Inhibition of high-fat diet-induced obesity via reduction of ER-resident protein Nogo occurs through multiple mechanisms.

Obesity is a risk factor for insulin resistance, type 2 diabetes, and cardiovascular diseases. Reticulon-4 (Nogo) is an endoplasmic reticulum-resident protein with unclear functions in obesity. Herein, we investigated the effect of Nogo on obesity and associated metabolic disorders. Human serum samples were collected to explore the relationship between circulating Nogo-B and body mass index value. Nogo-deficient and WT littermate control mice were fed normal chow or high-fat diet (HFD) for 14 weeks, and HFD-induced obese C57BL/6J mice were injected scrambled or Nogo siRNA for 2 weeks. We found that in human and mouse serum, Nogo-B was positively correlated to body mass index/bodyweight and lipid profiles. Reduced Nogo (by genetic deletion or siRNA transfection) protected mice against HFD-induced obesity and related metabolic disorders. We demonstrate that Nogo deficiency reversed HFD-induced whitening of brown adipose tissue, thereby increasing thermogenesis. It also ameliorated lipid accumulation in tissues by activating the adiponectin-adiponectin receptor 1-AMP-activated kinase α signaling axis. Finally, Nogo deficiency potently reduced HFD-induced serum proinflammatory cytokines and infiltration of macrophages into metabolic organs, which is related to enhanced NF-κB p65 degradation via the lysosome pathway. Collectively, our study suggests that reduced levels of Nogo protect mice against HFD-induced obesity by increasing thermogenesis and energy metabolism while inhibiting NF-κB-mediated inflammation. Our results indicate that inhibition of Nogo may be a potential strategy for obesity treatment.

A Sensitive and Simple Enzyme-Linked Immunosorbent Assay Using Polymer as Carrier.

In this study, a new and sensitive enzyme-linked immunosorbent assay (ELISA) was developed by introducing a polymer as a reaction carrier. The results suggest that the newly developed ELISA method is more convenient than the existing paper-based ELISA method and applicable to a wider range of environments. In addition, the sensitivity of the new method is much higher than that of the existing paper-based ELISA method and even higher than that of the traditional ELISA method.

Towards precision medicine for stress disorders: diagnostic biomarkers and targeted drugs.

The biological fingerprint of environmental adversity may be key to understanding health and disease, as it encompasses the damage induced as well as the compensatory reactions of the organism. Metabolic and hormonal changes may be an informative but incomplete window into the underlying biology. We endeavored to identify objective blood gene expression biomarkers for psychological stress, a subjective sensation with biological roots. To quantify the stress perception at a particular moment in time, we used a simple visual analog scale for life stress in psychiatric patients, a high-risk group. Then, using a stepwise discovery, prioritization, validation, and testing in independent cohort design, we were successful in identifying gene expression biomarkers that were predictive of high-stress states and of future psychiatric hospitalizations related to stress, more so when personalized by gender and diagnosis. One of the top biomarkers that survived discovery, prioritization, validation, and testing was FKBP5, a well-known gene involved in stress response, which serves as a de facto reassuring positive control. We also compared our biomarker findings with telomere length (TL), another well-established biological marker of psychological stress and show that newly identified predictive biomarkers such as NUB1, APOL3, MAD1L1, or NKTR are comparable or better state or trait predictors of stress than TL or FKBP5. Over half of the top predictive biomarkers for stress also had prior evidence of involvement in suicide, and the majority of them had evidence in other psychiatric disorders, providing a molecular underpinning for the effects of stress in those disorders. Some of the biomarkers are targets of existing drugs, of potential utility in patient stratification, and pharmacogenomics approaches. Based on our studies and analyses, the biomarkers with the best overall convergent functional evidence (CFE) for involvement in stress were FKBP5, DDX6, B2M, LAIR1, RTN4, and NUB1. Moreover, the biomarker gene expression signatures yielded leads for possible new drug candidates and natural compounds upon bioinformatics drug repurposing analyses, such as calcium folinate and betulin. Our work may lead to improved diagnosis and treatment for stress disorders such as PTSD, that result in decreased quality of life and adverse outcomes, including addictions, violence, and suicide.

Impact of RTN4 gene polymorphism and its plasma level on susceptibility to nasopharyngeal carcinoma: A case-control study.

The RTN4 gene plays a role in the development and progression of cancer. This case-control study aimed to investigate the association between the RTN4 gene polymorphism and its plasma level with the risk of nasopharyngeal carcinoma (NPC) in a Chinese population.RTN4 gene polymorphisms (rs2920891, rs17046583, rs117465650, rs10496040, and rs2588519) in 220 patients with NPC and 300 healthy controls were analyzed using Snapshot single-nucleotide polymorphism genotyping assays. The plasma level of RTN4 was measured using the enzyme-linked immunosorbent assay.The allele frequencies of RTN4 gene polymorphisms showed no significant difference between the patients and controls (P > .05). Nevertheless, the rs2920891 polymorphism in a dominant model (A/C+C/C) and codominant model (A/C) was significantly associated with the susceptibility to NPC (P = .017, odds ratio [OR] = 1.54, 95% confidence interval [CI] = 1.08-2.21 and P = .034, OR = 1.64, 95% CI = 1.13-2.38, respectively). The plasma level of RTN4 was significantly higher in patients with NPC in comparison with the controls (P < .001). Furthermore, we observed that patients with NPC carrying the rs2920891 A/C+C/C genotype had a higher RTN4 level than those carrying the A/A genotype (P < .001).Our findings indicated that the rs2920891 polymorphism may be associated with increased susceptibility to NPC, possibly by increasing plasma RTN4.

Plasma Nogo-A and placental growth factor levels are associated with portal hypertension in patients with liver cirrhosis.

BACKGROUND: Clinically significant portal hypertension (CSPH) and severe portal hypertension (SPH) increase the risk for decompensation and life-threatening complications in liver cirrhosis. Pathologic angiogenesis might contribute to the formation of these conditions. Placental growth factor (PlGF) and Nogo-A protein are biomarkers of pathological angiogenesis, but data on their role in liver cirrhosis and portal hypertension is scarce. AIM: To determine plasma levels of PlGF and Nogo-A in patients with liver cirrhosis, CSPH, SPH and potential to predict portal hypertension. METHODS: A cohort of 122 patients with hepatitis C virus and/or alcohol-induced liver cirrhosis with characterized hepatic venous pressure gradient (HVPG) were included in the study. Demographic data, medical history, Child-Turcotte-Pugh and Model of End Stage liver disease score, clinical chemistry, liver stiffness values were recorded on the day of the procedure prior HVPG measurement. The degree of portal hypertension was determined by the invasive HVPG measurement. Nogo-A and PlGF plasma levels were evaluated using enzyme linked immunosorbent assay. The control group consisted of 30 healthy age- and sex- matched individuals. RESULTS: Peripheral PlGF levels were higher and Nogo-A levels were lower in patients with liver cirrhosis (23.20 vs 9.85; P < 0.0001 and 2.19 vs 3.12; P = 0.004 respectively). There was a positive linear correlation between peripheral levels of PlGF and HVPG (r = 0.338, P = 0.001) and negative linear correlation between the peripheral Nogo-A levels and HVPG (r = -0.267, P = 0.007). PlGF levels were higher in CSPH and SPH (P = 0.006; P < 0.0001) whereas Nogo-A levels were lower (P = 0.01; P < 0.033). Area under the curve for the diagnosis of CSPH for PlGF was 0.68 (P = 0.003) and for Nogo-A - 0.67 (P = 0.01); for SPH 0.714 (P < 0.0001) and 0.65 (P = 0.014) respectively. PlGF levels were higher and Nogo-A levels were lower in patients with esophageal varices (P < 0.05). PlGF cut-off value of 25 pg/mL distinguished patients with CSPH at 55.7% sensitivity and 76.7% specificity; whereas Nogo-A cut-off value of 1.12 ng/mL was highly specific (93.1%) for the diagnosis of CSPH. CONCLUSION: Plasma PlGF levels were higher while Nogo-A levels were lower in patients with liver cirrhosis and portal hypertension. Biomarkers showed moderate predictive value in determining CSPH and SPH.

Overexpression of Circulating Soluble Nogo-B Improves Diabetic Kidney Disease by Protecting the Vasculature.

Damage to the vasculature is the primary mechanism driving chronic diabetic microvascular complications such as diabetic nephropathy, which manifests as albuminuria. Therefore, treatments that protect the diabetic vasculature have significant therapeutic potential. Soluble neurite outgrowth inhibitor-B (sNogo-B) is a circulating N-terminus isoform of full-length Nogo-B, which plays a key role in vascular remodeling following injury. However, there is currently no information on the role of sNogo-B in the context of diabetic nephropathy. We demonstrate that overexpression of sNogo-B in the circulation ameliorates diabetic kidney disease by reducing albuminuria, hyperfiltration, and abnormal angiogenesis and protecting glomerular capillary structure. Systemic sNogo-B overexpression in diabetic mice also associates with dampening vascular endothelial growth factor-A signaling and reducing endothelial nitric oxide synthase, AKT, and GSK3ß phosphorylation. Furthermore, sNogo-B prevented the impairment of tube formation, which occurred when human endothelial cells were exposed to sera from patients with diabetic kidney disease. Collectively, these studies provide the first evidence that sNogo-B protects the vasculature in diabetes and may represent a novel therapeutic target for diabetic vascular complications.

The role of novel cytokines in inflammation: Defining peripheral artery disease among patients with coronary artery disease.

Coronary artery disease (CAD) patients with concomitant peripheral artery disease (PAD) experience more extensive and calcified atherosclerosis, greater lesion progression and more common coronary events compared to patients with CAD only. To characterize the distinct features of this aggressive atherosclerotic disease, we studied novel cytokines that code different stages of atherogenesis. One hundred and eighty consecutive subjects (60 patients into each group of CAD+PAD, CAD and controls) were recruited among patients with stable angina pectoris scheduled for coronary angiography. An ankle-brachial index (ABI) ≤0.9 was determined as occlusive PAD. Fasting serum tumor necrosis factor (TNF)-like antigen 1A (TL1A) and its receptor death receptor 3 (DR3), NOGO-B (reticulon 4B) and its receptor NUS1, high-sensitivity C-reactive protein (hsCRP), A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 1, 4, 5 and interleukin (IL) 6 levels were determined. Serum hsCRP and DR3/TL1A concentrations were similar and higher than controls in the CAD and CAD+PAD groups. Levels of NOGO-B and its receptor NUS1 were increased and ADAMTS-5 was decreased in patients with CAD+PAD. Independent predictors of ABI in multivariate analysis were smoking (B = -0.13, p = 0.04), NUS1 (B = -0.88, p < 0.001), ADAMTS-5 (B = 0.63, p < 0.001) and SYNTAX score (B = -0.26, p < 0.001). Similarly, smoking (OR = 5.5, p = 0.019), SYNTAX score (OR = 1.2, p < 0.001), NUS1 (OR = 14.4, p < 0.001), ADAMTS-5 (OR = 1.1, p < 0.001) and age (OR = 1.1, p = 0.042) independently predicted the involvement of peripheral vasculature in logistic regression. The diagnostic performance of these cytokines to discriminate CAD+PAD were AUC 0.79 ( p < 0.001) for NUS1 and 0.37 ( p = 0.013) for ADAMTS-5. We report herein that circulating cytokines can give clues to the ongoing atherosclerotic process and the extent of vascular involvement in which distinct features of ADAMTS-5 and NUS1 make them promising cytokines for future research.

Serum levels of glial fibrillary acidic protein and Nogo-A in children with autism spectrum disorders.

CONTEXT: Improved biomarkers would facilitate the diagnosis and treatment of autism spectrum disorders (ASD). OBJECTIVE: Our objective was to examine the levels of Nogo-A and glial fibrillary acidic protein (GFAP) in children with ASD. MATERIALS AND METHODS: Serum concentrations of GFAP and Nogo-A were determined by enzyme-linked immunosorbent assay. RESULTS: In this preliminary study, we found that serum Nogo-A was not found significantly different between groups, while serum levels of GFAP were significantly lower in ASD than controls. DISCUSSION AND CONCLUSIONS: It will be of great interest to determine other potential causes of elevated serum levels of GFAP, and whether this elevation has any phenotypic effect.