Long-term glucocorticoid exposure and incident cardiovascular diseases - the Lifelines cohort.

CONTEXT: Long-term glucocorticoid levels in scalp hair (HairGCs), including cortisol and the inactive form cortisone, represent the cumulative systemic exposure to glucocorticoids over months. HairGCs have repeatedly shown associations with cardiometabolic and immune parameters, but longitudinal data are lacking. DESIGN: We investigated 6341 hair samples of participants from the Lifelines cohort study for cortisol and cortisone levels, and associated these to incident cardiovascular diseases (CVD) during 5-7 years of follow-up. We computed the odds ratio (OR) of HairGC levels for incident CVD via logistic regression, adjusting for classical cardiovascular risk factors, and performed a sensitivity analysis in subcohorts of participants <60 years and >= 60 years. Also, we associated HairGC levels to immune parameters (total leukocytes and subtypes). RESULTS: Hair cortisone levels (available in n = 4701) were independently associated with incident CVD (p < 0.001), particularly in younger individuals (multivariate-adjusted OR 4.21, 95% confidence interval (CI) 1.91-9.07 per point increase in 10-log cortisone concentration (pg/mg), p < 0.001). All immune parameters except eosinophils were associated with hair cortisone (all multivariate-adjusted p < 0.05). CONCLUSIONS: In this large, prospective cohort study, we found that long-term cortisone levels, measured in scalp hair, represent a relevant and significant predictor for future cardiovascular diseases in younger individuals. These results highlight glucocorticoid action as possible treatment target for CVD prevention, where hair glucocorticoid measurements could help identify individuals that may benefit from such treatments.

Psychological, behavioural, and physical aspects of caregiver strain in autism-caregivers: a cohort study.

Background: People who give care to autistic individuals (autism-caregivers) experience higher levels of caregiver strain than people who provide care for individuals with other chronic conditions (non-autism-caregivers). This places them at higher risk for psychological, behavioural and physical health concerns. The aim of this study is to delineate psychological, behavioural, and physical aspects of caregiver strain in autism-caregivers compared to non-autism-caregivers. Methods: We included 3354 adult caregivers from the general population in the Netherlands participating in the second assessment (January, 1, 2014-December, 31, 2017) of the Lifelines Cohort. In this cohort study, using multivariable regression adjusted for age, sex, and socioeconomic status, we analysed psychological (anxiety and depression based on a Mini International Neuropsychiatric Interview, and self-reported stress and perceived health), behavioural (questionnaire-assessed physical activity, alcohol use, and smoking), and physical aspects (body mass index, waist circumference, and leukocyte-counts) of caregiver strain in autism-caregivers (n = 722) compared with non-autism-caregivers (n = 2632). Findings: Autism-caregivers reported more stress (OR 3.61, 95% CI 2.60-4.99). Both anxiety (OR 1.85, 95% CI 1.37-2.49) and depressive disorders (OR 1.83, 95% CI 1.17-2.86) were more common in autism-caregivers than in non-autism-caregivers. Perceived health, physical activity, alcohol use, and smoking were not different between autism- and non-autism-caregivers. In autism-caregivers, lymphocyte- and monocyte-counts were lower than in non-autism-caregivers. Interpretation: In this large cohort, autism-caregivers had worse psychological health than non-autism-caregivers. Moreover, autism-caregiving might be associated with an altered immune balance. These findings underline the higher caregiver strain in autism-caregivers compared to other caregivers. This calls for increased support to autism-caregivers. Funding: Lifelines has been funded by the Dutch government.

Altered Functionality of Lipoprotein(a) Impacts on Angiogenesis in Diabetic Retinopathy.

Purpose: Diabetic retinopathy (DR) is a complication of type 2 diabetes mellitus (T2DM). Lipoprotein(a) (Lp(a)) contributes to the progression of DR, but how is unclear. In homeostasis of the retinal microvasculature, myeloid-derived pro-angiogenic cells (PACs) also play a pivotal role, and fail to function properly in diabetic conditions. Here, we explored the putative contribution of Lp(a) from patients with T2DM with/without DR and healthy controls on inflammation and angiogenesis of retinal endothelial cells (RECs), and on PAC differentiation. Subsequently, we compared the lipid composition of Lp(a) from patients to that from healthy controls. Methods: Lp(a)/LDL obtained from patients and healthy controls were added to TNF-alpha-activated RECs. Expression of VCAM-1/ICAM-1 was measured using flowcytometry. Angiogenesis was determined in REC-pericyte co-cultures stimulated by pro-angiogenic growth factors. PAC differentiation from peripheral blood mononuclear cells was determined by measuring expression of PAC markers. The lipoprotein lipid composition was quantified using detailed lipidomics analysis. Results: Lp(a) from patients with DR (DR-Lp(a)) failed to block TNF-alpha-induced expression of VCAM-1/ICAM-1 in REC whereas Lp(a) from healthy controls (healthy control [HC]-Lp(a)) did. DR-Lp(a) increased REC angiogenesis more than HC-Lp(a) did. Lp(a) from patients without DR showed intermediate profiles. HC-Lp(a) reduced the expression of CD16 and CD105 in PAC, but T2DM-Lp(a) did not. Phosphatidylethanolamine content was lower in T2DM-Lp(a) than in HC-Lp(a). Conclusions: DR-Lp(a) does not show the anti-inflammatory capacity seen with HC-Lp(a), but increases REC angiogenesis, and affects PAC differentiation less than HC-Lp(a). These functional differences in Lp(a) in T2DM-related retinopathy are associated with alterations in the lipid composition as compared to healthy conditions.

Improved Physical and Mental Health After a Combined Lifestyle Intervention with Cognitive Behavioural Therapy for Obesity.

Background: Obesity is a multifactorial, chronic, progressive disease associated with decreased health-related quality of life, comorbidities, and increased mortality risk. Lifestyle interventions, focusing on dietetics, physical exercise, and behavioral therapy, are a cornerstone of therapy. Despite this very multidisciplinary treatment approach, the definition of treatment success is often based only on a weight loss of ≥ 5%. However, the heterogeneous nature of obesity may necessitate a more comprehensive approach to assessing treatment effects. Objectives: Here, we describe changes in physiological, psychological, and behavioral health after a multidisciplinary combined lifestyle intervention (CLI). Additionally, we investigated whether these changes were related to weight loss. Methods: This prospective observational longitudinal study comprised 96 adults with obesity (73 women, 81 Caucasian) participating in a CLI at the Obesity Center CGG, Erasmus University Medical Center, Rotterdam, the Netherlands. The 1.5-year intervention comprised multidisciplinary professional guidance towards a healthy diet, increased physical activity, and included cognitive behavioral therapy. Physiological health outcomes, psychological well-being, eating behavior, and physical activity were assessed after ten weeks and 1.5 years and compared to baseline. Results: An average of 5.2% weight loss (-6.0 kg) was accompanied by a mean 9.8% decrease in fat mass (-5.9 kg; both P < 0.001) and significant improvements in metabolism, hormonal status, and immune parameters (all P < 0.05). Moreover, we observed decreased psychopathology, increased quality of life, and decreased disordered eating (all P < 0.05). Weight loss correlated with most metabolic changes (all P < 0.05) but not with most psychological/behavioral changes. Conclusions: Combined lifestyle intervention in patients with obesity was accompanied by significant improvements in body weight and body composition along with cardiometabolic, endocrine, immunological, psychological, and behavioral improvements. Interestingly, most changes in psychological and behavioral health occurred independently of weight loss. Obesity treatment success should be evaluated based on a combination of physical and patient-reported outcomes rather than weight loss alone.

Monocyte adaptations in patients with obesity during a 1.5 year lifestyle intervention.

Background: Obesity is associated with chronic, low-grade inflammation, which is reflected in altered peripheral blood monocyte characteristics. The aim of this study was to analyze the monocyte subset composition (classical (CM), intermediate (IM) and non-classical monocytes (NCM)), and their inflammatory marker profile (CD14, CD16, CD36, CD45, CD64, CD300e, HLA-DR) in individuals with obesity during a 1.5 year combined lifestyle intervention (CLI), comprising healthy nutrition, increased exercise and behavioral changes. Methods: We analyzed monocyte subset counts and immunophenotypes in 73 individuals with obesity, and associated these to baseline body mass index (BMI) and waist circumference (WC). The measurements were repeated after 10 weeks and at the end of the intervention (1.5 years). Results: Generally, monocyte subset counts were not associated to BMI or WC at baseline, neither did monocyte counts change during the 1.5 year CLI. Immunophenotypically, higher baseline BMI and WC were associated to lower CD14 and higher CD300e expression by all subsets. During CLI there were remarkable changes in marker profiles: expression of CD14, CD36, CD45 and CD64 significantly decreased in CM and IM, as did CD16 (IM and NCM) (p<0.05). CD300e initially decreased after 10 weeks, but increased sharply at 1.5 years (all subsets). We observed no consistent associations between changes in monocyte characteristics and anthropometric changes. Conclusion: A 1.5 year CLI in individuals with obesity mediates persistent immunophenotypic adaptations related to cellular activation in blood monocytes, whereas changes in subset distribution are limited. Lifestyle-induced changes in the inflammatory profile of monocytes differ from the 'less-severe-obesity'-phenotype, suggesting a novel, 'post-weight-loss' monocyte setpoint.

Monocyte response after colorectal surgery: A prospective cohort study.

Background: Tumor resection is the common approach in patients with colorectal malignancy. Profound insight into inflammatory changes that accompany the normal post-operative stress response will establish reference parameters useful for identification of putative complications. Alterations in circulating monocytes might be indicative as these cells are considered to be the most responsive leukocytes to trauma. Therefore, the aim of this study is to assess the monocyte subset kinetic and phenotypic changes in response to surgery. Methods: Fifty patients undergoing colorectal tumor resection were included in a multicenter prospective cohort study. Blood samples were collected early in the morning prior to surgery and the next days through postoperative day three for flowcytometric analysis. Leukocyte subtypes were identified and expression of activation stage-related markers by monocyte subsets was quantified. Results: Changes in leukocyte subset composition and monocyte subset phenotypes were most prominent at the first day postoperatively, after which these parameters typically returned to normal or near-normal preoperative values. The immunophenotypic alterations after surgery were most notable in classical and intermediate monocytes. These included up-regulation of activation markers CD64 and CD62L, but down-regulation of HLA-DR and CD54. Markers of de-activation, CD163 and CD206, were consistently increasingly expressed. Discussion/conclusion: The current study gives detailed insight into the peripheral blood leukocyte response after colorectal cancer surgery. This form of short-term stress induces a rapid and significant redistribution of immune cells. Immunophenotypic alterations in monocytes as a response to surgery suggest a mixed profile of cellular activation and de-activation.

Systemic Listeria monocytogenes infection in aged mice induces long-term neuroinflammation: the role of miR-155.

BACKGROUND: Understanding mechanisms of pathologic neuroinflammation is essential for improving outcomes after central nervous system infections. Brain tissue-resident memory T cells (bTRM) are recruited during central nervous system infection and promote pathogen control as well as noxious inflammation. Our prior studies in young mice showed optimal recruitment of CD8+ bTRM during neuroinvasive Listeria monocytogenes (Lm) infection required miR-155, and was significantly inhibited by anti-miR-155 oligonucleotides. Since Lm is an important pathogen in the elderly, we hypothesized anti-miR-155 would also inhibit accumulation of CD8+ bTRM in aged mice infected with Lm. METHODS: Young (2 mo) and aged (> 18 mo) male C57BL/6 mice were infected intra-peritoneally with wild-type Lm, or avirulent Lm mutants lacking the genes required for intracellular motility (ΔactA) or phagosomal escape (Δhly), then were given antibiotics. Brain leukocytes and their intracellular cytokine production were quantified by flow cytometry >28d post-infection (p.i.). The role of miR-155 was tested by injecting mice with anti-miR-155 or control oligonucleotides along with antibiotics. RESULTS: Aged mice had significantly more homeostatic CD8+ bTRM than did young mice, which did not increase after infection with wild-type Lm despite 50% mortality, whereas young mice suffered no mortality after a larger inoculum. For direct comparison of post-infectious neuroinflammation after the same inoculum, young and aged mice were infected with 107 CFU ΔactA Lm. This mutant caused no mortality and significantly increased CD8+ bTRM 28d p.i. in both groups, whereas bone marrow-derived myeloid cells, particularly neutrophils, increased only in aged mice. Notably, anti-miR-155 reduced accumulation of brain myeloid cells in aged mice after infection, whereas CD8+ bTRM were unaffected. CONCLUSIONS: Systemic infection with Lm ΔactA is a novel model for studying infection-induced brain inflammation in aged mice without excessive mortality. CD8+ bTRM increase in both young and aged mice after infection, whereas only in aged mice bone marrow-derived myeloid cells increase long-term. In aged mice, anti-miR-155 inhibits brain accumulation of myeloid cells, but not CD8+ bTRM. These results suggest young and aged mice differ in manifestations and mechanisms of infection-induced neuroinflammation and give insight for developing therapies to ameliorate brain inflammation following severe infection in the elderly.

Intra-articular injection of triamcinolone acetonide sustains macrophage levels and aggravates osteophytosis during degenerative joint disease in mice.

BACKGROUND AND PURPOSE: Corticosteroids such as triamcinolone acetonide (TAA) are potent drugs administered intra-articularly as an anti-inflammatory therapy to relieve pain associated with osteoarthritis (OA). However, the ability of early TAA intervention to mitigate OA progression and modulate immune cell subsets remains unclear. Here, we sought to understand the effect of early intra-articular injection of TAA on OA progression, local macrophages, and peripheral blood monocytes. EXPERIMENTAL APPROACH: Degenerative joint disease was induced by intra-articular injection of collagenase into the knee joint of male C57BL/6 mice. After 1 week, TAA or saline was injected intra-articularly. Blood was taken throughout the study to analyse monocyte subsets. Mice were killed at days 14 and 56 post-induction of collagenase-induced OA (CiOA) to examine synovial macrophages and structural OA features. KEY RESULTS: The percentage of macrophages relative to total live cells present within knee joints was increased in collagenase- compared with saline-injected knees at day 14 and was not altered by TAA treatment. However, at day 56, post-induction of CiOA, TAA-treated knees had increased levels of macrophages compared with the knees of untreated CiOA-mice. The distribution of monocyte subsets present in peripheral blood was not altered by TAA treatment during the development of CiOA. Osteophyte maturation was increased in TAA-injected knees at day 56. CONCLUSION AND IMPLICATIONS: Intra-articular injection of TAA increases long-term synovial macrophage numbers and osteophytosis. Our findings suggest that TAA accentuates the progression of osteoarthritis-associated features when applied to an acutely inflamed knee.

Hair cortisol, obesity and the immune system: Results from a 3 year longitudinal study.

OBJECTIVES: Higher long-term glucocorticoid levels, measured in scalp hair (HairGC), are associated with obesity. This may represent the state of obesity (perhaps interrelated with chronic immune activation), but could also promote further weight gain. We studied whether hair cortisol (HairF) and hair cortisone (HairE) predict changes in body mass index (BMI) and waist circumference (WC) over time, and assessed the association between HairGC and common immune parameters. METHODS: We measured HairGC in 1604 participants of the Netherlands Study of Depression and Anxiety (NESDA), and investigated their associations to BMI, WC, and immune parameters (interleukin-6 (IL-6), C-reactive protein (CRP), and leukocyte subsets). Also, we assessed whether baseline HairGC predict changes in BMI and WC at follow-up (three years later). RESULTS: In cross-sectional analyses, HairF and HairE were positively associated to BMI (ß = 2.06 kg/m2, 95% confidence interval (CI)= 1.22-2.90 kg/m2) and ß = 2.84 kg/m2 (95%CI 1.75-3.93 kg/m2) respectively) and WC (ß = 5.36 cm (95%CI 3.09-7.62 cm) and ß = 8.54 cm (95%CI 5.60-11.48 cm) respectively, all p < 0.001). HairF was also positively associated to IL-6 (ß = 0.15 (95%CI 0.003-0.292) p < 0.05) and leukocyte count (ß = 0.57 (95%CI 0.234-0.909), p < 0.01), and HairE to IL-6 (ß = 0.21 (95%CI 0.016-0.399), p < 0.05). In the longitudinal analyses, higher HairF was associated with yearly increases in BMI (ß = 0.58% BMI change per year (95%CI 0.14-1.01%), p = 0.009) and higher HairE with increases in WC (ß = 0.84% WC change per year (95%CI 0.02-1.69%), p = 0.049). Adjusting for baseline IL-6 or leukocytes did not change the found associations between HairGC and WC or BMI change. CONCLUSIONS: HairGC levels are positively associated to BMI, WC, IL-6 and leukocyte numbers in cross-sectional analyses, and to increases in BMI and WC in longitudinal analyses. Although causality is yet to be proven, higher long-term glucocorticoid levels could represent a relevant risk factor for the development of obesity.

Brown Seaweed Food Supplementation: Effects on Allergy and Inflammation and Its Consequences.

Multiple health benefits have been ascribed to brown seaweeds that are used traditionally as dietary component mostly in Asia. This systematic review summarizes information on the impact of brown seaweeds or components on inflammation, and inflammation-related pathologies, such as allergies, diabetes mellitus and obesity. We focus on oral supplementation thus intending the use of brown seaweeds as food additives. Despite the great diversity of experimental systems in which distinct species and compounds were tested for their effects on inflammation and immunity, a remarkably homogeneous picture arises. The predominant effects of consumption of brown seaweeds or compounds can be classified into three categories: (1) inhibition of reactive oxygen species, known to be important drivers of inflammation; (2) regulation, i.e., in most cases inhibition of proinflammatory NF-κB signaling; (3) modulation of adaptive immune responses, in particular by interfering with T-helper cell polarization. Over the last decades, several inflammation-related diseases have increased substantially. These include allergies and autoimmune diseases as well as morbidities associated with lifestyle and aging. In this light, further development of brown seaweeds and seaweed compounds as functional foods and nutriceuticals might contribute to combat these challenges.

IL-23 receptor deficiency results in lower bone mass via indirect regulation of bone formation.

The IL-23 receptor (IL-23R) signaling pathway has pleiotropic effects on the differentiation of osteoclasts and osteoblasts, since it can inhibit or stimulate these processes via different pathways. However, the potential role of this pathway in the regulation of bone homeostasis remains elusive. Therefore, we studied the role of IL-23R signaling in physiological bone remodeling using IL-23R deficient mice. Using µCT, we demonstrate that 7-week-old IL-23R-/- mice have similar bone mass as age matched littermate control mice. In contrast, 12-week-old IL-23R-/- mice have significantly lower trabecular and cortical bone mass, shorter femurs and more fragile bones. At the age of 26 weeks, there were no differences in trabecular bone mass and femur length, but most of cortical bone mass parameters remain significantly lower in IL-23R-/- mice. In vitro osteoclast differentiation and resorption capacity of 7- and 12-week-old IL-23R-/- mice are similar to WT. However, serum levels of the bone formation marker, PINP, are significantly lower in 12-week-old IL-23R-/- mice, but similar to WT at 7 and 26 weeks. Interestingly, Il23r gene expression was not detected in in vitro cultured osteoblasts, suggesting an indirect effect of IL-23R. In conclusion, IL-23R deficiency results in temporal and long-term changes in bone growth via regulation of bone formation.

Keep your macrophages fit for healthy aging.

As age is the greatest risk factor for the development of most prevalent chronic diseases, there is an enormous interest in understanding the process of aging, with the hope of delaying or preventing age-related comorbidities. Along these lines, a recent study by Minhas et al. (2021) describes how aged macrophages downregulate glycolysis and mitochondrial oxidative phosphorylation (OXPHOS), inducing an energy-deficient state that compromises macrophage function and supports maladaptive inflammation that together cause brain dysfunction.

Macrophage phenotypes and monocyte subsets after destabilization of the medial meniscus in mice.

Macrophages play an important role in the development and progression of osteoarthritis (OA). The aim of this study was to identify macrophage phenotypes in synovium and monocyte subsets in peripheral blood in C57BL/6 mice by destabilizing the medial meniscus (DMM), and the association of macrophage subsets with OA features. DMM, sham, and non-operated knees were histologically assessed between 1 and 56 days for macrophage polarization states by immunohistochemistry (IHC), cartilage damage, synovial thickening, and osteophytes (n = 9 per timepoint). Naive knees (n = 6) were used as controls. Monocyte and polarized synovial macrophage subsets were evaluated by flow cytometry. CD64 and CD206 levels on IHC were higher at early timepoints in DMM and sham knees compared to naive knees. iNOS labeling intensity was higher in DMM and sham knees than in naive knees from d3 onwards. CD163 expression was unaltered at all timepoints. Even though macrophage polarization profiles were similar in DMM and sham knees, only in DMM knees the presence of iNOS and CD206 associated with synovial thickness, and CD163 staining inversely correlated with osteophyte presence. At day 14, monocyte subset distribution was different in peripheral blood of DMM mice compared with sham mice. In conclusion, monocyte subsets in blood and synovial macrophage phenotypes vary after joint surgery. High levels of iNOS+ , CD163+ , and CD206+ cells are found in both destabilized and sham-operated knees, and coexistence with joint instability may be a requirement to initiate and exacerbate OA progression.

Classic and new mediators for in vitro modelling of human macrophages.

Macrophages are key immune cells in the activation and regulation of immune responses. These cells are present in all tissues under homeostatic conditions and in many disease settings. Macrophages can exhibit a wide range of phenotypes depending on local and systemic cues that drive the differentiation and activation process. Macrophage heterogeneity is also defined by their ontogeny. Tissue macrophages can either derive from circulating blood monocytes or are seeded as tissue-resident macrophages during embryonic development. In humans, the study of in vivo-generated macrophages is often difficult with laborious and cell-changing isolation procedures. Therefore, translatable, reproducible, and robust in vitro models for human macrophages in health and disease are necessary. Most of the methods for studying monocyte-derived macrophages are based on the use of limited factors to differentiate the monocytes into macrophages. Current knowledge shows that the in vivo situation is more complex, and a wide range of molecules in the tissue microenvironment promote and impact on monocyte to macrophage differentiation as well as activation. In this review, macrophage heterogeneity is discussed and the human in vitro models that can be applied for research, especially for monocyte-derived macrophages. We also focus on new molecules (IL-34, platelet factor 4, etc.) used to generate macrophages expressing different phenotypes.

The Impact of Obesity and Lifestyle on the Immune System and Susceptibility to Infections Such as COVID-19.

Background: COVID-19 is a global challenge to healthcare. Obesity is common in patients with COVID-19 and seems to aggravate disease prognosis. In this review we explore the link between obesity, chronic disease, lifestyle factors and the immune system, and propose societal interventions to enhance global immunity. Search Strategy and Selection Criteria: We performed three literature searches using the keywords (1) coronavirus AND comorbidities, (2) comorbidities AND immune system, and (3) lifestyle factors AND immune system. Results were screened for relevance by the main author and a total of 215 articles were thoroughly analyzed. Results: The relationship between obesity and unfavorable COVID-19 prognosis is discussed in light of the impact of chronic disease and lifestyle on the immune system. Several modifiable lifestyle factors render us susceptible to viral infections. In this context, we make a case for fostering a healthy lifestyle on a global scale. Conclusions: Obesity, additional chronic disease and an unhealthy lifestyle interactively impair immune function and increase the risk of severe infectious disease. In adverse metabolic and endocrine conditions, the immune system is geared toward inflammation. Collective effort is needed to ameliorate modifiable risk factors for obesity and chronic disease on a global scale and increase resistance to viruses like SARS-CoV-2.

Mycobacterium tuberculosis clinical isolates of the Beijing and East-African Indian lineage induce fundamentally different host responses in mice compared to H37Rv.

Substantial differences exist in virulence among Mycobacterium tuberculosis strains in preclinical TB models. In this study we show how virulence affects host responses in mice during the first four weeks of infection with a mycobacterial strain belonging to the Beijing, East-African-Indian or Euro-American lineage. BALB/c mice were infected with clinical isolates of the Beijing-1585 strain or the East-African Indian (EAI)-1627 strain and host responses were compared to mice infected with the non-clinical H37Rv strain of the Euro-American lineage. We found that H37Rv induced a 'classical' T-cell influx with high IFN-γ levels, while Beijing-1585 and EAI-1627 induced an influx of B-cells into the lungs together with elevated pulmonary IL-4 protein levels. Myeloid cells in the lungs appeared functionally impaired upon infection with Beijing-1585 and EAI-1627 with reduced iNOS and IL-12 expression levels compared to H37Rv infection. This impairment might be related to significantly reduced expression in the bone marrow of IFN-γ, TNF-α and IFN-ß in mice infected with Beijing-1585 and EAI-1627, which could be detected from the third day post infection onwards. Our findings suggest that increased virulence of two clinical isolates compared to H37Rv is associated with a fundamentally different systemic immune response, which already can be detected early during infection.

Metabolic Alterations in Aging Macrophages: Ingredients for Inflammaging?

Aging is a complex process with an impact on essentially all organs. Declined cellular repair causes increased damage at genomic and proteomic levels upon aging. This can lead to systemic changes in metabolism and pro-inflammatory cytokine production, resulting in low-grade inflammation, or 'inflammaging'. Tissue macrophages, gatekeepers of parenchymal homeostasis and integrity, are prime inflammatory cytokine producers, as well as initiators and regulators of inflammation. In this opinion piece, we summarize intrinsic alterations in macrophage phenotype and function with age. We propose that alternatively activated macrophages (M2-like), which are yet pro-inflammatory, can accumulate in tissues and promote inflammaging. Age-related increases in endoplasmic reticulum stress and mitochondrial dysfunction might be cell-intrinsic forces driving this unusual phenotype.

Comparative proteomic analysis of cat eye syndrome critical region protein 1- function in tumor-associated macrophages and immune response regulation of glial tumors.

INTRODUCTION: Tumor associated macrophages (TAMs) promote tumor development, angiogenesis and distal metastasis. In previous studies, we showed that Cat Eye Syndrome Critical Region Protein 1 (CECR1) is expressed by M2-like TAMs in human glioma samples. CECR1 promoted M2 TAMs differentiation and affected glioma cell proliferation and migration. Here we investigated the proteomic profile of TAMs expressing CECR1 in absence or presence of glioma cells. RESULTS: CECR1 siRNA transfection upregulated 67 proteins in THP-1-derived Macrophages (MQs). Pathway annotation mapped this set to 3 major pathways relevant for MQ function, including 'MHC-I antigen presentation', 'phagosome maturation' and 'endocytosis'. Co-culture of siCECR1 THP-1-derived MQs with U87 glioma cells attenuated the changes observed on protein and mRNA level in response to MQ CECR1 silencing. SiCECR1 in U87 co-cultured MQs was associated with an IL-10low, IL-12high M1-like phenotype. In U87 co-culture conditions, SiCECR1 also downregulated S20 proteasome complex proteins PSMA5, PSMA7, PSMC6 and PSMD8. This protein profile was linked to a low proliferation rate of siCECR1 MQs. Overlap analysis identified S100A9 and PLAU as CECR1-related proteins that were significantly correlated with expression of CECR1 and macrophage lineage markers in three large public GBM datasets. CONCLUSION: This study reports the molecular pathways and key molecules that are mediated by CECR1 function in THP- 1-derived MQs and TAMs in glioma. METHODS: PMA-treated THP-1 cells (MQs) were siRNA transfected for CECR1 in vitro, with or without stimulation of the primary glioma cell line U87. Lysates were analyzed by (nano)LC-MS. Significant altered protein levels were identified (P < 0.05), followed by pathway annotation.

Three-dimensional tubule formation assay as therapeutic screening model for ocular microvascular disorders.

PURPOSE: This study is aimed to adapt a three-dimensional (3-D) in vitro angiogenesis model to the ophthalmology field using retinal endothelial cells (REC). This system is applied to assess the angiogenic capacity of aqueous humor (AH) from patients with ocular disorders, and to test the effect of VEGF inhibitor (aflibercept) on induced angiogenesis. METHODS: Human REC and umbilical vein endothelial cells (HUVEC) and pericytes were co-cultured in a gel matrix with 25-200 ng/ml pro-angiogenic growth factors (GF). AH from patients with cataract, glaucoma or proliferative diabetic retinopathy (PDR) was tested in the REC-pericyte co-culture. Aflibercept was then introduced to the co-culture containing PDR AH. The surface area and total tubule length were measured using Image J. RESULTS: Optimal GF concentrations at 200 ng/ml induced angiogenesis by REC as well as HUVEC, while vessel formation by both cell types was strongly reduced using 25-50 ng/ml GF. Addition of AH from the PDR patient triggered tubule formation by REC at low GF concentration. Aflibercept, however, significantly inhibited angiogenesis induced by PDR AH, but showed no significant influence on other conditions. CONCLUSION: REC can be applied efficiently in the 3-D in vitro angiogenesis model as a diagnostic tool to assess the AH angiogenic status and to validate new anti-angiogenic therapeutic compounds prior to clinical trial.

Regulation of Intracellular Triiodothyronine Is Essential for Optimal Macrophage Function.

Innate immune cells, including macrophages, have recently been identified as target cells for thyroid hormone. We hypothesized that optimal intracellular concentrations of the active thyroid hormone triiodothyronine (T3) are essential for proinflammatory macrophage function. T3 is generated intracellularly by type 2 deiodinase (D2) and acts via the nuclear thyroid hormone receptor (TR). In zebrafish embryos, D2 knockdown increased mortality during pneumococcal meningitis. Primary murine D2 knockout macrophages exhibited impaired phagocytosis and partially reduced cytokine response to stimulation with bacterial endotoxin. These effects are presumably due to reduced intracellular T3 availability. Knockdown of the main TR in macrophages, TRα, impaired polarization into proinflammatory macrophages and amplified polarization into immunomodulatory macrophages. Intracellular T3 availability and action appear to play a crucial role in macrophage function. Our data suggest that low intracellular T3 action has an anti-inflammatory effect, possibly due to an effect on macrophage polarization mediated via the TRα. This study provides important insights into the link between the endocrine and innate immune system.