Serum Amyloid A Production Is Triggered by Sleep Deprivation in Mice and Humans: Is That the Link between Sleep Loss and Associated Comorbidities?

Podoplanin Positive Cell-derived Extracellular Vesicles Contribute to Cardiac Amyloidosis After Myocardial Infarction

Background

Amyloidosis is a major long-term complication of chronic disease; however, whether it represents one of the complications of post-myocardial infarction (MI) is yet to be fully understood.

Methods

Using wild-type and knocked-out MI mouse models and characterizing in vitro the exosomal communication between bone marrow-derived macrophages and activated mesenchymal stromal cells (MSC) isolated after MI, we investigated the mechanism behind Serum Amyloid A 3 (SAA3) protein overproduction in injured hearts.

Results

Here, we show that amyloidosis occurs after MI and that amyloid fibers are composed of macrophage-derived SAA3 monomers. SAA3 overproduction in macrophages is triggered by exosomal communication from a subset of activated MSC, which, in response to MI, acquire the expression of a platelet aggregation-inducing type I transmembrane glycoprotein named Podoplanin (PDPN). Cardiac MSC PDPN+ communicate with and activate macrophages through their extracellular vesicles or exosomes. Specifically, MSC PDPN+ derived exosomes (MSC PDPN+ Exosomes) are enriched in SAA3 and exosomal SAA3 protein engages with Toll-like receptor 2 (TRL2) on macrophages, triggering an overproduction and impaired clearance of SAA3 proteins, resulting in aggregation of SAA3 monomers as rigid amyloid deposits in the extracellular space. The onset of amyloid fibers deposition alongside extra-cellular-matrix (ECM) proteins in the ischemic heart exacerbates the rigidity and stiffness of the scar, hindering the contractility of viable myocardium and overall impairing organ function. Using SAA3 and TLR2 deficient mouse models, we show that SAA3 delivered by MSC PDPN+ exosomes promotes post-MI amyloidosis. Inhibition of SAA3 aggregation via administration of a retro-inverso D-peptide, specifically designed to bind SAA3 monomers, prevents the deposition of SAA3 amyloid fibrils, positively modulates the scar formation, and improves heart function post-MI.

Conclusion

Overall, our findings provide mechanistic insights into post-MI amyloidosis and suggest that SAA3 may be an attractive target for effective scar reversal after ischemic injury and a potential target in multiple diseases characterized by a similar pattern of inflammation and amyloid deposition.

NOVELTY AND SIGNIFICANCE

What is known? Accumulation of rigid amyloid structures in the left ventricular wall impairs ventricle contractility.After myocardial infarction cardiac Mesenchymal Stromal Cells (MSC) acquire Podoplanin (PDPN) to better interact with immune cells.Amyloid structures can accumulate in the heart after chronic inflammatory conditions. What information does this article contribute? Whether accumulation of cumbersome amyloid structures in the ischemic scar impairs left ventricle contractility, and scar reversal after myocardial infarction (MI) has never been investigated.The pathophysiological relevance of PDPN acquirement by MSC and the functional role of their secreted exosomes in the context of post-MI cardiac remodeling has not been investigated.Amyloid structures are present in the scar after ischemia and are composed of macrophage-derived Serum Amyloid A (SAA) 3 monomers, although mechanisms of SAA3 overproduction is not established.

SUMMARY OF NOVELTY AND SIGNIFICANCE

Here, we report that amyloidosis, a secondary phenomenon of an already preexisting and prolonged chronic inflammatory condition, occurs after MI and that amyloid structures are composed of macrophage-derived SAA3 monomers. Frequently studied cardiac amyloidosis are caused by aggregation of immunoglobulin light chains, transthyretin, fibrinogen, and apolipoprotein in a healthy heart as a consequence of systemic chronic inflammation leading to congestive heart failure with various types of arrhythmias and tissue stiffness. Although chronic MI is considered a systemic inflammatory condition, studies regarding the possible accumulation of amyloidogenic proteins after MI and the mechanisms involved in that process are yet to be reported. Here, we show that SAA3 overproduction in macrophages is triggered in a Toll-like Receptor 2 (TLR2)-p38MAP Kinase-dependent manner by exosomal communication from a subset of activated MSC, which, in response to MI, express a platelet aggregation-inducing type I transmembrane glycoprotein named Podoplanin. We provide the full mechanism of this phenomenon in murine models and confirm SAA3 amyloidosis in failing human heart samples. Moreover, we developed a retro-inverso D-peptide therapeutic approach, "DRI-R5S," specifically designed to bind SAA3 monomers and prevent post-MI aggregation and deposition of SAA3 amyloid fibrils without interfering with the innate immune response.

Human serum proteomics reveals a molecular signature after one night of sleep deprivation

Study Objectives

Sleep deprivation is highly prevalent and caused by conditions such as night shift work or illnesses like obstructive sleep apnea. Compromised sleep affects cardiovascular-, immune-, and neuronal systems. Recently, we published human serum proteome changes after a simulated night shift. This pilot proteomic study aimed to further explore changes in human blood serum after 6 hours of sleep deprivation at night.

Methods

Human blood serum samples from eight self-declared healthy females were analyzed using Orbitrap Eclipse mass spectrometry (MS-MS) and high-pressure liquid chromatography. We used a within-participant design, in which the samples were taken after 6 hours of sleep at night and after 6 hours of sleep deprivation the following night. Systems biological databases and bioinformatic software were used to analyze the data and comparative analysis were done with other published sleep-related proteomic datasets.

Results

Out of 494 proteins, 66 were found to be differentially expressed proteins (DEPs) after 6 hours of sleep deprivation. Functional enrichment analysis revealed the associations of these DEPs with several biological functions related to the altered regulation of cellular processes such as platelet degranulation and blood coagulation, as well as associations with different curated gene sets.

Conclusions

This study presents serum proteomic changes after 6 hours of sleep deprivation, supports previous findings showing that short sleep deprivation affects several biological processes, and reveals a molecular signature of proteins related to pathological conditions such as altered coagulation and platelet function, impaired lipid and immune function, and cell proliferation. Data are available via ProteomeXchange with identifier PXD045729. This paper is part of the Genetic and other molecular underpinnings of sleep, sleep disorders, and circadian rhythms including translational approaches Collection.

Serum amyloid A and metabolic disease: evidence for a critical role in chronic inflammatory conditions

Serum amyloid A (SAA) subtypes 1-3 are well-described acute phase reactants that are elevated in acute inflammatory conditions such as infection, tissue injury, and trauma, while SAA4 is constitutively expressed. SAA subtypes also have been implicated as playing roles in chronic metabolic diseases including obesity, diabetes, and cardiovascular disease, and possibly in autoimmune diseases such as systemic lupus erythematosis, rheumatoid arthritis, and inflammatory bowel disease. Distinctions between the expression kinetics of SAA in acute inflammatory responses and chronic disease states suggest the potential for differentiating SAA functions. Although circulating SAA levels can rise up to 1,000-fold during an acute inflammatory event, elevations are more modest (∼5-fold) in chronic metabolic conditions. The majority of acute-phase SAA derives from the liver, while in chronic inflammatory conditions SAA also derives from adipose tissue, the intestine, and elsewhere. In this review, roles for SAA subtypes in chronic metabolic disease states are contrasted to current knowledge about acute phase SAA. Investigations show distinct differences between SAA expression and function in human and animal models of metabolic disease, as well as sexual dimorphism of SAA subtype responses.

Sleep Deprivation and Gut Microbiota Dysbiosis: Current Understandings and Implications

Gut microbiota comprises the microbial communities inhabiting our gastrointestinal (GI) tracts. Accordingly, these complex communities play a fundamental role in many host processes and are closely implicated in human health and diseases. Sleep deprivation (SD) has become increasingly common in modern society, partly owing to the rising pressure of work and the diversification of entertainment. It is well documented that sleep loss is a significant cause of various adverse outcomes on human health including immune-related and metabolic diseases. Furthermore, accumulating evidence suggests that gut microbiota dysbiosis is associated with these SD-induced human diseases. In this review, we summarize the gut microbiota dysbiosis caused by SD and the succedent diseases ranging from the immune system and metabolic system to various organs and highlight the critical roles of gut microbiota in these diseases. The implications and possible strategies to alleviate SD-related human diseases are also provided.

Nanowired Delivery of Cerebrolysin Together with Antibodies to Amyloid Beta Peptide, Phosphorylated Tau, and Tumor Necrosis Factor Alpha Induces Superior Neuroprotection in Alzheimer's Disease Brain Pathology Exacerbated by Sleep Deprivation

Sleep deprivation induces amyloid beta peptide and phosphorylated tau deposits in the brain and cerebrospinal fluid together with altered serotonin metabolism. Thus, it is likely that sleep deprivation is one of the predisposing factors in precipitating Alzheimer's disease (AD) brain pathology. Our previous studies indicate significant brain pathology following sleep deprivation or AD. Keeping these views in consideration in this review, nanodelivery of monoclonal antibodies to amyloid beta peptide (AβP), phosphorylated tau (p-tau), and tumor necrosis factor alpha (TNF-α) in sleep deprivation-induced AD is discussed based on our own investigations. Our results suggest that nanowired delivery of monoclonal antibodies to AβP with p-tau and TNF-α induces superior neuroprotection in AD caused by sleep deprivation, not reported earlier.

Sleep quality traits correlate with inflammatory markers in the breast tissue of women

BACKGROUND

Several mechanisms have been posited to play a role in the sleep and breast cancer association, including alterations in immune function, but evidence remains inconclusive. A closer look at how sleep quality traits affect the breast microenvironment may provide clues for molecular mechanisms underlying the link between sleep and breast cancer. We examined the association between sleep quality traits (sleep duration, sleep aids, and insomnia) and tissue-based protein levels and gene expression of several inflammatory markers associated with breast cancer.

METHODS

Breast tissues (normal n = 165 and adipose n = 74) were surgically obtained from women diagnosed with breast cancer. Protein levels by immunohistochemistry were determined using the quickscore method for 11 inflammatory markers in the normal epithelial breast tissue (interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), cyclooxygenase-2 (COX-2), leptin, serum amyloid A1 (SAA1), lactoferrin, transforming growth factor-beta (TGF-β), and signal transducer and activator of transcription 3 markers (STAT3). Relative quantification of 4 genes (COX-2, IL-6, TNF-α and LEP) in the adipose breast tissue was carried out using qPCR. Patient characteristics and sleep traits (average sleep duration per night, taking sleeping aids in the past year, and the average number of insomnia episodes per month) were determined by telephone interview. Associations were tested using Spearman's rank correlation (r_s) coefficients adjusted (ar_s) for age at surgery, menopausal status and PCR batch when applicable. Sleep duration categories (<7, 7-9, >9 h) and root- or log-transformed biomarker levels were examined with adjusted linear mixed models.

RESULTS

TGF-β and CRP levels in normal epithelial breast tissue were positively correlated with sleep aids (ar_s = 0.28, p = 0.013), and insomnia (ar_s = 0.23, p = 0.044) in postmenopausal women, respectively. IL-6 in the adipose breast tissue was inversely correlated with sleep aids (ar_s = -0.26, p = 0.029) in all women. None of the sleep traits significantly correlated with inflammatory markers in premenopausal women. Several markers tended to correlate at 0.05 ≥ p ≤ 0.10. Adjusted mean levels of inflammatory markers were significantly different across sleep duration categories (<7, 7-9, >9 h). Higher mean levels of IL-6, CRP, IL-10, and IL-6 and COX-2 expression were noted in the breast tissues of women sleeping < 7, and particularly, >9 h per night (p < 0.05).

CONCLUSION

Our findings indicate that sleep duration, sleep aids, and insomnia may differently affect women's breast tissues depending on menopausal status. From a public health perspective, these results warrant further validation in larger studies. Since sleep is a modifiable factor, it may be an interesting approach for breast cancer prevention.

Does Insufficient Sleep Increase the Risk of Developing Insulin Resistance: A Systematic Review

It has been recommended that adults sleep a minimum of seven hours of sleep every night to maintain holistic health and well-being. A considerable fraction of the adult population suffers from sleep deprivation and related disorders. The stress of modern-day living may be the cause of this curtailment of sleep duration. The primary purpose of this study was to investigate the effects of reduced sleep on the development of insulin resistance and explore the possible mechanisms linking the two. We utilized databases like such as PubMed, PubMed Central (PMC), and Medical Literature Analysis and Retrieval System Online (MEDLINE) to systematically screen papers using keywords and Medical Subject Heading (MeSH) terms. A few articles were also retrieved from Cochrane Library. We applied inclusion/exclusion criteria after screening papers via title and abstracts. A quality appraisal check was doneperformed, and ten 10 related studies were strictly reviewed.

Short sleep duration was significantly associated with insulin resistance. Inflammatory markers such as C-reactive protein (CRP) and serum amyloid A (SAA), biomarkers such as glucagon-like peptide-1 (GLP-1), and circadian misalignment may play a significant role in the pathogenesis of this association. To prevent metabolic complications such as type- 2 diabetes, adequate sleep (more than seven hours per night) is required in the adult population. The causal relationship between sleep deprivation and insulin resistance is multifactorial, and further studies are warranted to understand these mechanisms better.

Acute Inflammation Is a Predisposing Factor for Weight Gain and Insulin Resistance

In the course of infection and intense endotoxemia processes, induction of a catabolic state leading to weight loss is observed in mice and humans. However, the late effects of acute inflammation on energy homeostasis, regulation of body weight and glucose metabolism are yet to be elucidated. Here, we addressed whether serial intense endotoxemia, characterized by an acute phase response and weight loss, could be an aggravating or predisposing factor to weight gain and associated metabolic complications. Male Swiss Webster mice were submitted to 8 consecutive doses of lipopolysaccharide (10 mg/kg LPS), followed by 10 weeks on a high-fat diet (HFD). LPS-treated mice did not show changes in weight when fed standard chow. However, when challenged by a high-fat diet, LPS-treated mice showed greater weight gain, with larger fat depot areas, increased serum leptin and insulin levels and impaired insulin sensitivity when compared to mice on HFD only. Acute endotoxemia caused a long-lasting increase in mRNA expression of inflammatory markers such as TLR-4, CD14 and serum amyloid A (SAA) in the adipose tissue, which may represent the key factors connecting inflammation to increased susceptibility to weight gain and impaired glucose homeostasis. In an independent experimental model, and using publicly available microarray data from adipose tissue from mice infected with Gram-negative bacteria, we performed gene set enrichment analysis and confirmed upregulation of a set of genes responsible for cell proliferation and inflammation, including TLR-4 and SAA. Together, we showed that conditions leading to intense and recurring endotoxemia, such as common childhood bacterial infections, may resound for a long time and aggravate the effects of a western diet. If confirmed in humans, infections should be considered an additional factor contributing to obesity and type 2 diabetes epidemics.

Serum amyloid A in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), i.e., anovulation, hyperandrogenemia and polycystic ovary, is an endocrine-metabolic disease affecting reproductive aged women. Women with PCOS are likely to develop obesity, dyslipidemia, type 2 diabetes mellitus (T2DM) and cardiovascular diseases at a younger age. Despite high frequency and severe disease burden, the pathophysiological mechanisms of PCOS remain poorly defined and correspondingly have no therapeutic options. Emerging evidence has demonstrated that PCOS is accompanied with low-grade chronic inflammation and biomarkers thereof. Interestingly, serum amyloid A (SAA) has recently been identified as a potential marker of infection and inflammation and a number of studies have reported an association with PCOS. In this review, we explore the relationship between SAA and hyperandrogenemia, inflammation, obesity and insulin resistance, and provide convincing evidence for SAA as a potential inflammatory biomarker in PCOS.

Relationships Between a Range of Inflammatory Biomarkers and Subjective Sleep Quality in Chronic Insomnia Patients: A Clinical Study

PURPOSE

To examine whether associations exist between chronic insomnia disorder (CID) and overlooked inflammatory factors (Serum amyloid protein A [SAA]), tumor necrosis factor [TNF]-α, granulocyte-macrophage colony-stimulating factor [GM-CSF], and regulated on activation and normal T cell expressed and presumably secreted [RANTES]).

PATIENTS AND METHODS

A total of 65 CID patients and 39 sex- and age-matched good sleeper (GS) controls participated in this study. They completed a baseline survey to collect data on demographics, and were elevated sleep and mood by Pittsburgh Sleep Quality Index (PSQI), Athens Insomnia Scale (AIS), 17-item Hamilton Depression Rating Scale (HAMD-17) and 14-item Hamilton Anxiety Rating Scale (HAMA-14), respectively. The blood samples were collected and tested the serum levels of SAA, TNF-α, GM-CSF and RANTES.

RESULTS

The CID group had higher serum levels of SAA, TNF-α, and GM-CSF and a lower level of RANTES than the GS group. In the Spearman correlation analysis, SAA and GM-CSF positively correlated with the PSQI and AIS scores. After controlling for sex, HAMD-17 score, and HAMA-14 score, the partial correlation analysis showed that GM-CSF was positively correlated with PSQI score. Further stepwise linear regression analyses showed that GM-CSF was positively associated with the PSQI and AIS scores, while RANTES was negatively associated with them, and SAA was positively associated with just the AIS score.

CONCLUSION

The serum levels of inflammatory mediators (SAA, TNF-α, and GM-CSF) were significantly elevated and the level of RANTES was significantly decreased in CID patients and, to some extent, the changes are related to the severity of insomnia. These findings may help us to improve interventions to prevent the biological consequences of CID by inhibiting inflammation, thereby promoting health.

Invariant Natural Killer T cells resilience to paradoxical sleep deprivation-associated stress

Although several studies demonstrate that stressful situations, such as sleep disturbances, negatively impact the innate and adaptive arms of the immune system, their influence on invariant Natural Killer T (iNKT) cells remains unclear. iNKT cells are CD1d-restricted innate T cells that recognize glycolipid antigens and rapidly produce polarizing cytokines being key players in several immune responses, and a potential target for immunotherapy. iNKT cells differ in several aspects from conventional T lymphocytes, including a unique dependence on CD1d-expressing double-positive (DP) thymocytes for intrathymic maturation. As a consequence of stress, DP thymocytes undergo glucocorticoid-induced apoptosis, which might compromise iNKT developmental pathway. Therefore, we used a paradoxical sleep deprivation (SD) model to determine the impact of sleep disturbance on iNKT cell biology. After 72 h of SD, C57Bl/6 mice exhibited a significant increase in systemic glucocorticoid levels and thymus atrophy. Despite marked decrease in the number of DP thymocytes, the ratio CD1d⁺/CD1d^- was higher in SD mice, and the number of thymic iNKT cells remained unaltered, suggesting that SD did not compromise the iNKT developmental pathway. In contrast, SD reduced hepatic IFN-γ, but not, IL-4-producing iNKT cells, without further effect in the spleen. Despite this fact, SD did not affect stimulation of IFN-γ production by iNKT cells, or cytokine release, in response to α-galactosylceramide, a specific antigen. Furthermore, although SD impaired splenic NK cells activity against tumor cells, it did not affect iNKT cell-specific cytotoxicity. Thus, our study shows that SD-induced stress did not impair the iNKT cells' responses to a cognate antigen.

Sleep deprivation and its association with diseases- a review

Sleep deprivation, a consequence of multiple health problems or a cause of many major health risks, is a significant public health concern in this era. In the recent years, numerous reports have been added to the literature to provide explanation and to answer previously unanswered questions on this important topic but comprehensive updates and reviews in this aspect remain scarce. The present study identified 135 papers that investigated the association between sleep deprivation and health risks, including cardiovascular, respiratory, neurological, gastrointestinal, immunology, dermatology, endocrine, and reproductive health. In this review, we aimed to provide insight into the association between sleep deprivation and the development of diseases. We reviewed the latest updates available in the literature and particular attention was paid to reports that detailed all possible causal relationships involving both extrinsic and intrinsic factors that may be relevant to this topic. Various mechanisms by which sleep deprivation may affect health were presented and discussed, and this review hopes to serve as a platform for ideas generation for future research.

Evidence for altered insulin receptor signaling in Alzheimer's disease

Epidemiological data have shown that metabolic disease can increase the propensity for developing cognitive decline and dementia, particularly Alzheimer's disease (AD). While this interaction is not completely understood, clinical studies suggest that both hyper- and hypoinsulinemia are associated with an increased risk for developing AD. Indeed, insulin signaling is altered in post-mortem brain tissue from AD patients and treatments known to enhance insulin signaling can improve cognitive function. Further, clinical evidence has shown that AD patients and mouse models of AD often display alterations in peripheral metabolism. Since insulin is primarily derived from the periphery, it is likely that changes in peripheral insulin levels lead to alterations in central nervous system (CNS) insulin signaling and could contribute to cognitive decline and pathogenesis. Developing a better understanding of the relationship between alterations in peripheral metabolism and cognitive function might provide a foundation for the development of better treatment options for patients with AD. In this article we will begin to piece together the present data defining this relationship by briefly discussing insulin signaling in the periphery and CNS, its role in cognitive function, insulin's relationship to AD, peripheral metabolic alterations in mouse models of AD and how information from these models helps understand the mechanisms through which these changes potentially lead to impairments in insulin signaling in the CNS, and potential ways to target insulin signaling that could improve cognitive function in AD. This article is part of the Special Issue entitled 'Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.'