The role of adrenal gland microenvironment in the HPA axis function and dysfunction during sepsis

Novel cortisol trajectory sub-phenotypes in sepsis

BACKGROUND

Sepsis is a heterogeneous syndrome. This study aimed to identify new sepsis sub-phenotypes using plasma cortisol trajectory.

METHODS

This retrospective study included patients with sepsis admitted to the intensive care unit of Zhongshan Hospital Fudan University between March 2020 and July 2022. A group-based cortisol trajectory model was used to classify septic patients into different sub-phenotypes. The clinical characteristics, biomarkers, and outcomes were compared between sub-phenotypes.

RESULTS

A total of 258 patients with sepsis were included, of whom 186 were male. Patients were divided into two trajectory groups: the lower-cortisol group (n = 217) exhibited consistently low and slowly declining cortisol levels, while the higher-cortisol group (n = 41) showed relatively higher levels in comparison. The 28-day mortality (65.9% vs.16.1%, P < 0.001) and 90-day mortality (65.9% vs. 19.8%, P < 0.001) of the higher-cortisol group were significantly higher than the lower-cortisol group. Multivariable Cox regression analysis showed that the trajectory sub-phenotype (HR = 5.292; 95% CI 2.218-12.626; P < 0.001), APACHE II (HR = 1.109; 95% CI 1.030-1.193; P = 0.006), SOFA (HR = 1.161; 95% CI 1.045-1.291; P = 0.006), and IL-1β (HR = 1.001; 95% CI 1.000-1.002; P = 0.007) were independent risk factors for 28-day mortality. Besides, the trajectory sub-phenotype (HR = 4.571; 95% CI 1.980-10.551; P < 0.001), APACHE II (HR = 1.108; 95% CI 1.043-1.177; P = 0.001), SOFA (HR = 1.270; 95% CI 1.130-1.428; P < 0.001), and IL-1β (HR = 1.001; 95% CI 1.000-1.001; P = 0.015) were also independent risk factors for 90-day mortality.

CONCLUSION

This study identified two novel cortisol trajectory sub-phenotypes in patients with sepsis. The trajectories were associated with mortality, providing new insights into sepsis classification.

Co-administration of xylo-oligosaccharides produced by immobilized Aspergillus terreus xylanase with carbimazole to mitigate its adverse effects on the adrenal gland

Carbimazole has disadvantages on different body organs, especially the thyroid gland and, rarely, the adrenal glands. Most studies have not suggested any solution or medication for ameliorating the noxious effects of drugs on the glands. Our study focused on the production of xylooligosaccharide (XOS), which, when coadministered with carbimazole, relieves the toxic effects of the drug on the adrenal glands. In addition to accelerating the regeneration of adrenal gland cells, XOS significantly decreases the oxidative stress caused by obesity. This XOS produced by Aspergillus terreus xylanase was covalently immobilized using microbial Scleroglucan gel beads, which improved the immobilization yield, efficiency, and operational stability. Over a wide pH range (6-7.5), the covalent immobilization of xylanase on scleroglucan increased xylanase activity compared to that of its free form. Additionally, the reaction temperature was increased to 65 °C. However, the immobilized enzyme demonstrated superior thermal stability, sustaining 80.22% of its original activity at 60 °C for 120 min. Additionally, the full activity of the immobilized enzyme was sustained after 12 consecutive cycles, and the activity reached 78.33% after 18 cycles. After 41 days of storage at 4 °C, the immobilized enzyme was still active at approximately 98%. The immobilized enzyme has the capability to produce xylo-oligosaccharides (XOSs). Subsequently, these XOSs can be coadministered alongside carbimazole to mitigate the adverse effects of the drug on the adrenal glands. In addition to accelerating the regeneration of adrenal gland cells, XOS significantly decreases the oxidative stress caused by obesity.

Mechanism and therapeutic potential of traditional Chinese medicine extracts in sepsis

Sepsis is a complex syndrome characterized by multi-organ dysfunction, due to the presence of harmful microorganisms in blood which could cause mortality. Complications associated with sepsis involve multiple organ dysfunction. The pathogenesis of sepsis remains intricate, with limited treatment options and high mortality rates. Traditional Chinese medicine (TCM) has consistently demonstrated to have a potential on various disease management. Its complements include reduction of oxidative stress, inhibiting inflammatory pathways, regulating immune responses, and improving microcirculation. Traditional Chinese medicine can mitigate or even treat sepsis in a human system. This review examines progress on the use of TCM extracts for treating sepsis through different pharmacological action and its mechanisms. The potential targets of TCM extracts and active ingredients for the treatment of sepsis and its complications have been elucidated through molecular biology research, network pharmacology prediction, molecular docking analysis, and visualization analysis. Our aim is to provide a theoretical basis and empirical support for utilizing TCM in the treatment of sepsis and its complications while also serving as a reference for future research and development of sepsis drugs.

Experimental Models of Hospital-Acquired Infections After Traumatic Brain Injury: Challenges and Opportunities

Patients hospitalized after a moderate or severe traumatic brain injury (TBI) are at increased risk of nosocomial infections, including bacterial pneumonia and other upper respiratory tract infections. Infections represent a secondary immune challenge for vulnerable TBI patients that can lead to increased morbidity and poorer long-term prognosis. This review first describes the clinical significance of infections after TBI, delving into the known mechanisms by which a TBI can alter systemic immunological responses towards an immunosuppressive state, leading to promotion of increased vulnerability to infections. Pulmonary dysfunction resulting from respiratory tract infections is considered in the context of neurotrauma, including the bidirectional relationship between the brain and lungs. Turning to pre-clinical modeling, current laboratory approaches to study experimental TBI and lung infections are reviewed, to highlight findings from the limited key studies to date that have incorporated both insults. Then, practical decisions for the experimental design of animal studies of post-injury infections are discussed. Variables associated with the host animal, the infectious agent (e.g., species, strain, dose, and administration route), as well as the timing of the infection relative to the injury model are important considerations for model development. Together, the purpose of this review is to highlight the significant clinical need for increased pre-clinical research into the two-hit insult of a hospital-acquired infection after TBI to encourage further scientific enquiry in the field.

Evidence of the Role of Inflammation and the Hormonal Environment in the Pathogenesis of Adrenal Myelolipomas in Congenital Adrenal Hyperplasia

Adrenal myelolipomas (AML) are composed of mature adipose and hematopoietic components. They represent approximately 3 percent of adrenal tumors and are commonly found in patients with congenital adrenal hyperplasia (CAH). CAH provides a unique environment to explore AML pathogenesis. We aimed to evaluate the role of the immune system and hormones that accumulate in poorly controlled CAH in the development of AML. When compared to normal adrenal tissue, CAH-affected adrenal tissue and myelolipomas showed an increased expression of inflammatory cells (CD68, IL2Rbeta), stem cells (CD117) B cells (IRF4), and adipogenic markers (aP2/FABP4, AdipoQ, PPARγ, Leptin, CideA), and immunostaining showed nodular lymphocytic accumulation. Immunohistochemistry staining revealed a higher density of inflammatory cells (CD20, CD3, CD68) in CAH compared to non-CAH myelolipomas. In vitro RNA-sequencing studies using NCI-H295R adrenocortical cells with exogenous exposure to ACTH, testosterone, and 17-hydroxyprogesterone hormones, showed the differential expression of genes involved in cell cycle progression, phosphorylation, and tumorigenesis. Migration of B-lymphocytes was initiated after the hormonal treatment of adrenocortical cells using the Boyden chamber chemotaxis assay, indicating a possible hormonal influence on triggering inflammation and the development of myelolipomas. These findings demonstrate the important role of inflammation and the hormonal milieu in the development of AML in CAH.

Aging of the adrenal gland and its impact on the stress response

This article discusses the physiological and anatomical changes of adrenal gland with age and the effects this has overall on how the organ responds to stress. Physiological changes entail a decrease in adrenocorticoid hormone secretion however cortisol levels remain intact leading to a disruptive stress response. Additionally, loss of zonation of the organ also occurs. Both characteristics in combination with chronic stress affect overall health. Complex interplay between adrenal aging and stress responsiveness is confounded further by the impact they expel on other systems, such as the thyroid hormone. The body undergoes age-related transformations modifying rate of cellular growth, differentiation, senescence, and hormone production. Given the multiplicity and complexity of hormones, their production must be considered to develop appropriate interventions to mitigate its effect on age related diseases in health.

The pathogenesis and potential therapeutic targets in sepsis

Sepsis is defined as "a life-threatening organ dysfunction caused by dysregulated host systemic inflammatory and immune response to infection." At present, sepsis continues to pose a grave healthcare concern worldwide. Despite the use of supportive measures in treating traditional sepsis, such as intravenous fluids, vasoactive substances, and oxygen plus antibiotics to eradicate harmful pathogens, there is an ongoing increase in both the morbidity and mortality associated with sepsis during clinical interventions. Therefore, it is urgent to design specific pharmacologic agents for the treatment of sepsis and convert them into a novel targeted treatment strategy. Herein, we provide an overview of the molecular mechanisms that may be involved in sepsis, such as the inflammatory response, immune dysfunction, complement deactivation, mitochondrial damage, and endoplasmic reticulum stress. Additionally, we highlight important targets involved in sepsis-related regulatory mechanisms, including GSDMD, HMGB1, STING, and SQSTM1, among others. We summarize the latest advancements in potential therapeutic drugs that specifically target these signaling pathways and paramount targets, covering both preclinical studies and clinical trials. In addition, this review provides a detailed description of the crosstalk and function between signaling pathways and vital targets, which provides more opportunities for the clinical development of new treatments for sepsis.

Unbiased multitissue transcriptomic analysis reveals complex neuroendocrine regulatory networks mediated by spinal cord injury-induced immunodeficiency

BACKGROUND

Spinal cord injury (SCI), which causes loss of sensory and motor function in the body below the level of injury, is a devastating disease of the central nervous system. SCI leads to severe secondary immunosuppression, called SCI-induced immunodeficiency syndrome (SCI-IDS), which is characterized by increased susceptibility to infection and further exacerbates neurological dysfunction. Several studies have suggested that SCI-IDS is an independent risk factor for poor neurological prognosis. SCI-IDS predominantly occurs following injury above the T5 levels and eventually leads to systemic immune failure, possibly via the sympathetic-adrenal medullary axis and the hypothalamic‒pituitary‒adrenal (HPA) axis. However, the mechanism remains unclear.

METHODS AND OBJECTIVES

The concentrations of adrenocorticotropic hormone and cortisol in plasma, as well as changes in sympathetic activity (blood pressure and catecholamine levels in plasma), were assessed in rats in the high-level (T3) spinal cord injury (T3-SCI) group and the low-level (T10) spinal cord injury (T10-SCI) group. Second, the differential regulation of the gene network between the sympathetic-adrenal medullary axis and the HPA axis was explored by histology and multitissue transcriptomics, and the neuroendocrine-immune network associated with SCI-IDS was further elucidated.

RESULTS

The spleen and thymus gland, which are secondary immune organs, were significantly atrophied in rats in the T3-SCI group, and the white pulp of the spleen was significantly atrophied. The level of cortisol, which is mediated by the adrenal glands, was markedly elevated, but norepinephrine levels were markedly decreased. There was no difference in adrenocorticotropic hormone expression between any of the groups. The transcriptome analysis results showed that the downregulated differentially expressed genes (DEGs) in the T3-SCI group were enriched in the GO term immunoregulation, indicating that splenic immune function was markedly impaired after high-level SCI. The upregulated DEGs in the hypothalamus (hub genes: Nod2, Serpine1, Cebpb, Nfkbil1, Ripk2, Zfp36, Traf6, Akap8, Gfer, Cxcl10, Tnfaip3, Icam1, Fcgr2b, Ager, Dusp10, and Mapkapk2) were significantly enriched in inflammatory pathways, and the downregulated genes (hub genes: Grm4, Nmu, P2ry12, rt1-bb1, Oprm1, Zfhx2, Gpr83, and Chrm2) were enriched in pathways related to inhibitory Gi-mediated G protein-coupled receptor (Gi-GPCR) neurons and neuropeptide changes. The upregulated genes in the adrenal glands (hub genes: Ciart, per2, per3, cry1, and cry2) were enriched in cortisol secretion and circadian rhythm changes, and the downregulated genes (hub genes: IL7r, rt1-bb, rt1-bb1, rt1-da, rt1-ba, cd74, cxcr3, vcam1, ccl5, bin1, and IL8) were significantly enriched in MHC-mediated immune responses.

CONCLUSIONS

To explore the possible mechanism underlying SCI-IDS, this study assessed the differential regulation of the gene network associated with neuroendocrine immunity after SCI. Progressive neuroinflammation spreads after injury, and neurotransmission through Gi-mediated G protein-coupled receptors in the HPA axis and neuropeptide production by the hypothalamus are inhibited. Disruption of the connection between the hypothalamus and the adrenal glands causes autonomous regulation of the adrenal glands, disturbance of circadian rhythm and finally hypercortisolemia, leading to general suppression of peripheral adaptive immunity. Neuraxial nerve inflammation caused by SCI persists indefinitely, blocking nerve repair; persistent system-wide immunosuppression in the periphery results in increased susceptibility to infection, leading to poor neurological prognosis.

Sex, sepsis and the brain: defining the role of sexual dimorphism on neurocognitive outcomes after infection

Sexual dimorphisms exist in multiple domains, from learning and memory to neurocognitive disease, and even in the immune system. Male sex has been associated with increased susceptibility to infection, as well as increased risk of adverse outcomes. Sepsis remains a major source of morbidity and mortality globally, and over half of septic patients admitted to intensive care are believed to suffer some degree of sepsis-associated encephalopathy (SAE). In the short term, SAE is associated with an increased risk of in-hospital mortality, and in the long term, has the potential for significant impairment of cognition, memory, and acceleration of neurocognitive disease. Despite increasing information regarding sexual dimorphism in neurologic and immunologic systems, research into these dimorphisms in sepsis-associated encephalopathy remains critically understudied. In this narrative review, we discuss how sex has been associated with brain morphology, chemistry, and disease, sexual dimorphism in immunity, and existing research into the effects of sex on SAE.

Transcriptome Profile of the Rat Adrenal Gland: Parenchymal and Interstitial Cells

The homeostasis of the adrenal gland plays a decisive role in its proper functioning, both in non-stressful conditions and under the influence of various types of stress. This consists of interactions between all types of cells that make up the organ, including parenchymal and interstitial cells. The amount of available information on this subject in the rat adrenal glands under non-stressful conditions is insufficient; the aim of the research was to determine the expression of marker genes for rat adrenal cells depending on their location. The material for the study consisted of adrenal glands taken from intact adult male rats that were separated into appropriate zones. Transcriptome analysis by means of Affymetrix^® Rat Gene 2.1 ST Array was used in the study, followed by real-time PCR validation. Expression analysis of interstitial cell marker genes revealed both the amount of expression of these genes and the zone in which they were expressed. The expression of marker genes for fibroblasts was particularly high in the cells of the ZG zone, while the highest expression of specific macrophage genes was observed in the adrenal medulla. The results of this study, especially with regard to interstitial cells, provide a so far undescribed model of marker gene expression of various cells, both in the cortex and medulla of the sexually mature rat adrenal gland. The interdependence between parenchymal and interstitial cells creates a specific microenvironment that is highly heterogeneous within the gland with respect to some of the interstitial cells. This phenomenon most likely depends on the interaction with the differentiated parenchymal cells of the cortex, as well as the medulla of the gland.

Altered glucose-dependent secretion of glucagon and ACTH is associated with insulin resistance, assessed by population analysis

This study aimed to characterize how the dysregulation of counter-regulatory hormones can contribute to insulin resistance and potentially to diabetes. Therefore, we investigated the association between insulin sensitivity and the glucose- and insulin-dependent secretion of glucagon, adrenocorticotropic hormone (ACTH), and cortisol in non-diabetic individuals using a population model analysis. Data, from hyperinsulinemic-hypoglycemic clamps, were pooled for analysis, including 52 individuals with a wide range of insulin resistance (reflected by glucose infusion rate 20-60 min; GIR20-60min). Glucagon secretion was suppressed by glucose and, to a lesser extent, insulin. The GIR20-60min and BMI were identified as predictors of the insulin effect on glucagon. At normoglycemia (5 mmol/L), a 90% suppression of glucagon was achieved at insulin concentrations of 16.3 and 43.4 µU/mL in individuals belonging to the highest and lowest quantiles of insulin sensitivity, respectively. Insulin resistance of glucagon secretion explained the elevated fasting glucagon for individuals with a low GIR20-60min. ACTH secretion was suppressed by glucose and not affected by insulin. The GIR20-60min was superior to other measures as a predictor of glucose-dependent ACTH secretion, with 90% suppression of ACTH secretion by glucose at 3.1 and 3.5 mmol/L for insulin-sensitive and insulin-resistant individuals, respectively. This difference may appear small but shifts the suppression range into normoglycemia for individuals with insulin resistance, thus, leading to earlier and greater ACTH/cortisol response when the glucose falls. Based on modeling of pooled glucose-clamp data, insulin resistance was associated with generally elevated glucagon and a potentiated cortisol-axis response to hypoglycemia, and over time both hormonal pathways may therefore contribute to dysglycemia and possibly type 2 diabetes.

Adrenal heterogeneity in the arterial phase of contrast-enhanced CT predicts prognosis in septic shock: comparison with hollow adrenal gland sign

PURPOSE

To evaluate the prognostic value of adrenal heterogeneity in the arterial phase in patients with septic shock, comparatively to the hollow adrenal gland sign (HAGS).

METHODS

Totally 84 consecutive patients with septic shock (group S) were assessed retrospectively, and abdominal dual-phase contrast-enhanced CT was performed after the diagnosis of septic shock within one week. The patients were divided into two groups according to clinical outcome, including the survivor (group A, 41 cases) and death (group B, 43 cases) groups. Fifty negative cases were matched as the control (group C). The incidence of the HAGS in patients with septic shock (group S) was statistically analyzed. The average values of left adrenal density (Den-A and Den-V) and their standard deviations (SD_Den-A and SD_Den-V) in dual phases were measured. The above parameters were compared between groups A and B as well as with group C. The parameters were assessed for their predictive values of mortality in septic shock, comparatively to the HAGS.

RESULTS

Compared with group C, group S presented significantly higher Den-A (P = 0.003) and SD_Den-A (P < 0.001). There were significantly higher SD_Den-A (P < 0.001) in group B compared with group A. The incidence of the HAGS was about 27.4% (23/84) in group S. The sensitivity and specificity in predicting poor prognosis in patients with septic shock were 78% and 85% with SD_Den-A, at a cut-off value of 28.64, respectively. The sensitivity and specificity were 41% and 88% for the HAGS, respectively. The area under ROC curve (AUC) was significantly greater for SD_Den-A compared with the HAGS (0.820 vs. 0.670, P < 0.001).

CONCLUSION

Adrenal heterogeneity in the arterial phase can predict prognosis in patients with septic shock; the larger the SD_Den-A, the poorer the prognosis. The predictive efficiency of adrenal heterogeneity in the arterial phase is better than the HAGS.

Single-cell atlas of murine adrenal glands reveals immune-adrenal crosstalk during systemic <i>Candida albicans</i> infection

Fungal sepsis remains a major health threat with high mortality, where the adrenal gland stress response has been rarely reported. <i>Candida albicans</i> (<i>C.albicans</i>) is the most common opportunistic fungal pathogen of life-threatening disseminated candidiasis and fungal sepsis. In the present study, we performed single-cell RNA sequencing (scRNA-Seq) using the 10x Genomics platform to analyze the changes in murine adrenal transcriptome following systemic <i>C.albicans</i> infection. A total of 16 021 cells were categorized into 18 transcriptionally distinct clusters, representing adrenocortical cells, endothelial cells, various immune cells, mesenchymal cells, smooth muscle cells, adrenal capsule, chromaffin cells, neurons and glials. As the main cell component in the adrenal gland responsible for steroidogenesis, the adrenocortical cells dramatically diminished and were further grouped into 10 subclusters, which differently distributed in the infected and uninfected samples. Pseudo-time analysis revealed transitions of the adrenocortical cells from the initial normal states to active or dysfunctional states following systemic <i>C.albicans</i> infection <i>via</i> two trajectory paths. Endothelial cells in the highly vascularized organ of adrenal gland further proliferated following infection, with the upregulation of genes positively regulating angiogenesis and downregulation of protective genes of endothelial cells. Immune cells were also excessively infiltrated in adrenal glands of <i>C.albicans</i>-infected mice. Macrophages dominated the immune microenvironments in murine adrenal glands both before and after <i>C.albicans</i> infection, mediating the crosstalk among the steroid-producing cells, endothelial cells and immune cells within the adrenal gland. NLR family, pyrin domain containing 3 (NLRP3, encoded by <i>Nlrp3</i>) and complement receptor 3 (CR3, encoded by <i>Itgam</i>) were found to be significantly upregulated on the adrenal macrophages upon systemic <i>C.albicans</i> infection and might play critical roles in mediating the myeloid response. Meanwhile, the number and strength of the interactions between the infiltrating immune cells and adrenal resident cells were unveiled by cell-cell communication analysis to be dramatically increased after systemic <i>C.albicans</i> infection, indicating that the immune-adrenal crosstalk might contribute to the compromised functions of adrenal cells. Overall, our comprehensive picture of the murine adrenal gland microenvironment in systemic <i>C.albicans</i> infection provides deeper insights into the immune-adrenal cell communications during fungal sepsis.

Neuroimmune Regulation in Sepsis-Associated Encephalopathy: The Interaction Between the Brain and Peripheral Immunity

Sepsis-associated encephalopathy (SAE), the most popular cause of coma in the intensive care unit (ICU), is the diffuse cerebral damage caused by the septic challenge. SAE is closely related to high mortality and extended cognitive impairment in patients in septic shock. At present, many studies have demonstrated that SAE might be mainly associated with blood–brain barrier damage, abnormal neurotransmitter secretion, oxidative stress, and neuroimmune dysfunction. Nevertheless, the precise mechanism which initiates SAE and contributes to the long-term cognitive impairment remains largely unknown. Recently, a growing body of evidence has indicated that there is close crosstalk between SAE and peripheral immunity. The excessive migration of peripheral immune cells to the brain, the activation of glia, and resulting dysfunction of the central immune system are the main causes of septic nerve damage. This study reviews the update on the pathogenesis of septic encephalopathy, focusing on the over-activation of immune cells in the central nervous system (CNS) and the “neurocentral–endocrine–immune” networks in the development of SAE, aiming to further understand the potential mechanism of SAE and provide new targets for diagnosis and management of septic complications.

Sufentanil Alleviates Sepsis-Induced Myocardial Injury and Stress Response in Rats through the ERK/GSK-3β Signaling Axis

Objective

To explore the effect and possible mechanism of sufentanil on sepsis-induced myocardial injury and stress response in rats.

Methods

The cecal ligation and puncture (CLP) method was utilized to establish the sepsis model of rats to explore the effect of sufentanil pretreatment with different concentrations on myocardial injury and oxidative stress in CLP rats. Echocardiogram was applied for detecting cardiac hemodynamic parameters in rats; hematoxylin and eosin (HE) staining as well as TUNEL staining was done for observing pathological changes of myocardial tissue and cardiomyocyte apoptosis in rats, respectively; biochemical testing and enzyme-linked immunosorbent assay (ELISA) were done for determining myocardial injury marker level in serum, oxidative stress substances in myocardial tissue, and neuroendocrine hormone level in serum of rats, respectively; finally, Western blot was performed for checking the expression level of ERK/GSK-3β signaling pathway-related proteins in myocardial tissue of rats.

Results

A model of rat with sepsis-induced myocardial injury was constructed with the CLP method. Specifically, this rat model was characterized by obvious cardiac function and tissue damage, cardiomyocyte apoptosis, and oxidative stress response. Sufentanil pretreatment significantly improved cardiac function injury, alleviated pathological injury and oxidative stress response in myocardial tissue, and inhibited cardiomyocyte apoptosis. Specifically, after sufentanil pretreatment, left ventricular end-diastolic dimension (LVEDD) and left ventricular end-systolic dimension (LVESD) were downregulated, and left ventricular ejection fraction (LVEF) was upregulated; the level of B-type natriuretic peptide (BNP) of serum, creatine kinase isoenzyme (CK-MB), and troponin (cTnl) decreased; besides, malondialdehyde (MDA) level was declined, while activities of superoxide dismutase (SOD) and catalase (CAT) were increased. What is more, further mechanism exploration also revealed that sufentanil could reverse the activity of the sepsis-induced ERK/GSK-3β signaling pathway.

Conclusion

Sufentanil has an obvious protective effect on myocardial injury and stress response in CLP rats, and this protective effect may be related to the activation of the ERK/GSK-3β signaling pathway.

Targeting HMGB1 for the treatment of sepsis and sepsis-induced organ injury

High mobility group box 1 (HMGB1) is a ubiquitous nuclear protein that is present in almost all cells and regulates the activity of innate immune responses in both intracellular and extracellular settings. Current evidence suggests that HMGB1 plays a pivotal role in human pathological and pathophysiological processes such as the inflammatory response, immune reactions, cell migration, aging, and cell death. Sepsis is a systemic inflammatory response syndrome (SIRS) that occurs in hosts in response to microbial infections with a proven or suspected infectious etiology and is the leading cause of death in intensive care units worldwide, particularly in the aging population. Dysregulated systemic inflammation is a classic characteristic of sepsis, and suppression of HMGB1 may ameliorate inflammation and improve patient outcomes. Here, we focus on the latest breakthroughs regarding the roles of HMGB1 in sepsis and sepsis-related organ injury, the ways by which HMGB1 are released, and the signaling pathways and therapeutics associated with HMGB1. This review highlights recent advances related to HMGB1: the regulation of HMBG1 might be helpful for both basic research and drug development for the treatment of sepsis and sepsis-related organ injury.

Tumors Modulate the Systemic Vascular Response to Anti‐angiogenic Therapy

Toxicologic evaluation of new drug candidates routinely utilizes healthy animals. In oncology, there remains a limited understanding of the effects of novel test candidates in a diseased host. For vascular modulating agents (VMAs), an increased understanding of preclinical tumour–host interaction, and its potential to exacerbate or alleviate ‘off‐target’ effects of anti‐angiogenic administration, could aid in the prediction of adverse clinical outcomes in a defined cancer patient. We have previously reported that the implantation and growth of a range of human‐ and mouse‐derived tumours leads to structural vascular and, potentially, functional signalling changes within host mouse endocrine tissues, indicating possible roles for tumour‐ and host‐derived cytokines/growth factors and the liberation of myeloid‐derived suppressor cells in this phenomenon. Here, we further demonstrate that the growth of the Calu‐6 xenograft is associated with a resistance to VMA‐induced mouse peripheral endocrine vascular rarefaction (toxicity), with potential functional impact, notably with respect to mixed tyrosine kinase inhibition. The pathogenesis of these findings indicates a potential role for both tumour‐ and host‐derived basic fibroblast growth factor (bFGF), with associated upregulation in the intra‐tumoural autotaxin‐lysophosphatic acid signalling axis.

The growth of the Calu‐6 xenograft is associated with a resistance to vascular modulating agent‐induced mouse peripheral endocrine vascular rarefaction (toxicity), with potential functional impact, notably with respect to mixed tyrosine kinase inhibition. The pathogenesis of these findings indicates a potential role for basic fibroblast growth factor, with associated upregulation in the autotaxin‐lysophosphatic acid signalling axis.

Restrained expression of canine glucocorticoid receptor splice variants α and P prognosticates fatal disease outcome in SIRS

Glucocorticoids play a central role in the inflammatory response and alleviate the symptoms in critically ill patients. The glucocorticoid action relies on the glucocorticoid receptor (GR) which translocates into the nucleus upon ligand-binding and regulates transcription of a battery of genes. Although the GR is encoded by a single gene, dozens of its splice variants have been described in diverse species. The GRα isoform encodes the full, functionally active protein that is composed of a transactivation, a DNA-binding, and a C-terminal ligand-binding domain. The second most highly expressed receptor variant, the GR-P, is formed by an intron retention that introduces an early stop codon and results in a probably dysfunctional protein with truncated ligand-binding domain. We described the canine ortholog of GR-P and showed that this splice variant is highly abundant in the peripheral blood of dogs. The level of cGRα and cGR-P transcripts are elevated in patients of SIRS and the survival rate is increased with elevated cGRα and cGR-P expression. The ratio of cGRα and cGR-P mRNA did not differ between the survivor and non-survivor patients; thus, the total GR expression is more pertinent than the relative expression of GR isoforms in assessment of the disease outcome.

UPLC-Q-TOF/MS-Based Plasma and Urine Metabolomics Contribute to the Diagnosis of Sepsis

In this study, we aimed to identify potential metabolic biomarkers that can improve the diagnostic accuracy of sepsis. Sixty-six patients including 30 septic and 36 nonsepsis patients from an intensive care unit were recruited. The global plasma and urine metabolomic profiles were determined by ultraperformance liquid chromatography coupled with a quadrupole time-of-flight mass spectrometry-based methodology. The risk factors, including both traditional physiological indicators and metabolic biomarkers, were investigated by binary logistic regression analysis and used to build a least absolute shrinkage and selection operator (Lasso) regression model to evaluate the ability of diagnosis. Fifty-five metabolites in plasma and 11 metabolites in urine were identified through orthogonal projections to latent structures discriminant analysis (OPLS-DA). Among them, ten (PE (20:4(5Z, 8Z, 11Z, 14Z)/P-18:0), harderoporphyrinogen, chloropanaxydiol, (Z)-2-octenal, N¹,N⁸-diacetylspermidine, 1-nitroheptane, venoterpine, α-CEHC, LysoPE (20:0/0:0), corticrocin) metabolites were identified as risk factors. The Lasso regression model incorporating these ten metabolic biomarkers and five traditional physiological indicators displayed better differentiation than the traditional model, represented by the elevated area under receiver operating characteristic curve (AUROC) from 96.80 to 100.0%. Furthermore, patients with septic shock presented a significantly lower level of PE-Cer (d16:1(4E)/19:0). This study suggests that metabolomic profiling could be an effective tool for sepsis diagnosis.

Ambient fine particulate matter exposure disrupts circadian rhythm and oscillation of the HPA axis in a mouse model

Emerging evidence supports that exposure to ambient fine particulate matter (PM_2.5) is associated with the metabolic syndrome. As the main neuroendocrine axis in mammals, the hypothalamic-pituitary-adrenal (HPA) axis's circadian rhythm (CR) plays an essential role in regulating metabolic homeostasis. Our previous studies found that ambient PM_2.5 exposure caused CR disorder of the critical enzymes involved in lipid metabolism in mouse liver and adipose tissues. However, the impact of ambient PM_2.5 exposure on the HPA axis is not fully illustrated yet. Male C57BL/6 mice were randomly exposed to ambient PM_2.5 or filtered air for ten weeks via a whole-body exposure system. Rhythmic oscillations of clock genes in the hypothalamus and adrenal gland were characterized. The effects of ambient PM_2.5 exposure on clock gene expression and rhythmic expression of molecules related to glucocorticoid synthesis were also examined. Firstly, a more robust CR of clock genes was demonstrated in the adrenal gland than that in the hypothalamus. Secondly, PM_2.5 exposure significantly inhibited the expression of Clock at ZT8 in the hypothalamus. However, both circadian oscillation and expression levels of Bmal1, Cry1, Cry2, and Rorα were increased significantly by ambient PM_2.5 exposure in the adrenal gland. Moreover, abnormal rhythmic oscillation patterns of corticotropin-releasing hormone and adrenocorticotropic hormone were observed after ambient PM_2.5 exposure, with no change at the expression levels. Finally, the expression of Cyp11b1 was markedly decreased at ZT0 in the adrenal gland of PM_2.5 exposed mice. Our findings provide new insights into the ambient PM_2.5 exposure-induced metabolic syndrome from the perspective of CR disturbances.

Sepsis as a Pan-Endocrine Illness-Endocrine Disorders in Septic Patients

Sepsis is defined as "life-threatening organ dysfunction caused by a dysregulated host response to infection". One of the elements of dysregulated host response is an endocrine system disorder. Changes in its functioning in the course of sepsis affect almost all hormonal axes. In sepsis, a function disturbance of the hypothalamic-pituitary-adrenal axis has been described, in the range of which the most important seems to be hypercortisolemia in the acute phase. Imbalance in the hypothalamic-pituitary-thyroid axis is also described. The most typical manifestation is a triiodothyronine concentration decrease and reverse triiodothyronine concentration increase. In the somatotropic axis, a change in the secretion pattern of growth hormone and peripheral resistance to this hormone has been described. In the hypothalamic-pituitary-gonadal axis, the reduction in testosterone concentration in men and the stress-induced "hypothalamic amenorrhea" in women have been described. Catecholamine and β-adrenergic stimulation disorders have also been reported. Disorders in the endocrine system are part of the "dysregulated host response to infection". They may also affect other components of this dysregulated response, such as metabolism. Hormonal changes occurring in the course of sepsis require further research, not only in order to explore their potential significance in therapy, but also due to their promising prognostic value.

Tumors modulate fenestrated vascular beds and host endocrine status

Allograft and xenograft transplantation into a mouse host is frequently utilized to study cancer biology, tumor behavior, and response to treatment. Preclinical studies employing these models often focus solely upon the intra-tumoral effects of a given treatment, without consideration of systemic toxicity or tumor-host interaction, nor whether this latter relationship could modulate the toxicologic response to therapy. Here it is demonstrated that the implantation and growth of a range of human- and mouse-derived cell lines leads to structural vascular and, potentially, functional changes within peripheral endocrine tissues, a process that could conceivably ameliorate the severity of anti-angiogenic-induced fenestrated vessel attenuation. Observations suggest a multifactorial process, which may involve host- and tumor-derived cytokines/growth factors, and the liberation of myeloid-derived suppressor cells. Further investigation revealed a structurally comparable response to the administration of exogenous estrogen. These findings, in addition to providing insight into the development of clinical anti-angiogenic "adaptation," may be of significance within the "cancer-cachexia" and cancer-related anemia syndromes in man.

Single-cell transcriptomes reveal characteristic features of cell types within the human adrenal microenvironment

Various cells within the adrenal microenvironment are important in maintaining the body homeostasis. However, our understanding of adrenal disease pathogenesis is limited by an incomplete molecular characterization of the cell types responsible for the organ's multiple homeostatic functions. We report a cellular landscape of the human adrenal gland using single-cell RNA sequencing. We reveal characteristic features of cell types within the human adrenal microenvironment and found immune activation of nonimmune cells in the adrenal endothelial cells. We also reveal that abundant immune cells occupied a lot of space in adrenal gland. Additionally, Sex-related diversity in the adrenocortical cells and different gene expression profiles between the left and right adrenal gland are also observed at single-cell resolution. Together, at single-cell resolution, the transcriptomic map presents a comprehensive view of the human adrenal gland, which serves as a fundamental baseline description of this organ and paves a way for the further studies of adrenal diseases.

Triggering receptor expressed on myeloid Cells-2 (TREM2) inhibits steroidogenesis in adrenocortical cell by macrophage-derived exosomes in lipopolysaccharide-induced septic shock

PURPOSE

Endogenously produced glucocorticoids exhibit immunomodulating properties and are of pivotal importance for sepsis outcome. Uncontrolled activation of the immune-adrenal crosstalk increases the risk of sepsis-related death. Triggering receptor expressed on myeloid cells-2 (TREM2) is richly expressed on macrophages and has been demonstrated to improve outcome of sepsis by enhancing elimination of pathogens. However, the role and mode of action of macrophage TREM2 on adrenocortical steroidogenesis remains unclear in septic shock.

METHODS

The acute septic shock model was established by intraperitoneally challenging wild-type (WT) and TREM2 knock-out (Trem2-/-) mice with lipopolysaccharide (LPS, 30 mg/kg). The mice were assessed for TREM2 expression and local inflammation in adrenal gland and for synthesis of corticotropin releasing hormone (CRH) and adrenocorticotropic hormone (ACTH) in vivo. Bone marrow-derived macrophages or macrophage-derived exosomes were isolated from WT and Trem2-/- mice and were co-cultured with adrenocortical cells. The expression of steroidogenic enzymes and corticosterone production was assessed.

RESULTS

Genetic deficiency of TREM2 caused significantly higher corticosterone levels at the early stage of LPS-induced septic shock; whereas TREM2 deficiency neither increased CRH and ACTH nor exacerbated the inflammation in adrenocortical tissue during septic shock. Ex vivo study revealed that Trem2-/- macrophages significantly promoted the expression of steroidogenic enzymes and increased production of corticosterone. Furthermore, Trem2-/- macrophage-derived exosomes were able to mimic Trem2-/- macrophages in enhancing adrenocortical steroidogenesis.

CONCLUSIONS

At the early stage of LPS-induced septic shock, corticosterone biosynthesis can be inhibited by macrophage TREM2 in adrenocortical cells, which might partially associate with macrophage-derived exosomes.

A randomized cross-over trial assessing salivary and urinary cortisol concentrations after alfaxalone and propofol administration in healthy cats

The aim of this study was to assess the effects of commonly used anaesthetics alfaxalone and propofol on salivary and urinary cortisol in healthy cats. Fifteen male castrated research-purposed cats received randomly intravenous continuous rate infusions of 8 mg/kg/h of alfaxalone, 12 mg/kg/h of propofol and 2 ml/kg/h of Lactated Ringer's solution for 30 min, with intervals of 6 days between treatments. Saliva samples were collected for 24 h before each infusion and for 24 h from the start of each infusion. Urine was collected as single pooled samples over each 24 h period. Mean integrated saliva cortisol responses in cats treated with alfaxalone were greater than responses of cats treated with propofol (P = 0.034) and controls (P = 0.017). Integrated responses in cats treated with propofol did not differ from controls. The mean urinary cortisol/creatinine ratio (UCCR) was higher on the day of treatment than the day before treatment in cats treated with alfaxalone (P < 0.0001) and in cats treated with propofol (P = 0.0168) and did not differ between days in cats treated with lactated Ringer's solution. The mean UCCR was higher in cats treated with alfaxalone than in cats treated with lactated Ringer's solution (P = 0.0020) on the day of treatment. Mean total urinary cortisol over 24 h was greater in cats treated with alfaxalone than controls (P = 0.0267). In conclusion, alfaxalone increased short-term salivary and urinary cortisol concentrations in healthy cats as compared to propofol and a control group of non-anesthetised cats.

Sepsis-associated encephalopathy and septic encephalitis: an update

INTRODUCTION

Sepsis-associated encephalopathy (SAE) and septic encephalitis (SE) are associated with increased mortality, long-term cognitive impairment, and focal neurological deficits.

AREAS COVERED

The PUBMED database was searched 2016-2020. The clinical manifestation of SAE is delirium, SE additionally is characterized by focal neurological symptoms. SAE is caused by inflammation with endothelial/microglial activation, increase of permeability of the blood-brain-barrier, hypoxia, imbalance of neurotransmitters, glial activation, axonal, and neuronal loss. Septic-embolic (SEE) and septic-metastatic encephalitis (SME) are characterized by focal ischemia (SEE) and small abscesses (SME). The continuum between SAE, SME, and SEE is documented by imaging techniques and autopsies. The backbone of treatment is rapid optimum antibiotic therapy. Experimental approaches focus on modulation of inflammation, stabilization of the blood-brain barrier, and restoration of membrane/mitochondrial function.

EXPERT OPINION

The most promising diagnostic approaches are new imaging techniques. The most important measure to fight delirium remains establishment of daily structure and adequate sensory stimuli. Dexmedetomidine and melatonin appear to reduce the frequency of delirium, their efficacy in SAE and SE remains to be established. Drugs already licensed for other indications or available as food supplements which may be effective in SAE are statins, L-DOPA/benserazide, β-hydroxybutyrate, palmitoylethanolamide, and tetracyclines or other bactericidal non-lytic antibiotics.

Prolonged treatment with the synthetic glucocorticoid methylprednisolone affects adrenal steroidogenic function and response to inflammatory stress in the rat

Synthetic glucocorticoids are widely prescribed for the treatment of numerous inflammatory and autoimmune diseases and they can also affect the way the adrenal gland produces endogenous glucocorticoids. Indeed, patients undergoing synthetic glucocorticoid treatment can develop adrenal insufficiency, a condition characterised by reduced responsiveness of the adrenal to ACTH stimulation or stressors (e.g. surgical or inflammatory stress). To better elucidate the long-term effect of synthetic glucocorticoids treatment and withdrawal on adrenal function, we have investigated the long-term effects of prolonged treatment with methylprednisolone on HPA axis dynamics and on the adrenal steroidogenic pathway, both in basal conditions and in response to an inflammatory stress (lipopolysaccharide, LPS). We have found that 5-days treatment with methylprednisolone suppresses basal ACTH and corticosterone secretion, as well as corticosterone secretion in response to a high dose of ACTH, and down-regulates key genes in the adrenal steroidogenic pathway, including StAR, MRAP, CYP11a1 and CYP11b1. These effects were paralleled by changes in the adrenal expression of transcription factors regulating steroidogenic gene expression, as well as changes in the expression of adrenal clock genes. Importantly, 5 days after withdrawal of the treatment, ACTH levels are restored, yet basal levels of corticosterone, as well as most of the key steroidogenic genes and their regulators, remain down regulated. We also show that, although 5-days treatment with methylprednisolone reduces the corticosterone response to LPS, an increase in intra-adrenal pro-inflammatory cytokine gene expression was observed. Our data suggests that the steroidogenic pathway is directly affected by synthetic glucocorticoid treatment in the long-term, presumably via a mechanism involving activation of the glucocorticoid receptor. Furthermore, our data suggests a pro-inflammatory effect of synthetic glucocorticoids treatment in the adrenal gland.

Bidirectional Brain-gut-microbiota Axis in increased intestinal permeability induced by central nervous system injury

Central nervous system injuries may lead to the disorders of the hypothalamic‐pituitary‐adrenal axis, autonomic nervous system, and enteric nervous system. These effects then cause the changes in the intestinal microenvironment, such as a disordered intestinal immune system as well as alterations of intestinal bacteria. Ultimately, this leads to an increase in intestinal permeability. Inflammatory factors produced by the interactions between intestinal neurons and immune cells as well as the secretions and metabolites of intestinal flora can then migrate through the intestinal barrier, which will aggravate any peripheral inflammation and the central nervous system injury. The brain‐gut‐microbiota axis is a complex system that plays a crucial role in the occurrence and development of central nervous system diseases. It may also increase the consequences of preventative treatment. In this context, here we have summarized the factors that can lead to the increased intestinal permeability and some of the possible outcomes.

General Adaptation in Critical Illness: Glucocorticoid Receptor-alpha Master Regulator of Homeostatic Corrections

In critical illness, homeostatic corrections representing the culmination of hundreds of millions of years of evolution, are modulated by the activated glucocorticoid receptor alpha (GRα) and are associated with an enormous bioenergetic and metabolic cost. Appreciation of how homeostatic corrections work and how they evolved provides a conceptual framework to understand the complex pathobiology of critical illness. Emerging literature place the activated GRα at the center of all phases of disease development and resolution, including activation and re-enforcement of innate immunity, downregulation of pro-inflammatory transcription factors, and restoration of anatomy and function. By the time critically ill patients necessitate vital organ support for survival, they have reached near exhaustion or exhaustion of neuroendocrine homeostatic compensation, cell bio-energetic and adaptation functions, and reserves of vital micronutrients. We review how critical illness-related corticosteroid insufficiency, mitochondrial dysfunction/damage, and hypovitaminosis collectively interact to accelerate an anti-homeostatic active process of natural selection. Importantly, the allostatic overload imposed by these homeostatic corrections impacts negatively on both acute and long-term morbidity and mortality. Since the bioenergetic and metabolic reserves to support homeostatic corrections are time-limited, early interventions should be directed at increasing GRα and mitochondria number and function. Present understanding of the activated GC-GRα's role in immunomodulation and disease resolution should be taken into account when re-evaluating how to administer glucocorticoid treatment and co-interventions to improve cellular responsiveness. The activated GRα interdependence with functional mitochondria and three vitamin reserves (B1, C, and D) provides a rationale for co-interventions that include prolonged glucocorticoid treatment in association with rapid correction of hypovitaminosis.

Expression of α3β2β4 nicotinic acetylcholine receptors by rat adrenal chromaffin cells determined using novel conopeptide antagonists

Adrenal chromaffin cells release neurotransmitters in response to stress and may be involved in conditions such as post-traumatic stress and anxiety disorders. Neurotransmitter release is triggered, in part, by activation of nicotinic acetylcholine receptors (nAChRs). However, despite decades of use as a model system for studying exocytosis, the nAChR subtypes involved have not been pharmacologically identified. Quantitative real-time PCR of rat adrenal medulla revealed an abundance of mRNAs for α3, α7, β2, and β4 subunits. Whole-cell patch-clamp electrophysiology of chromaffin cells and subtype-selective ligands were used to probe for nAChRs derived from the mRNAs found in adrenal medulla. A novel conopeptide antagonist, PeIA-5469, was created that is highly selective for α3β2 over other nAChR subtypes heterologously expressed in Xenopus laevis oocytes. Experiments using PeIA-5469 and the α3β4-selective α-conotoxin TxID revealed that rat adrenal medulla contain two populations of chromaffin cells that express either α3β4 nAChRs alone or α3β4 together with the α3β2β4 subtype. Conclusions were derived from observations that acetylcholine-gated currents in some cells were sensitive to inhibition by PeIA-5469 and TxID, while in other cells, currents were sensitive only to TxID. Expression of functional α7 nAChRs was determined using three α7-selective ligands: the agonist PNU282987, the positive allosteric modulator PNU120596, and the antagonist α-conotoxin [V11L,V16D]ArIB. The results of these studies identify for the first time the expression of α3β2β4 nAChRs as well as functional α7 nAChRs by rat adrenal chromaffin cells.

New insights into pediatric community-acquired pneumonia gained from untargeted metabolomics: A preliminary study

BACKGROUND

Available diagnostics often fail to distinguish viral from bacterial causes of pediatric community-acquired pneumonia (pCAP). Metabolomics, which aims at characterizing diseases based on their metabolic signatures, has been applied to expand pathophysiological understanding of many diseases. In this exploratory study, we used the untargeted metabolomic analysis to shed new light on the etiology of pCAP.

METHODS

Liquid chromatography coupled with mass spectrometry was used to quantify the metabolite content of urine samples collected from children hospitalized for CAP of pneumococcal or viral etiology, ascertained using a conservative algorithm combining microbiological and biochemical data.

RESULTS

Fifty-nine children with CAP were enrolled over 16 months. Pneumococcal and viral cases were distinguished by means of a multivariate model based on 93 metabolites, 20 of which were identified and considered as putative biomarkers. Among these, six metabolites belonged to the adrenal steroid synthesis and degradation pathway.

CONCLUSIONS

This preliminary study suggests that viral and pneumococcal pneumonia differently affect the systemic metabolome, with a stronger disruption of the adrenal steroid pathway in pneumococcal pneumonia. This finding may lead to the discovery of novel diagnostic biomarkers and bring us closer to personalized therapy for pCAP.

Sepsis-associated encephalopathy: a vicious cycle of immunosuppression

Sepsis-associated encephalopathy (SAE) is commonly complicated by septic conditions, and is responsible for increased mortality and poor outcomes in septic patients. Uncontrolled neuroinflammation and ischemic injury are major contributors to brain dysfunction, which arises from intractable immune malfunction and the collapse of neuroendocrine immune networks, such as the cholinergic anti-inflammatory pathway, hypothalamic-pituitary-adrenal axis, and sympathetic nervous system. Dysfunction in these neuromodulatory mechanisms compromised by SAE jeopardizes systemic immune responses, including those of neutrophils, macrophages/monocytes, dendritic cells, and T lymphocytes, which ultimately results in a vicious cycle between brain injury and a progressively aberrant immune response. Deep insight into the crosstalk between SAE and peripheral immunity is of great importance in extending the knowledge of the pathogenesis and development of sepsis-induced immunosuppression, as well as in exploring its effective remedies.

Immune-neuroendocrine and metabolic disorders in human and experimental T. cruzi infection: New clues for understanding Chagas disease pathology

Studies in mice undergoing acute Trypanosoma cruzi infection and patients with Chagas disease, led to identify several immune-neuroendocrine disturbances and metabolic disorders. Here, we review relevant findings concerning such abnormalities and discuss their possible influence on disease physiopathology.

"Shanghuo" increases disease susceptibility: Modern significance of an old TCM theory

ETHNOPHARMACOLOGICAL RELEVANCE

"Shanghuo", a concept based on Traditional Chinese Medicine (TCM) theory, describes a status of Yin-Yang imbalance when Yang overwhelms Yin. The imbalance of Yin-Yang resembles the breaking of homeostasis and manifests by the impaired physiological functions, which leads to the onset, recurrence, and progression of diseases. Since ancient times, Chinese Materia Medica (CMM), such as herbal tea, has been applied as a treatment for "Shanghuo".

AIM OF THE STUDY

This review is aimed to describe the origin of "Shanghuo" from the Yin-Yang theory in TCM, as well as explore the relevance and correlations between "Shanghuo" and diseases susceptibility from the perspective of modern medicine. We also propose several strategies from CMM to improve the status of "Shanghuo" for the purpose of treating diseases.

METHODS

Systematic research of articles with keywords including Shanghuo, Yin-Yang, emotional stress and disease susceptibility was done by using the literature databases (Web of Science, Google Scholar, PubMed, CNKI). Related books, PhD and master's dissertations were also researched. Full scientific plant names were validated by "The Plant List" (www.theplantlist.org).

RESULTS

To date, a large number of publications have reported research on sub-health status, but studies about the theory or intervention of "Shanghuo" are rarely found. The articles we reviewed indicate that accumulated emotional stress is critical for the cause of "Shanghuo". As a status similar to sub-health, "Shanghuo" is also manifested by impaired physiological functions and decreased nonspecific resistance, which increase susceptibility to various diseases. What's more, some studies highlight the importance of TCM treatment towards "Shanghuo" in maintaining normal physiological functions, such as immunity, lipid metabolism and ROS clearance.

CONCLUSIONS

Researches on "Shanghuo" and its mechanism are every rare currently and are in need of investigation in the future. Studies on disease susceptibility recently are mostly about susceptible genes that relate to a few parts of people, however, for most of the people, accumulated emotional stress or other stressors is accountable for the susceptibility of diseases. Given that emotional stress plays an important factor in the causation of "Shanghuo", we reviewed the articles about this relevance and discussed the connection of "Shanghuo" with disease susceptibility in a novel perspective. In addition, we have reviewed the disease susceptibility model of restraint stress from its biochemical manifestation to application in CMM assessment. Although it would be a breakthrough in evaluating CMM efficacy of attenuating disease-susceptibility, understanding the comprehensive theory and establishing more models of "Shanghuo" would be required in further investigation.

An enlarged left adrenal gland is an indirect sign of infection on 18F-FDG PET/CT

OBJECTIVES

To determine whether hypermetabolisms of the spleen and bone marrow and an enlarged adrenal gland are significant indirect signs of infection on fluorine-18-fluorodeoxyglucose (F-FDG) PET/CT performed in patients with known or suspected infectious disease.

PATIENTS AND METHODS

Potential indirect signs of infection were as follows: (i) investigated in a retrospectively selected group of patients referred to F-FDG PET/CT for a known or suspected infectious disease and among whom the presence or absence of infectious foci was ascertained in 43 and 12 cases, respectively, and (ii) further validated in groups prospectively constituted of 12 patients with severe sepsis and of 39 control patients with no sign of any infectious disease. Standardised uptake values were determined on left adrenal gland, spleen and bone marrow, whereas the size of left adrenal gland was assessed by its maximal surface on unenhanced axial computed tomography (CT) slices.

RESULTS

Only the maximal surface of the left adrenal gland was a predictor in the initial study group (infection: 2.72±0.99 cm vs. no infection: 1.85±0.76 cm, P=0.004) and further validation groups (sepsis: 2.79±0.83 cm vs. controls: 1.91±0.67 cm, P=0.001). Patients with a greater than 1.8 cm maximal surface had more than two-fold higher infection rate than the other patients in the initial study group [88 (36/41) vs. 36% (4/11), P=0.001], even when only considering the subgroup with no evident infectious focus on F-FDG PET/CT [76 (16/21) vs. 30% (3/10), P=0.02].

CONCLUSION

An enlarged left adrenal gland is a significant sign of infection on F-FDG PET/CT, even in the absence of any evident infectious focus on F-FDG PET/CT images.

The Pathogenesis of Sepsis and Potential Therapeutic Targets

Sepsis is defined as “a life-threatening organ dysfunction caused by a host’s dysfunctional response to infection”. Although the treatment of sepsis has developed rapidly in the past few years, sepsis incidence and mortality in clinical treatment is still climbing. Moreover, because of the diverse manifestations of sepsis, clinicians continue to face severe challenges in the diagnosis, treatment, and management of patients with sepsis. Here, we review the recent development in our understanding regarding the cellular pathogenesis and the target of clinical diagnosis of sepsis, with the goal of enhancing the current understanding of sepsis. The present state of research on targeted therapeutic drugs is also elaborated upon to provide information for the treatment of sepsis.

Cortisol, progesterone, 17α-hydroxyprogesterone, and TSH responses in dogs injected with low-dose lipopolysaccharide

Background

Stress and diseases such as endotoxemia induce cortisol synthesis through a complex biosynthetic pathway involving intermediates (progesterone, and 17α-hydroxyprogesterone (17α-OHP)) and suppression of the hypothalamus-pituitary-thyroid axis.

Objective

To measure plasma concentrations of cortisol, progesterone, 17α-OHP, and thyroid stimulating hormone (TSH) in dogs experimentally injected with intravenous low-dose lipopolysaccharide (LPS). Our hypothesis was that LPS treatment would elicit a significant increase in cortisol and its precursors, and a significant decrease in TSH concentration.

Methods

Hormone measurements were performed on blood samples left over from a previous investigation (2011) on the effect of low-dose LPS on hematological measurands. Five sexually intact female dogs, none in estrous at the time of the study, were administered saline treatment two weeks prior to LPS treatment. LPS was administered intravenously at a dose of 0.1 µg/kg. Blood was collected before (baseline, time -24 hours) and 3-, 6- and 24-hours post-injection. Mixed model analysis for repeated measures was used, with both treatment and time as the repeated factors. Ranked transformation were applied when diagnostic analysis exhibited violation of normality and equal variance assumptions. Post hoc multiple comparisons were performed with Tukey’s adjustment. Statistical significance was defined as p < 0.05.

Results

Significant differences relative to baseline values were detected following both treatments. Compared to baseline, dogs had significantly higher cortisol and 17α-OHP at 3-hours, and significantly lower TSH at 3- and 6-hours following LPS treatment. Dogs had significantly lower TSH at 6- and 24- following saline treatment. Though not statistically significant, the trend in progesterone concentrations was similar to cortisol and 17α-OHP, with an increase at 3-hours post-injection followed by a decrease close to baseline following both LPS and saline. Cortisol and 17α-OHP concentrations were higher after LPS treatment than after saline treatment at 3- and 6-hours post-injection, but differences were not statistically significant, and no significant differences between treatments were detected for any other hormone or timepoint.

Discussion and conclusion

Cortisol and its adrenal precursors are released in the bloodstream following a low dose of LPS, while TSH appears to decrease. Similar changes occurred following saline treatment, suggesting that even routine handling and saline injection in conditioned dogs can elicit alterations in the internal equilibrium with subsequent modification of both hypothalamus-pituitary-adrenal and thyroid axes. Changes to adrenal and thyroid hormone concentrations must be interpreted in light of clinical information. Further studies are needed to elucidate mechanisms of adrenal steroidal hormone synthesis and secretion in response to various stressful stimuli in both neutered and intact animals.

RNA-seq analysis of LPS-induced transcriptional changes and its possible implications for the adrenal gland dysregulation during sepsis

Activation of the adrenal gland stress response is of utmost importance to survive sepsis. Experimental and clinical evidence exists demonstrating that adrenal gland often develops functional and structural damage due to sepsis with mechanisms remaining largely unknown. In the present study, we have used RNA Sequencing (RNA-Seq) technology to analyze changes in adrenal transcriptome elucidated by bacterial LPS. We aimed to find particularly alterations in genes that were previously not reported to be involved in the adrenal gland dysregulation in contexts of sepsis. Our results demonstrate that systemic administration of LPS significantly altered expression of 8458 genes as compared to saline injected animals. The subsequent quality and functional analysis of these gene signatures revealed that LPS-induced highly homogenous transcriptional response in total upregulating 4312 and downregulating 4146 genes. Furthermore, functional annotation analysis together with gene enrichment set analysis (GSEA) clearly demonstrated that adrenal response to LPS involved alterations in multiple pathways related to the inflammatory response along with previously unexplored activation of the hypoxia pathway. In addition, LPS strongly downregulated genes involved in the adrenal homeostasis, development, and regeneration. Those alterations were subsequently verified in clinically relevant cecal ligation and puncture (CLP)-induced sepsis model. Collectively, our study demonstrates that RNA-seq is a very useful method that can be applied to search for new unexplored pathways potentially involved in adrenal gland dysregulation during sepsis.

Capsaicin inhibits lipopolysaccharide-induced adrenal steroidogenesis by raising intracellular calcium levels

INTRODUCTION

Glucocorticoid release by adrenals has been described as significant to survive sepsis. The activation of transient receptor potential vanilloid type 1 (TRPV1) inhibited ACTH-induced glucocorticoid release by adrenal glands in vitro.

OBJECTIVE

The aim of this study was to investigate if capsaicin, an activator of TRPV1, would prevent LPS-induced glucocorticoid production by adrenals.

METHODS

Male Swiss-Webster mice were treated with capsaicin intraperitoneally (0.2 or 2 mg/kg) 30 min before LPS injection. All analyses were performed 2 h after the LPS stimulation, including plasma corticosterone and peritoneal IL-1β and TNF-α levels. Furthermore, murine adrenocortical Y1 cells were used to assess the effects of capsaicin on LPS-induced corticosterone production in vitro.

RESULTS

Capsaicin (2 mg/kg, i.p.) significantly reduced plasma corticosterone levels and adrenal hypertrophy induced by LPS without alter the levels of pro-steroidogenic cytokines IL-1β and TNF-α in peritoneal cavity of mice, while the dose of 0.2 mg/kg of capsaicin did not interfere with adrenal steroidogenesis, attested by RIA and ELISA, respectively. Y1 cells express TRPV1, measured by immunofluorescence and western blot, and capsaicin decreased LPS-induced corticosterone production by these cells in vitro. Capsaicin also induces calcium mobilization in Y1 cells in vitro.

CONCLUSIONS

These findings suggest that capsaicin inhibits corticosterone production induced by LPS by acting directly on adrenal cells producing glucocorticoids, in a mechanism probably associated with induction of a cytoplasmic calcium increase in these cells.

The hollow adrenal gland sign: a newly described enhancing pattern of the adrenal gland on dual-phase contrast-enhanced CT for predicting the prognosis of patients with septic shock

OBJECTIVE

To investigate the incidence, CT appearance, and implication for prognosis of the hollow adrenal gland sign (HAGS).

METHODS

A total of 194 patients with septic shock and 24 patients with hemorrhagic shock (as control group) were retrospectively included in this study and the patients with septic shock were further divided into four subgroups (digestive tract diseases, DTD, n = 49; biliary and pancreatic diseases, BPD, n = 41; postsurgical infection, PI, n = 64; and other diseases, OD, n = 40). All patients underwent a dual-phase contrast-enhanced CT within 1 week after diagnosis. CT findings and clinical records were reviewed. If in the arterial phase the central zone of adrenal gland showed temporally much lower attenuation than the peripheral zone, it was defined as HAGS positive. The incidence of the HAGS in patients with septic shock and hemorrhagic shock, the demographic features, and mortality between HAGS-positive and HAGS-negative patients in each group were respectively compared.

RESULTS

The incidence of the HAGS in the septic shock group was nearly 30%, while it was 0 in the hemorrhagic shock group. There was no significant difference in age or gender between HAGS-positive and HAGS-negative patients in all groups, while the mortality of HAGS-positive patients was significantly higher than that of HAGS-negative patients in each group (p < 0.05). The concordance correlation coefficient value showed excellent reproducibility of the two observers (κ = 0.977).

CONCLUSION

The HAGS is specific and common on dual-phase contrast-enhanced CT in patients with septic shock and predicts a poor prognosis.

KEY POINTS

• The hollow adrenal gland sign (HAGS) newly described in this study is a special enhancing pattern of adrenal gland on dual-phase contrast-enhanced CT in patients with septic shock. • The HAGS is characterized by the much lower-attenuated central zone of the adrenal gland in arterial phase and it showed excellent reproducibility between different observers. • The HAGS is specific and common on dual-phase contrast-enhanced CT in patients with septic shock and predicts a poor prognosis.

Evidence in Favor of an Alternative Glucocorticoid Synthesis Pathway During Acute Experimental Chagas Disease

It is well-established that infectious stress activates the hypothalamus-pituitary-adrenal axis leading to the production of pituitary adrenocorticotropin (ACTH) and adrenal glucocorticoids (GCs). Usually, GC synthesis is mediated by protein kinase A (PKA) signaling pathway triggered by ACTH. We previously demonstrated that acute murine Chagas disease courses with a marked increase of GC, with some data suggesting that GC synthesis may be ACTH-dissociated in the late phase of this parasitic infection. Alternative pathways of GC synthesis have been reported in sepsis or mental diseases, in which interleukin (IL)-1β, prostaglandin E2 (PGE2), and/or cAMP-activated guanine nucleotide exchange factor 2 (EPAC2) are likely to play a role in this regard. Accordingly, we have searched for the existence of an ACTH-independent pathway in an experimental model of a major parasitic disease like Chagas disease, in addition to characterizing potential alternative pathways of GC synthesis. To this end, C57BL/6 male mice were infected with T. cruzi (Tc), and evaluated throughout the acute phase for several parameters, including the kinetic of GC and ACTH release, the adrenal level of MC2R (ACTH receptor) expression, the p-PKA/PKA ratio as ACTH-dependent mechanism of signal transduction, as well as adrenal expression of IL-1β and its receptor, EPAC2 and PGE2 synthase. Our results reveal the existence of two phases involved in GC synthesis during Tc infection in mice, an initial one dealing with the well-known ACTH-dependent pathway, followed by a further ACTH-hyporesponsive phase. Furthermore, inflamed adrenal microenvironment may tune the production of intracellular mediators that also operate upon GC synthesis, like PGE2 synthase and EPAC2, as emerging driving forces for GC production in the advanced course of Tc infection. In essence, GC production seems to be associated with a biphasic action of PGE2, suggesting that the effect of PGE2/cAMP in the ACTH-independent second phase may be mediated by EPAC2.

Transcriptional Analysis of Sepsis-Induced Activation and Damage of the Adrenal Endothelial Microvascular Cells

Bacterial sepsis is a serious threat to the body homeostasis and is often associated with high mortality in non-coronary intensive stations. In order to survive sepsis, rapid activation of the hypothalamus-pituitary-adrenal gland axis and sympathomedullary system is necessary. In many patients with sepsis, the function of those two arms of the stress system is dysregulated with underlying mechanisms remaining unknown. In our previous experimental studies, we have demonstrated that LPS-induced systemic inflammation and CLP-induced peritonitis can result in adrenal gland damage. Histological and transcriptomic analysis revealed a potential involvement of the adrenal microvascular endothelium in this process. However, our knowledge about the function of adrenal microvascular cells during sepsis is scarce. In the present study, we have characterized transcriptomic alterations in isolated mouse adrenal microvascular endothelial cells induced by systemic administration of bacterial LPS. Our results revealed that LPS induced a distinct transcriptomic profile in the adrenal microvascular cells, including multiple genes regulating inflammation, activation of the coagulation cascade and vascular permeability. Activation of those genes may be potentially involved in the damage to the microvascular endothelium and altogether contribute to the sepsis-mediated adrenal dysregulation.

Organ-specific response to nivolumab in patients with non-small cell lung cancer (NSCLC)

BACKGROUND

Response to immune checkpoint inhibitors depends on tumor intrinsic properties and also on host factors in the tumour microenvironment including the presence of immune cells (IC). We hypothesized that nivolumab efficacy varies across different metastatic sites.

METHODS

We retrospectively analyzed computed tomography scans of patients with metastatic non-small cell lung carcinoma (NSCLC) receiving nivolumab. RECIST 1.1 criteria were applied to assess the overall response rate (ORR) and organ-specific response rate (OSRR).

RESULTS

We analyzed 52 patients including 44% females, 58% adenocarcinoma and 8% never smokers. Involved organs had target-lesions in the lung (42%), liver (25%), lymph nodes (56%) and soft tissue (13%) and non-target lesions in the bones (23%). ORR and disease control rate (DCR) were 20% and 45%, respectively. Median overall survival, progression-free survival and duration of response were 11.9, 2.3 and 10.3 months. OSRR and organ-specific DCR (OSDCR) were 28% and 90% in lymph nodes, 8% and 54 in the liver, and 9% and 55% in lung metastases. Nine out of 12 patients with bone metastases had progressive lesions. The cumulative incidence probability of organ-specific progression at 6 months was 14% in lymph nodes, 42% in the liver, 36% in lung metastases and 26% in the primary tumor, 29% in soft tissue and 33% in adrenal metastases.

CONCLUSION

In conclusion, the efficacy of immunotherapy is dependent on the metastatic location. Treatment appears more active in lymph nodes compared to other organ sites such as liver, adrenals and bone. Future strategies may include additional local treatment in case of oligoprogression in these organs in patients with otherwise sustained treatment benefit.

Omega-9 Oleic Acid, the Main Compound of Olive Oil, Mitigates Inflammation during Experimental Sepsis

The Mediterranean diet, rich in olive oil, is beneficial, reducing the risk of cardiovascular diseases and cancer. Olive oil is mostly composed of the monounsaturated fatty acid omega-9. We showed omega-9 protects septic mice modulating lipid metabolism. Sepsis is initiated by the host response to infection with organ damage, increased plasma free fatty acids, high levels of cortisol, massive cytokine production, leukocyte activation, and endothelial dysfunction. We aimed to analyze the effect of omega-9 supplementation on corticosteroid unbalance, inflammation, bacterial elimination, and peroxisome proliferator-activated receptor (PPAR) gamma expression, an omega-9 receptor and inflammatory modulator. We treated mice for 14 days with omega-9 and induced sepsis by cecal ligation and puncture (CLP). We measured systemic corticosterone levels, cytokine production, leukocyte and bacterial counts in the peritoneum, and the expression of PPAR gamma in both liver and adipose tissues during experimental sepsis. We further studied omega-9 effects on leukocyte rolling in mouse cremaster muscle-inflamed postcapillary venules and in the cerebral microcirculation of septic mice. Here, we demonstrate that omega-9 treatment is associated with increased levels of the anti-inflammatory cytokine IL-10 and decreased levels of the proinflammatory cytokines TNF-α and IL-1β in peritoneal lavage fluid of mice with sepsis. Omega-9 treatment also decreased systemic corticosterone levels. Neutrophil migration from circulation to the peritoneal cavity and leukocyte rolling on the endothelium were decreased by omega-9 treatment. Omega-9 also decreased bacterial load in the peritoneal lavage and restored liver and adipose tissue PPAR gamma expression in septic animals. Our data suggest a beneficial anti-inflammatory role of omega-9 in sepsis, mitigating leukocyte rolling and leukocyte influx, balancing cytokine production, and controlling bacterial growth possibly through a PPAR gamma expression-dependent mechanism. The significant reduction of inflammation detected after omega-9 enteral injection can further contribute to the already known beneficial properties facilitated by unsaturated fatty acid-enriched diets.

The potential role for infections in the pathogenesis of autoimmune Addison's disease

Autoimmune Addison's disease (AAD), or primary adrenocortical insufficiency, is a classical organ-specific autoimmune disease with 160 years of history. AAD is remarkably homogeneous with one major dominant self-antigen, the cytochrome P450 21-hydroxylase enzyme, which is targeted by both autoantibodies and autoreactive T cells. Like most autoimmune diseases, AAD is thought to be caused by an unfortunate combination of genetic and environmental factors. While the number of genetic associations with AAD is increasing, almost nothing is known about environmental factors. A major environmental factor commonly proposed for autoimmune diseases, based partly on experimental and clinical data and partly on shared pathways between anti-viral immunity and autoimmunity, is viral infections. However, there are few reports associating viral infections to AAD, and it has proved difficult to establish which immunological processes that could link any viral infection with the initiation or progression of AAD. In this review, we will summarize the current knowledge on the underlying mechanisms of AAD and take a closer look on the potential involvement of viruses.

The clinical relevance of necroinflammation-highlighting the importance of acute kidney injury and the adrenal glands

Necroinflammation is defined as the inflammatory response to necrotic cell death. Different necrotic cell death pathways exhibit different immune reponses, despite a comparable level of intracellular content release (referred to as damage associated molecular patterns or DAMPs). In addition to DAMP release, which is inevitably associated with necrotic cell death, the active production of pro/anti-inflammatory cytokines characterizes certain necrotic pathways. Necroptosis, ferroptosis and pyroptosis, therefore, are immunogenic to a different extent. In this review, we discuss the clinical relevance of necroinflammation highlighting potential human serum markers. We focus on the role of the adrenal glands and the lungs as central organs affected by systemic and/or local DAMP release and underline their role in intensive care medicine. In addition, data from models of acute kidney injury (AKI) and kidney transplantation have significantly shaped the field of necroinflammation and may be helpful for the understanding of the potential role of dialysis and plasma exchange to treat ongoing necroinflammation upon intensive care unit (ICU) conditions. In conclusion, we are only beginning to understand the importance of necroinflammation in diseases and transplantation, including xenotransplantation. However, given the existing efforts to develop inhibitors of necrotic cell death (ferrostatins, necrostatins, etc), we consider it likely that interference with necroinflammation reaches clinical routine in the near future.

Circadian rhythms and rheumatoid arthritis

Circadian rhythms (Nobel prize for Medicine 2017) regulate, under action of biological clocks located both at the level of central nervous system and inside peripheral cells, several daily activities, embracing sleep, feeding times, energy metabolism, endocrine and immune functions with related pathological conditions, including rheumatoid arthritis (RA). In RA the circadian rhythms impact on cellular functions, involving night synthesis and release of pro-inflammatory cytokines and chemokines, cell migration to inflamed tissues, phagocytosis, proliferative cell response and all are peaking at late night. In chronic inflammatory conditions such as RA, the amplitude of the circadian rhythm of the anti-inflammatory endogenous cortisol availability is not increased as expected and requested, which indicate a reduced night cortisol secretion under the adrenal chronic stress induced by the disease. Therefore, the prevention/treatment of the immune cell night hyperactivity, with related flare of cytokine synthesis and morning RA clinical symptoms, has been shown more effective when the availability of the exogenous glucocorticoids is obtained in the middle of the night (night release). The impressive positive results observed in RA patients treated with modified-night release prednisone with a low-dose chronotherapy, seem applicable even for other agents such as conventional NSAIDs and DMARDs, including the positive experimental and clinical results obtained by the night time daily administration of methotrexate. Interestingly, a very recent study showed that methotrexate upregulates important cell circadian genes, resulting in induction of apoptosis in synovial fibroblasts. The link between the circadian rhythms of the disease and the chronotherapy of RA is promising.

Involvement of adenosine monophosphate activated kinase in interleukin-6 regulation of steroidogenic acute regulatory protein and cholesterol side chain cleavage enzyme in the bovine zona fasciculata and zona reticularis

In bovine adrenal zona fasciculata (ZF) and NCI-H295R cells, interleukin-6 (IL-6) increases cortisol release, increases expression of steroidogenic acute regulatory protein (StAR), cholesterol side chain cleavage enzyme (P450scc), and steroidogenic factor 1 (SF-1) (increases steroidogenic proteins), and decreases the expression of adrenal hypoplasia congenita-like protein (DAX-1) (inhibits steroidogenic proteins). In contrast, IL-6 decreases bovine adrenal zona reticularis (ZR) androgen release, StAR, P450scc, and SF-1 expression, and increases DAX-1 expression. Adenosine monophosphate (AMP) activated kinase (AMPK) regulates steroidogenesis, but its role in IL-6 regulation of adrenal steroidogenesis is unknown. In the present study, an AMPK activator (AICAR) increased (P < 0.01) NCI-H295R StAR promoter activity, StAR and P450scc expression, and the phosphorylation of AMPK (PAMPK) and acetyl-CoA carboxylase (PACC) (indexes of AMPK activity). In ZR (decreased StAR, P450scc, SF-1, increased DAX-1) (P < 0.01) and ZF tissues (increased StAR, P450scc, SF-1, decreased DAX-1) (P < 0.01), AICAR modified StAR, P450scc, SF-1 and DAX-1 mRNAs/proteins similar to the effects of IL-6. The activity (increased PAMPK and PACC) (P < 0.01) of AMPK in the ZF and ZR was increased by AICAR and IL-6. In support of an AMPK role in IL-6 ZF and ZR effects, the AMPK inhibitor compound C blocked (P < 0.01) the effects of IL-6 on the expression of StAR, P450scc, SF-1, and DAX-1. Therefore, IL-6 modification of the expression of StAR and P450scc in the ZF and ZR may involve activation of AMPK and these changes may be related to changes in the expression of SF-1 and DAX-1.