Adiponectin suppression of late inflammatory mediator, HMGB1-induced cytokine expression in RAW264 macrophage cells

Causal association between adiponectin and risk of trigeminal neuralgia: A Mendelian randomization study

OBJECTIVE

To determine whether adiponectin levels and the risk of trigeminal neuralgia (TN) were causally related, a two-sample Mendelian Randomization (MR) study design was used.

METHODS

We obtained data regarding adiponectin from the UK Biobank genome wide association studies (GWAS) (n = 39,883) as the exposure and TN, using GWAS summary statistics generated from FinnGen, (total n = 195 847 159; case = 800, control = 195 047) as the outcome. We conducted a two-sample Mendelian randomization analysis employing inverse variance-weighted (IVW), MR-Egger regression, weighted median, and weighted mode analyses.

RESULTS

We selected 14 single nucleotide polymorphisms (SNPs) with genome-wide significance from the GWAS on adiponectin as instrumental variables. Based on the IVW method, a causal association between adiponectin levels and TN was evidenced (OR= 0.577, 95 %CI: 0.393-0.847). MR-Egger regression revealed that directional pleiotropy was unlikely to be biasing the result (intercept = -0.01; P = 0.663), but it showed no causal association between adiponectin and TN (OR=0.627, 95 %CI: 0.369-1.067). However, the weighted median (OR=0.569, 95 %CI: 0.353-0.917) and Weighted mode (OR= 0.586, 95 %CI: 0.376-0.916) approach yielded evidence of a causal association between adiponectin and TN. Cochran's Q-statistics and funnel plots indicated no evidence of heterogeneity or asymmetry, indicating no directional pleiotropy.

CONCLUSION

The results of the MR analysis suggested that adiponectin may be causally associated with an increased TN risk.

Adiponectin Ameliorates Hyperglycemia-Induced Retinal Endothelial Dysfunction, Highlighting Pathways, Regulators, and Networks

Background

The pathophysiology of diabetic retinopathy (DR) is multifaced. A low level of circulating adiponectin (APN) in type 2 diabetes is associated with microvasculature complications, and its role in the evolution of DR is complex.

Aim

This study is designed to explore the potential impact of APN in the pathogenesis of DR, linking the changes in cellular and biological processes with the pathways, networks, and regulators involved in its actions.

Methods

Human microvascular retinal endothelial cells (HMRECs) were exposed to 30mM glucose (HG) and treated with globular adiponectin (30μg/mL) for 24 hours. The cells were evaluated for reactive oxidative stress (ROS) and apoptosis. RT-PCR profile arrays were utilized to evaluate the profile of genes involved in endothelial functions, angiogenesis, extracellular matrix, and adhesion molecules for hyperglycemic HMRECs treated with adiponectin. In addition, the barrier function, leukocyte migration, and angiogenesis were evaluated. The differential expressed genes (DEGs) were outlined, and bioinformatic analysis was applied.

Results

Adiponectin suppresses ROS production and apoptosis in HMRECs under HG conditions. Adiponectin improved migration and barrier functions in hyperglycemic cells. The bioinformatic analysis highlighted that the signaling pathways of integrin, HMGB1, and p38 AMPK, are mainly involved in the actions of APN on HMRECs. APN significantly affects molecular functions, including the adhesion of cells, chemotaxis, migration of WBCs, and angiogenesis. STAT3, NFKB, IKBKB, and mir-8 are the top upstream regulators, which affect the expressions of the genes of the data set, while TNF and TGFB1 are the top regulators.

Conclusion

Adiponectin significantly counteracts hyperglycemia at various cellular and molecular levels, reducing its impact on the pathophysiological progression towards DR in vitro using HMRECs. Adiponectin ameliorates inflammatory response, oxidative stress, and endothelial barrier dysfunction using a causal network of NFBk complex, TNF, and HMGB1 and integrin pathways.

Nanocurcumin alleviates inflammation and oxidative stress in LPS-induced mastitis via activation of Nrf2 and suppressing TLR4-mediated NF-κB and HMGB1 signaling pathways in rats

Coliform mastitis is a worldwide serious disease of the mammary gland. Curcumin is a pleiotropic polyphenol obtained from turmeric, but it is hydrophobic and rapidly eliminated from the body. However, nanoformulation of curcumin significantly improves its pharmacological activity by enhancing its hydrophobicity and oral bioavailability. Our study aimed to investigate the possible antioxidant and anti-inflammatory effects of nanocurcumin as a prophylactic against LPS-induced coliform mastitis in rat model, where LPS was extracted from a field strain of Escherichia coli (bovine mastitis isolate). The study was conducted on twenty lactating Wistar female rats divided into four equal groups, and the mastitis model was initiated by injection of LPS through the duct of the mammary gland. The results showed that nanocurcumin significantly attenuated the lipid peroxidation (MDA), oxidized glutathione, the release of pro-inflammatory cytokines (TNF-α and IL-1β), and the gene expression of TLR4, NF-κB p65, and HMGB1. Meanwhile, it improved the reduced glutathione level and Nrf2 activity and preserved the normal alveolar architecture. These findings suggested that nanocurcumin supplementation can be a promising potential protective approach for coliform mastitis.

Understanding the Psychological, Physiological, and Genetic Factors Affecting Precision Pain Medicine: A Narrative Review

PURPOSE

Precision pain medicine focuses on employing methods to assess each patient individually, identify their risk profile for disproportionate pain and/or the development of chronic pain, and optimize therapeutic strategies to target specific pathological processes underlying chronic pain. This review aims to provide a concise summary of the current body of knowledge regarding psychological, physiological, and genetic determinants of chronic pain related to precision pain medicine.

METHODS

Following the Scale for the Assessment of Narrative Review Articles (SANRA) criteria, we employed PubMed/Medline to identify relevant articles using primary database search terms to query articles such as: precision medicine, non-modifiable factors, pain, anesthesiology, quantitative sensory testing, genetics, pain medicine, and psychological.

RESULTS

Precision pain medicine provides an opportunity to identify populations at risk, develop personalized treatment strategies, and reduce side effects and cost through elimination of ineffective treatment strategies. As in other complex chronic health conditions, there are two broad categories that contribute to chronic pain risk: modifiable and non-modifiable patient factors. This review focuses on three primary determinants of health, representing both modifiable and non-modifiable factors, that may contribute to a patient's profile for risk of developing pain and most effective management strategies: psychological, physiological, and genetic factors.

CONCLUSION

Consideration of these three domains is already being integrated into patient care in other specialties, but by understanding the role they play in development and maintenance of chronic pain, we can begin to implement both precision and personalized treatment regimens.

Secondary data analysis investigating effects of marine omega-3 fatty acids on circulating levels of leptin and adiponectin in older adults

BACKGROUND

Higher leptin and lower adiponectin levels have been linked to progressing systemic inflammation and diseases of aging. Among older adults with obesity and an inflammatory conditions, we quantified effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation on leptin, adiponectin, and the leptin-to-adiponectin ratio (LAR). We also examined associations among adipokine and cytokine levels.

METHODS

Using a randomized, double-blind, placebo-controlled design, participants (mean age 61.3 ± 2.1) received 1.5 g EPA + 1.0 g DHA (n = 14) or mineral oil (n = 18) daily. Plasma adipokine and cytokine levels were quantified by electrochemiluminescence at all study intervals.

RESULTS

While no between-group differences were detected, there was a reduction in the LAR (by 23%, p=.065) between weeks 4 and 8 among the EPA+DHA group. Adiponectin levels were negatively associated with IL-1β levels at week 4 (p=.02) and TNF-α levels at week 8 (p=.03).

CONCLUSION

Potential benefits of EPA+DHA supplementation among aging populations warrant further study.

Ethyl Pyruvate Alleviates Pulmonary Hypertension through the Suppression of Pulmonary Artery Smooth Muscle Cell Proliferation via the High Mobility Group Protein B1/Receptor for Advanced Glycation End-Products Axis

Purpose: Pulmonary arterial hypertension (PAH) is a formidable disease with no effective treatment at present. With the goal of developing potential therapies, we attempted to determine whether ethyl pyruvate (EP) could alleviate PAH and its mechanism.

Methods: Pulmonary smooth muscle cells were cultured in conventional low-oxygen environments, and cellular proliferation was monitored after treatment with either EP or phosphate-balanced solution (PBS). Expression of high mobility group protein B1 (HMGB1) and receptor for advanced glycation end-products (RAGE) protein were detected by western blot. After hyperkinetic PAH rat models were treated with EP, hemodynamic data were collected. Right ventricular hypertrophy and pulmonary vascular remodeling were evaluated. Expression of HMGB1 and RAGE protein was also detected.

Results: In vitro, proliferative activity increased in low-oxygen environments, but was inhibited by EP treatment. Furthermore, Western blotting showed the decreased expression of HMGB1 and RAGE protein after EP treatment. In vivo, pulmonary artery pressures were attenuated with EP. Right ventricular hypertrophy and pulmonary vascular remodeling were also reversed. Additionally, the expression levels of HMGB1 and RAGE were reduced in lung tissues.

Conclusions: EP can alleviate PAH by suppressing the proliferation of pulmonary artery smooth muscle cells via inhibition of HMGB1/RAGE expression.

Lactoferrin suppresses LPS-induced expression of HMGB1, microRNA 155, 146, and TLR4/MyD88/NF-кB pathway in RAW264.7 cells

OBJECTIVE

This current study evaluated the underlying mechanisms of LF against the inflammatory microRNAs (miRNAs), HMGB1 expression, and TLR4-MyD88-NF-кB pathway in LPS-activated murine RAW264.7 cells.

METHODS

MTT assay was used to assess cell metabolism and the cell culture levels of the cytokines (TNF-α, IL-6) were evaluated by Enzyme-linked immunosorbent assay (ELISA). The expression of miRNAs was quantified by using qPCR and the expression of HMGB1, TLR4, MyD88, and phosphorylated NF-κB (P-p65) were determined with Western blot and qPCR, respectively.

RESULTS

The results indicated that LF downregulates IL-6 and TNF-α expression. LF exhibited the degradation of P-p65 and reduced the production of HMGB1, TLR4, and MyD88 in LPS-induced inflammatory response. Importantly, in parallel with the suppression of cytokines and HMGB1-TLR4-MyD88-NF-кB pathway, LF could induce a decrease in inflammatory selected miRNAs, mmu-mir-155, and mmu-mir-146a expression.

CONCLUSIONS

Altogether, these findings provide LF as a prominent anti-inflammatory agent that could modulate HMGB1, mmu-mir-155, mmu-mir-146a, and TLR4/MyD88/NF-кB pathway.

Downregulation of Lysosomal Acid Ceramidase Mediates HMGB1-Induced Migration and Proliferation of Mouse Coronary Arterial Myocytes

High-mobility group box 1 protein (HMGB1) has been reported to trigger lysosome destabilization causing a wide of inflammatory diseases. The present study tested whether a lysosomal enzyme, acid ceramidase (AC), plays a critical role in HMGB1-induced alteration in ceramide metabolism and whether such HMGB1-AC interaction is associated with abnormal migration and proliferation of vascular smooth muscle cells (SMCs). We first observed that the expression of AC in the medial layer of mouse coronary arterial wall and colocalization of AC with a lysosome marker Lamp-1. In primary cultured coronary arterial myocytes (CAMs), AC expression and colocalization with Lamp-1 were significantly up-regulated by AC inducer, genistein, but down-regulated by AC inhibitor, N-oleoylethanolamine (NOE). HMGB1 dose-dependently decreased the colocalization of AC with Lamp-1 and reduced mRNA and protein expressions of AC in CAMs, but reversed by genistein. Consistently, HMGB1 significantly induced increases in the levels of long-chain ceramides in CAMs, which were not further enhanced by NOE but blocked by genistein. More importantly, HMGB1 promoted migration and proliferation of CAMs, which were not further increased by NOE but reduced by genistein. Lastly, CAMs isolated from smooth muscle-specific AC knockout mice (AC gene Asah1) exhibited increased ceramide levels and enhanced the migration and proliferation, which resembles the effects of HMGB1 on wild-type CAMs. Together, these results suggest that HMGB1 promotes SMC migration and proliferation via inhibition of AC expression and ceramide accumulation.

The Role of Leptin and Adiponectin in Obesity-Associated Cognitive Decline and Alzheimer's Disease

Cross-talk between adipose tissue and central nervous system (CNS) underlies the increased risk of obese people to develop brain diseases such as cognitive and mood disorders. Detailed mechanisms for how peripheral changes caused by adipose tissue accumulation in obesity impact the CNS to cause brain dysfunction are poorly understood. Adipokines are a large group of substances secreted by the white adipose tissue to regulate a wide range of homeostatic processes including, but not limited to, energy metabolism and immunity. Obesity is characterized by a generalized change in the levels of circulating adipokines due to abnormal accumulation and dysfunction of adipose tissue. Altered adipokine levels underlie complications of obesity as well as the increased risk for the development of obesity-related comorbidities such as type 2 diabetes, cardiovascular and neurodegenerative diseases. Here, we review the literature for the role of adipokines as key mediators of the communication between periphery and CNS in health and disease. We will focus on the actions of leptin and adiponectin, two of the most abundant and well studied adipokines, in the brain, with particular emphasis on how altered signaling of these adipokines in obesity may lead to cognitive dysfunction and augmented risk for Alzheimer's disease. A better understanding of adipokine biology in brain disorders may prove of major relevance to diagnostic, prevention and therapy.