Hepatic macrophage accumulation with aging: cause for concern?

Author(s):  
Steven A. Bloomer ◽  
Eric Moyer

Aging is associated with chronic, low-grade inflammation that adversely affects physiological function. The liver regulates systemic inflammation; it is a source of cytokine production and also scavenges bacteria from the portal circulation to prevent infection of other organs. The cells with primary roles in these functions, hepatic macrophages, become more numerous in the liver with "normal" aging (i.e. in the absence of disease). Here we demonstrate evidence and potential mechanisms for this phenomenon, which include augmented tumor necrosis factor-α (TNFα) and intercellular adhesion molecule-1 (ICAM-1) expression in the liver. Also, we discuss how an age-related impairment in autophagy within macrophages leads to a pro-oxidative state and ensuing production of pro-inflammatory cytokines, particularly interleukin 6 (IL-6). Given that the liver is a rich source of macrophages, we posit that it represents a major source of the elevated systemic IL-6 observed with aging, which is associated with physiological dysfunction. Testing a causal role for liver macrophage production of IL-6 during aging remains a challenge, yet interventions that have targeted macrophages and/or IL-6 have demonstrated promise in treating age-related diseases. These studies have demonstrated an age-related, deleterious reprogramming of macrophage function, which worsens pathology. Therefore, hepatic macrophage accrual is indeed a cause for concern, and therapies that attenuate the aged phenotype of macrophages will likely prove useful in promoting healthy aging.

2018 ◽  
Vol 39 (02) ◽  
pp. 195-202
Author(s):  
Stephanie Böhmert ◽  
Ralf Schubert ◽  
Stephan Fichtlscherer ◽  
Sonja Alesci ◽  
Wolfgang Miesbach

AbstractThe life expectancy of patients with haemophilia has increased and therefore the interest in age-related comorbidities has grown. The aim of this study was to determine whether haemophilia patients have a different endothelial function compared with the general population. A total of 26 patients with severe or moderate haemophilia A or B, 14 controls and 36 patients with coronary artery disease (CAD) were included in this study. Five markers of endothelial dysfunction (MOEDs) were determined. Moreover, the endothelial function was examined using the Itamar Endo-PAT, and the reactive hyperemia index (RHI) was calculated from the results. The MOEDs soluble intercellular adhesion molecule-1 (p = 0.0095) and interleukin-6 (p = 0.010) were significantly higher for patients with haemophilia compared with the control group. The presence of increased adhesion molecule levels and low-grade inflammation is suggestive of a decreased endothelial function. RHI is impaired in CAD patients (1.862), whereas haemophilia patients have an RHI of 1.958 in comparison with 2.112 in controls (p = 0.127). Therefore, laboratory and functional measurements imply a possible higher risk for CAD in haemophilia patients.


Author(s):  
YuShuang Xu ◽  
XiangJie Liu ◽  
XiaoXia Liu ◽  
Di Chen ◽  
MengMeng Wang ◽  
...  

Frailty is a major public issue that affects the physical health and quality of life of older adults, especially as the population ages. Chronic low-grade inflammation has been speculated to accelerate the aging process as well as the development of age-related diseases such as frailty. Intestinal homeostasis plays a crucial role in healthy aging. The interaction between the microbiome and the host regulates the inflammatory response. Emerging evidence indicates that in older adults with frailty, the diversity and composition structure of gut microbiota are altered. Age-associated changes in gut microbiota composition and in their metabolites contribute to increased gut permeability and imbalances in immune function. In this review, we aim to: identify gut microbiota changes in the aging and frail populations; summarize the role of chronic low-grade inflammation in the development of frailty; and outline how gut microbiota may be related to the pathogenesis of frailty, more specifically, in the regulation of gut-derived chronic inflammation. Although additional research is needed, the regulation of gut microbiota may represent a safe, easy, and inexpensive intervention to counteract the chronic inflammation leading to frailty.


Author(s):  
Sri Nitya Reddy Induri ◽  
Payalben Kansara ◽  
Scott C. Thomas ◽  
Fangxi Xu ◽  
Deepak Saxena ◽  
...  

Metformin has been extensively used for the treatment of type 2 diabetes, and it may also promote healthy aging. Despite its widespread use and versatility, metformin's mechanisms of action remain elusive. The gut typically harbors thousands of bacterial species, and as the concentration of metformin is much higher in the gut as compared to plasma, it is plausible that microbiome-drug-host interactions may influence the functions of metformin. Detrimental perturbations in the aging gut microbiome lead to the activation of the innate immune response concomitant with chronic low-grade inflammation. With the effectiveness of metformin in diabetes and antiaging varying among individuals, there is reason to believe that the gut microbiome plays a role in the efficacy of metformin. Metformin has been implicated in the promotion and maintenance of a healthy gut microbiome and reduces many age-related degenerative pathologies. Mechanistic understanding of metformin in the promotion of a healthy gut microbiome and aging will require a systems-level approach. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 62 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2015 ◽  
Vol 114 (11) ◽  
pp. 1819-1828 ◽  
Author(s):  
Karianna F. M. Teunissen-Beekman ◽  
Janneke Dopheide ◽  
Johanna M. Geleijnse ◽  
Stephan J. L. Bakker ◽  
Elizabeth J. Brink ◽  
...  

AbstractEndothelial dysfunction (ED) and low-grade inflammation (LGI) have a role in the development of CVD. The two studies reported here explored the effects of dietary proteins and carbohydrates on markers of ED and LGI in overweight/obese individuals with untreated elevated blood pressure. In the first study, fifty-two participants consumed a protein mix or maltodextrin (3×20 g/d) for 4 weeks. Fasting levels and 12 h postprandial responses of markers of ED (soluble intercellular adhesion molecule 1 (sICAM), soluble vascular cell adhesion molecule 1 (sVCAM), soluble endothelial selectin and von Willebrand factor) and markers of LGI (serum amyloid A, C-reactive protein and sICAM) were evaluated before and after intervention. Biomarkers were also combined into mean Z-scores of ED and LGI. The second study compared 4 h postprandial responses of ED and LGI markers in forty-eight participants after ingestion of 0·6 g/kg pea protein, milk protein and egg-white protein. In addition, postprandial responses after maltodextrin intake were compared with a protein mix and sucrose. The first study showed significantly lower fasting ED Z-scores and sICAM after 4 weeks on the high-protein diet (P≤0·02). The postprandial studies found no clear differences of ED and LGI between test meals. However, postprandial sVCAM decreased more after the protein mix compared with maltodextrin in both studies (P≤0·04). In conclusion, dietary protein is beneficial for fasting ED, but not for fasting LGI, after 4 weeks of supplementation. On the basis of Z-scores, postprandial ED and LGI were not differentially affected by protein sources or carbohydrates.


2007 ◽  
Vol 35 (5) ◽  
pp. 644-656 ◽  
Author(s):  
D Feng ◽  
W Xu ◽  
G Chen ◽  
C Hang ◽  
H Gao ◽  
...  

Traumatic brain injury (TBI) can induce a persistent inflammatory response, histopathological changes and apoptosis in the intestine. Glutamine has been shown to reduce bacterial translocation and maintain intestine mucosal integrity, but its effects on the inflammatory response, structural alterations and apoptosis in intestinal mucosa following TBI have not been previously investigated. Using the weight-drop method, a right parietal cortical contusion was induced in rats and, for the next 5 days, they were fed either chow alone or chow mixed with glutamine. Intestinal tissue samples were then removed for analysis. Following TBI, glutamine supplementation was found to: decrease intestinal concentrations of interleukin (IL) −1β, tumour necrosis factor-α (TNF-α) and IL-6; downregulate intercellular adhesion molecule-1 (ICAM-1) expression; attenuate TBI-induced damage to the intestine structure; and reduce apoptosis. These results suggest that post-TBI glutamine administration could suppress intestinal inflammation, protect intestinal mucosal structure and reduce mucosal apoptosis.


2018 ◽  
Vol 74 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Joanna J. Samulak ◽  
Angelika K. Sawicka ◽  
Dace Hartmane ◽  
Solveiga Grinberga ◽  
Osvalds Pugovics ◽  
...  

Background: L-carnitine can be metabolized to trimethylamine N-oxide (TMAO), a molecule that promotes atherogenesis through its interaction with macrophages and lipid metabolism. Objective: The aim of the present study was to assess whether L-carnitine supplementation may promote changes in selected serum biomarkers of atherosclerosis. Methods: Before the start, in the mid-point and after completing the 24-weeks supplementation protocol, fasting blood samples were taken from the antecubital vein. Plasma free L-carnitine and TMAO were determined by the UPLC/MS/MS method. Serum proteins were determined by the enzyme immunoassay method using commercially available kits. Total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, and triglycerides have been determined using standard automatic analyzer. Results: L-carnitine supplementation elevated fasting plasma carnitine in the mid-point of our study and it remained increased until the end of supplementation period. Moreover, it induced tenfold increase in plasma TMAO concentration but did not affect serum C-reactive protein, interleukin-6, tumour necrosis factor-α, L-selectin, P-selectin, vascular cell adhesion molecule-1, intercellular adhesion molecule-1 or lipid profile markers. Conclusion: We demonstrated that ­although oral L-carnitine supplementation significantly ­increased plasma TMAO concentration, no lipid profile changes or other markers of adverse cardiovascular events were detected in healthy aged women over the period of 24 weeks.


Blood ◽  
2021 ◽  
Author(s):  
Judith S. Hecker ◽  
Luise Hartmann ◽  
Jennifer Rivière ◽  
Michèle Constanze Buck ◽  
Mark van der Garde ◽  
...  

Clonal hematopoiesis (CH) is an age-related condition predisposing to blood cancer and cardiovascular disease (CVD). Murine models demonstrate CH-mediated altered immune function and proinflammation. Low-grade inflammation has been implicated in the pathogenesis of osteoarthritis (OA), the main indication for total hip arthroplasty (THA). THA-derived hip bones serve as a major source of 'healthy' hematopoietic cells in experimental hematology. We prospectively investigated frequency and clinical associations of CH in 200 patients without known hematologic disease undergoing THA. Prevalence of CH was 50%, including 77 patients with CH of indeterminate potential (CHIP, defined as somatic variants with allele frequencies [VAF] ≥2%), and 23 patients harboring CH with lower mutation burden (VAF 1-2%). Most commonly mutated genes were DNMT3A (29.5%), TET2 (15.0%) and ASXL1 (3.5%). CHIP significantly associated with lower hemoglobin, higher mean corpuscular volume, prior/present malignant disease, and CVD. Strikingly, we observed a previously unreported association of CHIP with autoimmune diseases (AID; multivariate adjusted odds ratio, 6.6; 95% confidence interval [1.7, 30]; p=0.0081). These findings underscore the association between CH and inflammatory diseases. Our results have considerable relevance for management of patients with OA and AID or mild anemia, and question use of hip bone-derived cells as 'healthy' experimental controls.


2021 ◽  
Vol 17 ◽  
Author(s):  
Lili Legiawati

: Diabetes mellitus is a metabolic disorder caused by an increase in insulin resistance, a decrease in insulin production, or both of them, resulting in a high level of blood glucose or hyperglycemia. An uncontrolled state of DM may cause complications, namely skin disorder. One or more skin disorders are found amongst 74% of T2DM patients, with the highest percentage is dry skin (47%), followed by infection (10%), diabetic hand (5%), hair loss and diabetic dermopathy (each 4%). In DM, the state of hyperglycemia and production of advanced glycaemic end-products (AGEs) profoundly impact skin changes. In the pathological pathway, AGEs induce oxidative stress and inflammation. Nonetheless, AGEs level is higher in T2DM patients compared to non-T2DM people. This is caused by hyperglycemia and oxidative stress. Binding between AGEs and receptor of AGEs (RAGE) promotes pathway of oxidative stress and inflammation cascade via mitogen-activated protein kinases (MAPK), nuclear factor-k-light-chain-enhancer of activated β cells (NF-kβ), interleukin- 6 (IL-6), tumor necrosis factor-α (TNF-α), expression of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 2 (VCAM-2) pathway which furtherly effectuates DM complication including skin disorders.


Sign in / Sign up

Export Citation Format

Share Document