opioid use patterns. Improved care strategies for WISP are warrented.

Evidence of Long-range nerve pathways connecting and coordinating activity in secondary lymph organs

Background

Peripheral nerve reflexes enable organ systems to maintain long-term physiological homeostasis while responding to rapidly changing environmental conditions. Electrical nerve stimulation is commonly used to activate these reflexes and modulate organ function, giving rise to an emerging class of therapeutics called bioelectronic medicines. Dogma maintains that immune cell migration to and from organs is mediated by inflammatory signals (i.e. cytokines or pathogen associated signaling molecules). However, nerve reflexes that regulate immune function have only recently been elucidated, and stimulation of these reflexes for therapeutic effect has not been fully investigated.

Methods

We utilized both electrical and ultrasound-based nerve stimulation to activate nerve pathways projecting to specific lymph nodes. Tissue and cell analysis of the stimulated lymph node, distal lymph nodes and immune organs is then utilized to measure the stimulation-induced changes in neurotransmitter/neuropeptide concentrations and immune cellularity in each of these sites.

Results and conclusions

In this report, we demonstrate that activation of nerves and stimulated release of neurotransmitters within a local lymph node results in transient retention of immune cells (e.g. lymphocytes and neutrophils) at that location. Furthermore, such stimulation results in transient changes in neurotransmitter concentrations at distal organs of the immune system, spleen and liver, and mobilization of immune cells into the circulation. This report will enable future studies in which stimulation of these long-range nerve connections between lymphatic and immune organs can be applied for clinical purpose, including therapeutic modulation of cellularity during vaccination, active allergic response, or active auto-immune disease.

Spezielle Schmerztherapie bei rheumatischen Erkrankungen

Schmerz als Hauptsymptom vieler chronisch-entzündlicher Erkrankungen stellt für den Patienten, aber auch für den behandelnden Arzt besonders in seiner chronifizierten Form eine große Herausforderung dar. Es gibt leider keine „Wunderpille“ mit der man Schmerzen für jeden gleich zuverlässig beseitigen kann. Es gibt aber viele Ansätze pharmakologischer als auch nicht-pharmakologischer Art und deren Kombination, um für den einzelnen Patienten wirksame Behandlungsstrategien zu finden. Um diese Strategien für jeden Patienten individuell optimal festzulegen, bedarf es zum einen eines fundamentierten Wissens über das Spektrum zur Verfügung stehender Mittel, zum anderen aber auch Erkenntnis darüber, wie diese sinnvoll nach Art der vorliegenden Schmerzformen einzusetzen sind. In dieser Übersicht wird beides behandelt, mit einem Fokus auf die medikamentöse Therapie von Schmerzen bei entzündlich-rheumatischen Erkrankungen. Dabei wird herausgearbeitet, dass es für die in diesem Zusammenhang relevantesten Formen des Schmerzes, akut-entzündlich nozizeptiv, neuropathisch und durch periphere und zentrale Sensibilisierung chronifizierte Schmerzen, jeweils andere wirksame Konzepte gibt.

Tissue-Specific Role of Macrophages in Noninfectious Inflammatory Disorders

Chronic inflammation may not begin with local tissue disorders, such as hypoxia, but with the accumulation of critically activated macrophages in one site. The purpose of this review is to analyze the data reported in the scientific literature on the features of the functions of macrophages and their contributions to the development of pathology in various tissues during aseptic inflammation in obese subjects. In individuals with obesity, increased migration of monocytes from the peripheral blood to various tissues, the proliferation of resident macrophages and a change in the balance between alternatively activated anti-inflammatory macrophages (M2) and pro-inflammatory classically activated macrophages (M1) towards the latter have been observed. The primary cause of some metabolic pathologies has been precisely identified as the recruitment of macrophages with an altered phenotype, which is probably typical for many other pathologies. Recent studies have identified phenotypes, such as metabolically activated M (MMe), oxidized (Mox), hemoglobin-related macrophages (Mhem and MHb), M4 and neuroimmunological macrophages (NAM, SAM), which directly and indirectly affect energy metabolism. The high heterogeneity of macrophages in tissues contributes to the involvement of these cells in the development of a wide range of immune responses, including pathological ones. The replenishment of tissue-specific macrophages occurs at the expense of infiltrating monocyte-derived macrophages (MoMFs) in the pathological process. The origin of MoMFs from a general precursor retains their common regulatory mechanisms and similar sensitivity to regulatory stimuli. This makes it possible to find universal approaches to the effect on these cells and, as a consequence, universal approaches for the treatment of various pathological conditions.

Exploring the Effects of Osteopathic Manipulative Treatment on Autonomic Function Through the Lens of Heart Rate Variability

The osteopathic community has long hypothesized that the autonomic nervous system (ANS) represents one of the putative substrates through which osteopathic manipulative treatment (OMT) can improve body functions that have been altered by musculoskeletal alterations. Heart rate variability (HRV) is an important physiological measure of cardiac ANS activity. Emerging evidence suggests that OMT is associated with HRV changes that (i) are indicative of a larger cardiac vagal modulation, (ii) are independent from the part of the body needing treatment, (iii) occur even in the absence of musculoskeletal alterations. Yet, many questions remain unanswered, the duration of these effects and the specificity of HRV responses to different OMT techniques being perhaps the most critical. Therefore, this paper discusses prospects for future applications of HRV for the study of the influence of OMT on ANS function. Moreover, based on existing studies and preliminary data on the effects of OMT on HRV in specific pathological (hypertension) and physiological (stress exposure and recovery from sport competition) conditions that are commonly associated with increased sympathetic and/or decreased vagal activity, we propose that HRV analysis could be exploited to evaluate the effectiveness of OMT as a preventive or complementary strategy in clinical and non-clinical conditions characterized by ANS imbalance.

Association Between Inflammatory Mediators and Pulmonary Blood Flow in a Rabbit Model of Acute Pulmonary Embolism Combined With Shock

Background

The pro-inflammatory cytokines were detected in pulmonary embolism (PE) and non-pulmonary embolism (non-PE) tissues to explore the role of inflammation responses and their relationship with the pulmonary blood flow in a rabbit model of acute pulmonary embolism combined with shock.

Methods and Results

Nineteen rabbits were randomly divided into sham operation group (S group, n = 8) and massive PE (MPE group, n = 11). The MPE model was established by injecting the autologous blood clots into the main pulmonary artery of rabbit. Pulmonary angiography showed that the pulmonary circulation time was significantly prolonged in the MPE group, and pulmonary blood flow was attenuated at 120 min post PE. Hematoxylin–eosin (HE) staining revealed enhanced inflammatory cell infiltration around the pulmonary vessels in PE and non-PE tissues, and obvious edema on the perivascular region. Meanwhile, the expressions of inducible nitric oxide synthase (iNOS) and arginase 1 (Arg-1) in pulmonary vascular and alveolar tissues were significantly upregulated and the iNOS/Arg-1 ratio was significantly higher in the MPE group than in the S group. Moreover, the levels of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) were also significantly increased in PE and non-PE tissues, and interleukin-6 (IL-6) level was significantly increased in non-PE tissues in the MPE group as compared to the S group. Thromboxane A2 (TXA₂) and alpha smooth muscle actin (α-SMA) levels were significantly higher in both PE and non-PE tissues in the MPE group than in the S group.

Conclusion

Activation of inflammation mediators in PE and non-PE tissues might be one of the crucial factors responsible for pulmonary vasculature constriction and pulmonary blood flow attenuation in this MPE model.

Novel Insights into Beta 2 Adrenergic Receptor Function in the rd10 Model of Retinitis Pigmentosa

Background: In retinitis pigmentosa (RP), inherited rod death is followed by cone loss and blindness. Why cones die is still a matter of consideration. Here, we investigate the pathogenic role of the sympathetic transmission in the rd10 mouse model of RP. Methods: Retinal levels of beta adrenergic receptor (BAR) 2 and norepinephrine (NE) were measured. After administration of the BAR1/2 blocker propranolol or the hypoxia-inducible factor (HIF)-1 activator dimethyloxalylglycine (DMOG), retinal levels of HIF-1α, BAR2 or proteins involved in BAR2 desensitization were also measured. In DMOG treated mice, expression and localization of BAR2, inflammatory markers and cone arrestin were determined. Finally, rd10 mice were subjected to electroretinogram (ERG) analysis to assess rod and cone function. Results: In the rd10 retina, BAR2 overexpression and NE accumulation were found, with BAR2 immunoreactivity localized to Müller cells. BAR2 overexpression was likely due to desensitization defects. Upregulated levels of BAR2 were drastically reduced by propranolol that also restored desensitization defects. Due to the low level of HIF-1 consequent to the hyperoxic environment in the rd10 retina, we hypothesized a link between HIF-1 and BAR2. HIF-1α stabilization with DMOG resulted in i. increased HIF-1α accumulation, ii. decreased BAR2 levels, iii. restored desensitization processes, iv. reduced expression of inflammatory markers and v. increased cone survival without improved retinal function. Conclusions: Our results support a pathogenic role of the sympathetic system in RP that might help to understand why rd10 mice show a positive response to BAR blockers.

Anti-Inflammatory and Antiarrhythmic Effects of Beta Blocker in a Rat Model of Rheumatoid Arthritis

Background

Patients with rheumatoid arthritis are at twice the risk of ventricular arrhythmia and sudden cardiac death as the general population. We hypothesize that β‐blocker treatment of rheumatoid arthritis is antiarrhythmic by producing synergistic anticatecholaminergic and anti‐inflammatory effects.

Methods and Results

Collagen‐induced arthritis (CIA) was induced in Lewis rats by immunization with type II collagen in Freund's incomplete adjuvant. The treatment with propranolol (4 mg/kg) started on the first day of immunization. We evaluated the ventricular vulnerability to ventricular arrhythmia using in vivo programmed stimulation and performed ex vivo optical mapping to measure the electrical remodeling of the heart. The ventricular tissue was further processed for immunohistochemical staining and protein array analysis. The assessment of ventricular vulnerability showed that the number and duration of the induced ventricular arrhythmia episodes were increased in CIA rats, which were improved with propranolol treatment. The sympathovagal index and the plasma level of catecholamines significantly increased in CIA rats, whereas the use of propranolol attenuated sympathetic hyperactivity. In the optical mapping study, electrical remodeling, characterized by prolonged action potential duration, slow conduction velocity, and steepened action‐potential duration restitution, were noted in CIA rats and reversed in the propranolol‐treatment group. The propranolol treatment was associated with decreases in paw thickness, fewer inflammatory cell infiltrations in the heart, reduced levels of cardiac inflammatory cytokines, and less cardiac fibrosis as compared with the CIA group.

Conclusions

CIA increased ventricular arrhythmia vulnerability through sympathetic hyperinnervation and proarrhythmic ventricular electrophysiological remodeling. Treatment with propranolol in CIA rats was both anti‐inflammatory and antiarrhythmic.

Mazzola P, Souto EB, Chaud MV. Cachexia: Pathophysiology and Ghrelin Liposomes for Nose-to-Brain Delivery

Cachexia, a severe multifactorial condition that is underestimated and unrecognized in patients, is characterized by continuous muscle mass loss that leads to progressive functional impairment, while nutritional support cannot completely reverse this clinical condition. There is a strong need for more effective and targeted therapies for cachexia patients. There is a need for drugs that act on cachexia as a distinct and treatable condition to prevent or reverse excess catabolism and inflammation. Due to ghrelin properties, it has been studied in the cachexia and other treatments in a growing number of works. However, in the body, exogenous ghrelin is subject to very rapid degradation. In this context, the intranasal release of ghrelin-loaded liposomes to cross the blood-brain barrier and the release of the drug into the central nervous system may be a promising alternative to improve its bioavailability. The administration of nose-to-brain liposomes for the management of cachexia was addressed only in a limited number of published works. This review focuses on the discussion of the pathophysiology of cachexia, synthesis and physiological effects of ghrelin and the potential treatment of the diseased using ghrelin-loaded liposomes through the nose-to-brain route.

Interference with pancreatic sympathetic signaling halts the onset of diabetes in mice

The notably lobular distribution of immune lesions in type 1 diabetes (T1D) has been hypothesized to be the result of innervation within the pancreas. To investigate whether neuroimmune interactions could explain this phenomenon, we explored the impact of sympathetic signaling in the RIP-LCMV-GP mouse model of autoimmune diabetes. In this model, the CD8⁺ T cell attack on β cells replicates a key pathogenic feature of human T1D. We found that inhibition of α₁ adrenoceptors, ablation of sympathetic nerves, and surgical denervation all had a protective effect in this model, without affecting the systemic presence of β cell-reactive CD8⁺ T cells. In vivo multiphoton imaging revealed a local effect within pancreatic islets including limited infiltration of both macrophages and β cell-specific CD8⁺ T cells. Islet-resident macrophages expressed adrenoceptors and were responsive to catecholamines. Islet macrophages may therefore constitute a pivotal neuroimmune signaling relay and could be a target for future interventions in T1D.

Diabetes, and its treatment, as an effector of autonomic nervous system circuits and its functions

Diabetes increases the risk of cardiovascular complications, including heart failure, hypertension, and stroke. There is a strong involvement of autonomic dysfunction in individuals with diabetes that exhibit clinical manifestations of cardiovascular diseases (CVD). Still, the mechanisms by which diabetes and its treatments alter autonomic function and subsequently affect cardiovascular complications remain elusive. For this reason, understanding the brainstem circuits involved in sensing metabolic state(s) and enacting autonomic control of the cardiovascular system are important to develop more comprehensive therapies for individuals with diabetes at increased risk for CVD. We review how autonomic nervous system circuits change during these disease states and discuss their potential role in current pharmacotherapies that target diabetic states. Overall, this review proposes that the brainstem circuits provide an integrative sensorimotor network capable of responding to metabolic cues to regulate cardiovascular function and this network is modified by, and in turn affects, diabetes-induced CVD and its treatment.

Trauma of major surgery: A global problem that is not going away

Globally, a staggering 310 million major surgeries are performed each year; around 40 to 50 million in USA and 20 million in Europe. It is estimated that 1–4% of these patients will die, up to 15% will have serious postoperative morbidity, and 5–15% will be readmitted within 30 days. An annual global mortality of around 8 million patients places major surgery comparable with the leading causes of death from cardiovascular disease and stroke, cancer and injury. If surgical complications were classified as a pandemic, like HIV/AIDS or coronavirus (COVID-19), developed countries would work together and devise an immediate action plan and allocate resources to address it. Seeking to reduce preventable deaths and post-surgical complications would save billions of dollars in healthcare costs. Part of the global problem resides in differences in institutional practice patterns in high- and low-income countries, and part from a lack of effective perioperative drug therapies to protect the patient from surgical stress. We briefly review the history of surgical stress and provide a path forward from a systems-based approach. Key to progress is recognizing that the anesthetized brain is still physiologically ‘awake’ and responsive to the sterile stressors of surgery. New intravenous drug therapies are urgently required after anesthesia and before the first incision to prevent the brain from switching to sympathetic overdrive and activating secondary injury progression such as hyperinflammation, coagulopathy, immune activation and metabolic dysfunction. A systems-based approach targeting central nervous system-mitochondrial coupling may help drive research to improve outcomes following major surgery in civilian and military medicine.

Mild Inflammation in Healthy Males Induces Fatigue Mediated by Changes in Effective Connectivity Within the Insula

BACKGROUND

Systemic inflammation is associated with sickness behaviors such as low mood and fatigue. Activity patterns within the insula are suggested to coordinate these behaviors but have not been modeled. We hypothesized that mild systemic inflammation would result in changes in effective connectivity between the viscerosensory and the visceromotor regions of the insula.

METHODS

We used a double-blind, crossover design to randomize 20 male subjects to receive either a Salmonella typhi vaccine or a placebo saline injection at two separate sessions. All participants underwent a resting-state functional magnetic resonance scan 3 hours after injection. We determined behavioral and inflammatory changes, using the Profile of Mood States questionnaire and interleukin-6 levels. We extracted effective connectivity matrices between bilateral mid/posterior (viscerosensory) and anterior (visceromotor) insular cortices using spectral dynamic causal modeling. We applied parametric empirical Bayes and mediation analysis to determine a vaccination effect on effective connectivity and whether this mediated behavioral changes.

RESULTS

The vaccine condition was associated with greater interleukin-6 levels and greater fatigue 3 hours after the injection. Activity within the right mid/posterior insula increased the activity within the bilateral anterior insular regions. This connectivity was augmented by vaccination over a 99% posterior confidence threshold. The right mid/posterior insula-to-left anterior insula connectivity was significantly associated with fatigue and mediated the association between inflammation and increased fatigue scores.

CONCLUSIONS

These results demonstrate that increased effective connectivity between specific nodes of the insula can model and mediate the association between inflammation and fatigue in males.

Chronic Inflammation in the Context of Everyday Life: Dietary Changes as Mitigating Factors

The lifestyle adopted by most people in Western societies has an important impact on the propensity to metabolic disorders (e.g., diabetes, cancer, cardiovascular disease, neurodegenerative diseases). This is often accompanied by chronic low-grade inflammation, driven by the activation of various molecular pathways such as STAT3 (signal transducer and activator of transcription 3), IKK (IκB kinase), MMP9 (matrix metallopeptidase 9), MAPK (mitogen-activated protein kinases), COX2 (cyclooxigenase 2), and NF-Kβ (nuclear factor kappa-light-chain-enhancer of activated B cells). Multiple intervention studies have demonstrated that lifestyle changes can lead to reduced inflammation and improved health. This can be linked to the concept of real-life risk simulation, since humans are continuously exposed to dietary factors in small doses and complex combinations (e.g., polyphenols, fibers, polyunsaturated fatty acids, etc.). Inflammation biomarkers improve in patients who consume a certain amount of fiber per day; some even losing weight. Fasting in combination with calorie restriction modulates molecular mechanisms such as m-TOR, FOXO, NRF2, AMPK, and sirtuins, ultimately leads to significantly reduced inflammatory marker levels, as well as improved metabolic markers. Moving toward healthier dietary habits at the individual level and in publicly-funded institutions, such as schools or hospitals, could help improving public health, reducing healthcare costs and improving community resilience to epidemics (such as COVID-19), which predominantly affects individuals with metabolic diseases.

Neuro-Immunity Controls Obesity-Induced Pain

The prevalence of obesity skyrocketed over the past decades to become a significant public health problem. Obesity is recognized as a low-grade inflammatory disease and is linked with several comorbidities such as diabetes, circulatory disease, common neurodegenerative diseases, as well as chronic pain. Adipocytes are a major neuroendocrine organ that continually, and systemically, releases pro-inflammatory factors. While the exact mechanisms driving obesity-induced pain remain poorly defined, nociceptor hypersensitivity may result from the systemic state of inflammation characteristic of obesity as well as weight surplus-induced mechanical stress. Obesity and pain also share various genetic mutations, lifestyle risk factors, and metabolic pathways. For instance, fat pads are often found hyper-innervated and rich in immune cell types of multiple origins. These immunocytes release cytokines, amplifying nociceptor function, which, in turn, via locally released neuropeptides, sustain immunocytes' function. Here, we posit that along with mechanical stress stemming from extra weight, the local neuro-immune interplay occurring within the fat pads maintains the state of chronic low-grade inflammation and heightens sensory hypersensitivity. Overall, stopping such harmful neuro-immune crosstalk may constitute a novel pathway to prevent obesity-associated comorbidities, including neuronal hypersensitivity.

Posttraumatic stress disorder and breast cancer: Risk factors and the role of inflammation and endocrine function

A breast cancer diagnosis can be a life-changing and stressful experience that can lead to chronic mental health conditions such as posttraumatic stress disorder (PTSD). Greater than one-third of patients initially diagnosed with PTSD after a diagnosis of breast cancer continue to have persistent or worsening PTSD symptoms after 4 years. An emerging body of literature has indicated several key environmental and biological risk factors for PTSD among survivors of breast cancer. Well-recognized risk factors include having a history of childhood trauma, being nonwhite, obesity, younger age at the time of diagnosis, diagnosis with a higher stage of breast cancer, and short time since treatment. Of the emerging risk factors related to fear circuitry in the brain, 2 pathways of particular importance are the stress-driven activation of inflammatory pathways and the long-term effect of antiendocrine therapies. These central and peripheral responses during and after stress exposure are important because increased fear and anxiety can lead to the maintenance of PTSD and worse patient outcomes. Given the poor outcomes associated with PTSD and the high prevalence of breast cancer in women, more research to identify those women at heightened risk of PTSD after breast cancer is warranted to reduce the number of diagnoses and lessen the negative impact of this chronic mental health condition.

Alpha2B-Adrenergic Receptor Overexpression in the Brain Potentiate Air Pollution-induced Behavior and Blood Pressure Changes

Fine ambient particulate matter (PM2.5) is able to induce sympathetic activation and inflammation in the brain. However, direct evidence demonstrating an essential role of sympathetic activation in PM2.5-associated disease progression is lacking. We assess the contribution of α2B-adrenergic receptor (Adra2b) in air pollution-associated hypertension and behavioral changes in this study. Wild-type mice and Adra2b-transgenic mice overexpressing Adra2b in the brain (Adra2bTg) were exposed to concentrated PM2.5 or filtered air for 3 months via a versatile aerosol concentrator exposure system. Mice were fed with a high salt diet (4.0% NaCl) for 1 week at week 11 of exposure to induce blood pressure elevation. Intra-arterial blood pressure was monitored by radio-telemetry and behavior changes were assessed by open field, light-dark, and prepulse inhibition tests. PM2.5 exposure increased Adra2b in the brain of wild-type mice. Adra2b overexpression enhanced the anxiety-like behavior and high salt diet-induced blood pressure elevation in response to air pollution but not filtered air exposure. Adra2b overexpression induced upregulation of inflammatory genes such as TLR2, TLR4, and IL-6 in the brain exposed to PM2.5. In addition, there were increased frequencies of activated effector T cells and increased expression of oxidative stress-related genes, such as SOD1, NQO1, Nrf2, and Gclm in Adra2bTg mice compared with wild-type mice. Our results provide new evidence of distinct behavioral changes consistent with anxiety and blood pressure elevation in response to high salt intake and air pollution exposure, highlighting the importance of centrally expressed Adra2b in the vulnerability to air pollution exposure.

A positive feedback loop between alpha1-adrenoceptors and inflammatory cytokines in keratinocytes

A positive feedback loop between inflammatory cytokines and alpha₁-adrenoceptors (α₁-AR) (a target of the sympathetic nervous system neurotransmitter norepinephrine) influences inflammatory responses in immune cells. This cross-talk between the sympathetic nervous system and immune system may play a role in promoting chronic inflammation. Emerging evidence shows that α₁-AR interact with inflammatory cytokines in keratinocytes, and this epidermal adrenergic signalling may contribute to skin inflammatory responses following injury, disease or stress. In this study, utilizing an in vitro approach, we hypothesized that α₁-AR interact in a positive feedback loop with inflammatory mediators in keratinocytes. The pro-inflammatory cytokine tumor necrosis factor α (TNFα) was used to induce an inflammatory state in cultured keratinocytes. TNFα increased interleukin (IL)-1β, IL-6, IL-8 and nerve growth factor (NGF) production and gene expression levels of α₁-AR subtype B (α_1B-AR). Additional stimulation of α₁-AR further increased IL-6 levels, while maintaining high levels of IL-8 and decreasing levels of IL-1β and NGF. Our results suggest that reciprocal influences between α₁-ARs and inflammatory cytokines may play a role in normal inflammatory responses. However, if unchecked, this cycle could contribute to pathology (e.g. chronic inflammatory diseases, chronic pain conditions, and stress-induced cancer progression).

Joints for joints: cannabinoids in the treatment of rheumatoid arthritis

PURPOSE OF REVIEW

An increasing number of patients with rheumatoid arthritis (RA) are using cannabis to treat their symptoms, although systematic studies regarding efficacy in RA are lacking. Within this review we will give an overview on the overall effects of cannabinoids in inflammation and why they might be useful in the treatment of RA.

RECENT FINDINGS

Peripherally, cannabinoids show anti-inflammatory effects by activating cannabinoid type 2 receptors (CB2) which decrease cytokine production and immune cell mobilization. In contrast, cannabinoid type 1 receptor (CB1) activation on immune cells is proinflammatory while CB1 antagonism provides anti-inflammatory effects by increasing β2-adrenergic signaling in the joint and secondary lymphoid organs. In addition, the nonpsychotropic cannabinoid, cannabidiol (CBD) demonstrated antiarthritic effects independent of cannabinoid receptors. In addition to controlling inflammation, cannabinoids reduce pain by activating central and peripheral CB1, peripheral CB2 receptors and CBD-sensitive noncannabinoid receptor targets.

SUMMARY

Cannabinoids might be a suitable treatment for RA, but it is important to target the right receptors in the right place. For clinical studies, we propose a combination of a CB2 agonist to decrease cytokine production, a peripheral CB1 antagonist to prevent detrimental CB1 signaling and to support anti-inflammatory effects of CB2 via activation of β2-adrenergic receptors and CBD to induce cannabinoid-receptor-independent anti-inflammatory effects.

Life Events, Emotions, and Immune Function: Evidence from Whitehall II Cohort Study

Stressful life events have been shown to increase vulnerability to infections. However, the effects may be dependent on specific emotional responses associated with these events. In general, negative emotions are thought to exacerbate and positive emotions to protect from the adverse effects of stressors on health. In this study, we adopted an evolutionary and functionalist perspective on emotions and hypothesized that both positive and negative emotions in response to stressful events are protective, whereas absence of emotional reactions exacerbates vulnerability to infections. We assessed immune function using lymphocytes to white blood cells ratio as a proxy for current viral infection in 3,008 British civil workers (30% women). No main effect of stressful life events or emotions on lymphocyte ratio was observed in either sex. However, in men, there was an interaction of life events with both positive and negative emotions as well as a combined measure of general affect. Supporting our hypothesis, stressful life events were associated with impaired immune function in men who reported very low levels of both positive and negative emotions but not in others. We discuss potential benefits of negative and positive emotions in the context of stress and immunity.