Inflammatory protein signatures in individuals with obesity and metabolic syndrome

There is variability in the metabolic health status among individuals presenting with obesity; some may be metabolically healthy, while others may have developed the metabolic syndrome, a cluster including insulin resistance, hypertension, dyslipidemia, and increased risk of cardiovascular disease and type 2 diabetes. The mechanisms contributing to this metabolic heterogeneity are not fully understood. To address this question, plasma samples from 48 individuals with BMI ≥ 35 kg/m2 were examined (27 with and 21 without metabolic syndrome). Fasting plasma samples were subjected to Olink proteomics analysis for 184 cardiometabolic and inflammation-enriched proteins. Data analysis showed a clear differentiation between the two groups with distinct plasma protein expression profiles. Twenty-four proteins were differentially expressed (DEPs) between the two groups. Pathways related to immune cell migration, leukocyte chemotaxis, chemokine signaling, mucosal inflammatory response, tissue repair and remodeling were enriched in the group with metabolic syndrome. Functional analysis of DEPs revealed upregulation of 15 immunological pathways. The study identifies some of the pathways that are altered and reflect metabolic health in individuals with obesity. This provides valuable insights into some of the underlying mechanisms and can lead to identification of therapeutic targets to improve metabolic health in individuals with obesity.

Neuroepigenetics of ageing and neurodegeneration-associated dementia: An updated review

Gene expression is tremendously altered in the brain during memory acquisition, recall, and forgetfulness. However, non-genetic factors, including environmental elements, epigenetic changes, and lifestyle, have grabbed significant attention in recent years regarding the etiology of neurodegenerative diseases (NDD) and age-associated dementia. Epigenetic modifications are essential in regulating gene expression in all living organisms in a DNA sequence-independent manner. The genes implicated in ageing and NDD-related memory disorders are epigenetically regulated by processes such as DNA methylation, histone acetylation as well as messenger RNA editing machinery. The physiological and optimal state of the epigenome, especially within the CNS of humans, plays an intricate role in helping us adjust to the changing environment, and alterations in it cause many brain disorders, but the mechanisms behind it still need to be well understood. When fully understood, these epigenetic landscapes could act as vital targets for pharmacogenetic rescue strategies for treating several diseases, including neurodegeneration- and age-induced dementia. Keeping this objective in mind, this updated review summarises the epigenetic changes associated with age and neurodegeneration-associated dementia.

An integrated multi-omic approach demonstrates distinct molecular signatures between human obesity with and without metabolic complications: a case-control study

OBJECTIVES

To examine the hypothesis that obesity complicated by the metabolic syndrome, compared to uncomplicated obesity, has distinct molecular signatures and metabolic pathways.

METHODS

We analyzed a cohort of 39 participants with obesity that included 21 with metabolic syndrome, age-matched to 18 without metabolic complications. We measured in whole blood samples 754 human microRNAs (miRNAs), 704 metabolites using unbiased mass spectrometry metabolomics, and 25,682 transcripts, which include both protein coding genes (PCGs) as well as non-coding transcripts. We then identified differentially expressed miRNAs, PCGs, and metabolites and integrated them using databases such as mirDIP (mapping between miRNA-PCG network), Human Metabolome Database (mapping between metabolite-PCG network) and tools like MetaboAnalyst (mapping between metabolite-metabolic pathway network) to determine dysregulated metabolic pathways in obesity with metabolic complications.

RESULTS

We identified 8 significantly enriched metabolic pathways comprising 8 metabolites, 25 protein coding genes and 9 microRNAs which are each differentially expressed between the subjects with obesity and those with obesity and metabolic syndrome. By performing unsupervised hierarchical clustering on the enrichment matrix of the 8 metabolic pathways, we could approximately segregate the uncomplicated obesity strata from that of obesity with metabolic syndrome.

CONCLUSIONS

The data suggest that at least 8 metabolic pathways, along with their various dysregulated elements, identified via our integrative bioinformatics pipeline, can potentially differentiate those with obesity from those with obesity and metabolic complications.

Increase in repulsive guidance molecule-a (RGMa) in lacunar and cortical stroke patients is related to the severity of the insult

Repulsive guidance molecule-a (RGMa) inhibits angiogenesis and increases inflammation. Animal models of cerebral ischemia have shown that an increased expression of RGMa leads to larger infarction and its inhibition attenuates effects of ischemia. We report on the relationship of RGMa to stroke types and severity. This is a prospective study in patients admitted to the stroke service in Qatar. We collected the clinical determinants, including NIHSS at admission, imaging and outcome at discharge and 90-days. RGMa levels were determined by measuring mRNA levels extracted from peripheral blood mononuclear cells (PBMCs) within 24 h of onset and at 5 days. There were 90 patients (lacunar: 64, cortical: 26) and 35 age-matched controls. RGMa mRNA levels were significantly higher in the stroke patients: day 1: 1.007 ± 0.13 versus 2.152 ± 0.19 [p < 0.001] and day-5: 3.939 ± 0.36 [p < 0.0001]) and significantly higher in patients with severe stroke (NIHSS ≥ 8) compared to milder symptoms (NIHSS < 8) at day 1 (NIHSS ≥ 8: 2.563 ± 0.36; NIHSS < 8: 1.947 ± 0.2) and day 5 (NIHSS ≥ 8: 5.25 ± 0.62; NIHSS < 8: 3.259 ± 0.419). Cortical stroke patients had marginally higher RGMa mRNA levels compared to lacunar stroke at day 1 (cortical stroke: 2.621 ± 0.46 vs lacunar stroke: 1.961 ± 0.19) and day 5 (cortical stroke: 4.295 ± 0.76 vs lacunar stroke: 3.774 ± 0.39). In conclusion, there is an increase in the level of RGMa mRNA in patients with acute stroke and seen in patients with lacunar and cortical stroke. The increase in RGMa mRNA levels is related to the severity of the stroke and increases over the initial 5 days. Further studies are required to determine the effects of the increase in RGMa on stroke recovery.

Dysregulated Metabolic Pathways in Subjects with Obesity and Metabolic Syndrome

Background: Obesity coexists with variable features of metabolic syndrome, which is associated with dysregulated metabolic pathways. We assessed potential associations between serum metabolites and features of metabolic syndrome in Arabic subjects with obesity. Methods: We analyzed a dataset of 39 subjects with obesity only (OBO, n = 18) age-matched to subjects with obesity and metabolic syndrome (OBM, n = 21). We measured 1069 serum metabolites and correlated them to clinical features. Results: A total of 83 metabolites, mostly lipids, were significantly different (p < 0.05) between the two groups. Among lipids, 22 sphingomyelins were decreased in OBM compared to OBO. Among non-lipids, quinolinate, kynurenine, and tryptophan were also decreased in OBM compared to OBO. Sphingomyelin is negatively correlated with glucose, HbA1C, insulin, and triglycerides but positively correlated with HDL, LDL, and cholesterol. Differentially enriched pathways include lysine degradation, amino sugar and nucleotide sugar metabolism, arginine and proline metabolism, fructose and mannose metabolism, and galactose metabolism. Conclusions: Metabolites and pathways associated with chronic inflammation are differentially expressed in subjects with obesity and metabolic syndrome compared to subjects with obesity but without the clinical features of metabolic syndrome.

Characteristic MicroRNAs Linked to Dysregulated Metabolic Pathways in Qatari Adult Subjects With Obesity and Metabolic Syndrome

BACKGROUND

Obesity-associated dysglycemia is associated with metabolic disorders. MicroRNAs (miRNAs) are known regulators of metabolic homeostasis. We aimed to assess the relationship of circulating miRNAs with clinical features in obese Qatari individuals.

METHODS

We analyzed a dataset of 39 age-matched patients that includes 18 subjects with obesity only (OBO) and 21 subjects with obesity and metabolic syndrome (OBM). We measured 754 well-characterized human microRNAs (miRNAs) and identified differentially expressed miRNAs along with their significant associations with clinical markers in these patients.

RESULTS

A total of 64 miRNAs were differentially expressed between metabolically healthy obese (OBO) versus metabolically unhealthy obese (OBM) patients. Thirteen out of 64 miRNAs significantly correlated with at least one clinical trait of the metabolic syndrome. Six out of the thirteen demonstrated significant association with HbA1c levels; miR-331-3p, miR-452-3p, and miR-485-5p were over-expressed, whereas miR-153-3p, miR-182-5p, and miR-433-3p were under-expressed in the OBM patients with elevated HbA1c levels. We also identified, miR-106b-3p, miR-652-3p, and miR-93-5p that showed a significant association with creatinine; miR-130b-5p, miR-363-3p, and miR-636 were significantly associated with cholesterol, whereas miR-130a-3p was significantly associated with LDL. Additionally, miR-652-3p's differential expression correlated significantly with HDL and creatinine.

CONCLUSIONS

MicroRNAs associated with metabolic syndrome in obese subjects may have a pathophysiologic role and can serve as markers for obese individuals predisposed to various metabolic diseases like diabetes.

Complement C5a and Clinical Markers as Predictors of COVID-19 Disease Severity and Mortality in a Multi-Ethnic Population

Coronavirus disease-2019 (COVID-19) was declared as a pandemic by WHO in March 2020. SARS-CoV-2 causes a wide range of illness from asymptomatic to life-threatening. There is an essential need to identify biomarkers to predict disease severity and mortality during the earlier stages of the disease, aiding treatment and allocation of resources to improve survival. The aim of this study was to identify at the time of SARS-COV-2 infection patients at high risk of developing severe disease associated with low survival using blood parameters, including inflammation and coagulation mediators, vital signs, and pre-existing comorbidities. This cohort included 89 multi-ethnic COVID-19 patients recruited between July 14th and October 20th 2020 in Doha, Qatar. According to clinical severity, patients were grouped into severe (n=33), mild (n=33) and asymptomatic (n=23). Common routine tests such as complete blood count (CBC), glucose, electrolytes, liver and kidney function parameters and markers of inflammation, thrombosis and endothelial dysfunction including complement component split product C5a, Interleukin-6, ferritin and C-reactive protein were measured at the time COVID-19 infection was confirmed. Correlation tests suggest that C5a is a predictive marker of disease severity and mortality, in addition to 40 biological and physiological parameters that were found statistically significant between survivors and non-survivors. Survival analysis showed that high C5a levels, hypoalbuminemia, lymphopenia, elevated procalcitonin, neutrophilic leukocytosis, acute anemia along with increased acute kidney and hepatocellular injury markers were associated with a higher risk of death in COVID-19 patients. Altogether, we created a prognostic classification model, the CAL model (C5a, Albumin, and Lymphocyte count) to predict severity with significant accuracy. Stratification of patients using the CAL model could help in the identification of patients likely to develop severe symptoms in advance so that treatments can be targeted accordingly.

Molecular characteristics of Neisseria meningitidis in Qatar

The aim of the current study is to review the molecular characteristics of Neisseria meningitidis (N. meningitidis) in Hamad Medical Corporation, which is the provider of secondary and tertiary care in the state of Qatar. A total of 39 isolates of N. meningitidis from the period of 2013 to 2018 were revived and identified by Vitek, and susceptibility on the basis of the E test was retrieved from the patient's files. The revived isolates were subjected to multilocus sequence typing. The most common serogroup (19) of N. meningitidis was W135, of which 12 were isolated from blood and CSF. ST-11 was the most predominant ST clonal complex causing N. meningitidis cases (61.53%). Clonal complex ST-41/44 was the second most observed complex (3, 2 of which were related to serogroup B). The most frequent sequence type was 9596 (8 isolates). Determining the molecular pattern of N. meningitidis in Qatar is helpful for understanding the strains circulating in Qatar, and the study of the resistance trend of such strains may be very helpful for empirical treatment of future patients.

Thrombospondin-derived peptide attenuates Sjögren's syndrome-associated ocular surface inflammation in mice

Sjögren's syndrome is the second most common rheumatic disease in which autoimmune response targets exocrine glands (salivary and lacrimal glands) result in clinical symptoms of dry mouth and dry eye. Inflammation of the lacrimal gland induces tear abnormalities that contribute to the inflammation of the ocular surface, which includes ocular mucosa. Thrombospondin-1 (TSP-1) plays a critical regulatory role in the ocular mucosa and as such TSP-1^-/- mice develop spontaneously chronic ocular surface inflammation associated with Sjögren's syndrome. The autoimmune pathology is also accompanied by a peripheral imbalance in regulatory (T_reg ) and inflammatory Th17 effectors. In this study, we demonstrate an in-vitro effect of a CD47-binding TSP-derived peptide in the induction of transforming growth factor (TGF)-β1-secreting forkhead box protein 2 (Foxp3⁺ ) T_regs from activated CD4⁺ CD25^- T cells and the inhibition of pathogenic T helper type 17 (Th17)-promoting interleukin (IL)-23 derived from antigen-presenting cells. The in-vivo administration of this peptide promotes Foxp3⁺ T_reg induction and inhibition of Th17 development. Consistent with these results, topical administration of CD47-binding TSP peptide, both before and after the onset of the disease, attenuates clinical symptoms of SS-associated dry eye in TSP-1^-/- mice. Augmented expression of Foxp3 detected in the draining lymph nodes of TSP peptide -treated mice compared to those treated with control peptide suggests the ability of TSP peptide to restore peripheral immune imbalance. Thus, our results suggest that TSP-derived peptide attenuates Sjögren's syndrome-associated dry eye and autoimmune inflammation by preventing Th17 development while promoting the induction of T_regs . Collectively, our data identify TSP-derived peptide as a novel therapeutic option to treat autoimmune diseases.

Thrombospondin-1-dependent immune regulation by transforming growth factor-β2-exposed antigen-presenting cells

An important role of transforming growth factor-β (TGF-β) in the development of regulatory T cells is well established. Although integrin-mediated activation of latent TGF-β1 is considered essential for the induction of regulatory T (Treg) cells by antigen-presenting cells (APCs), such an activation mechanism is not applicable to the TGF-β2 isoform, which lacks an integrin-binding RGD sequence in its latency-associated peptide. Mucosal and ocular tissues harbour TGF-β2-expressing APCs involved in Treg induction. The mechanisms that regulate TGF-β activation in such APCs remain unclear. In this study, we demonstrate that murine APCs exposed to TGF-β2 in the environment predominantly increase expression of TGF-β2. Such predominantly TGF-β2-expressing APCs use thrombospondin-1 (TSP-1) as an integrin-independent mechanism to activate their newly synthesized latent TGF-β2 to induce Foxp3(+) Treg cells both in vitro and in vivo. Expression of Treg induction by TGF-β2-expressing APCs is supported by a TSP-1 receptor, CD36, which facilitates activation of latent TGF-β during antigen presentation. Our results suggest that APC-derived TSP-1 is essential for the development of an adaptive regulatory immune response induced by TGF-β2-expressing APCs similar to those located at mucosal and ocular sites. These findings introduce the integrin-independent mechanism of TGF-β activation as an integral part of peripheral immune tolerance associated with TGF-β2-expressing tissues.

Conjunctival inflammation in thrombospondin-1 deficient mouse model of Sjögren's syndrome

Lacrimal gland inflammation during autoimmune Sjögren's syndrome (SS) leads to ocular surface inflammation - Keratoconjunctivitis sicca (KCS). This condition afflicts both the cornea and conjunctiva that form the ocular surface. Thrombospondin-1 (TSP-1) deficiency in mice results in lacrimal gland and corneal inflammation that resembles the human disease. In this study we report conjunctival pathology in this mouse model of SS. We found that TSP-1 null mice develop inflammation in the conjunctiva and associated loss of goblet cell function similar to that seen in patients with SS. Increased expression of Th1 (IFN-γ, TNF-α) and Th17 (IL-6, IL-17A) inflammatory cytokines and related transcription factors (Tbet and RORγt) were detected in TSP-1 null conjunctiva as well as their draining lymph nodes (LNs). The conjunctival inflammation was also accompanied by an increase in local lymphatic vessels. Interestingly, migration of antigen-bearing dendritic cells (DCs) from the ocular surface to the LNs was dependent on the TSP-1 available in the tissue. These results not only reveal potential immunopathogenic mechanisms underlying KCS in SS but also highlight the therapeutic potential of TSP-1.

Serine protease activity contributes to control of Mycobacterium tuberculosis in hypoxic lung granulomas in mice

The hallmark of human Mycobacterium tuberculosis infection is the presence of lung granulomas. Lung granulomas can have different phenotypes, with caseous necrosis and hypoxia present within these structures during active tuberculosis. Production of NO by the inducible host enzyme NOS2 is a key antimycobacterial defense mechanism that requires oxygen as a substrate; it is therefore likely to perform inefficiently in hypoxic regions of granulomas in which M. tuberculosis persists. Here we have used Nos2-/- mice to investigate host-protective mechanisms within hypoxic granulomas and identified a role for host serine proteases in hypoxic granulomas in determining outcome of disease. Nos2-/- mice reproduced human-like granulomas in the lung when infected with M. tuberculosis in the ear dermis. The granulomas were hypoxic and contained large amounts of the serine protease cathepsin G and clade B serine protease inhibitors (serpins). Extrinsic inhibition of serine protease activity in vivo resulted in distorted granuloma structure, extensive hypoxia, and increased bacterial growth in this model. These data suggest that serine protease activity acts as a protective mechanism within hypoxic regions of lung granulomas and present a potential new strategy for the treatment of tuberculosis.

Mycobacterium tuberculosis 6-kDa early secreted antigenic target (ESAT-6) protein downregulates lipopolysaccharide induced c-myc expression by modulating the extracellular signal regulated kinases 1/2

Background

Mycobacterium tuberculosis (Mtb) causes death of 2–3 million people every year. The persistence of the pathogenic mycobacteria inside the macrophage occurs through modulation of host cell signaling which allows them, unlike the other non-pathogenic species, to survive inside the host. The secretory proteins of M. tuberculosis have gained attention in recent years both as vaccine candidates and diagnostic tools; they target the immune system and trigger a putatively protective response; however, they may also be involved in the clinical symptoms of the disease.

Results

Our studies showed that RD-1-encoded secretory protein ESAT-6 is involved in modulation of the mitogen-activated protein (MAP) kinase-signaling pathway inside the macrophage. ESAT-6 induced phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2) in the cytoplasm but not in the nucleus, which normally is the case for MAP kinases. ESAT-6 also antagonized LPS-induced ERK1/2 phosphorylation in the nucleus. Stimulation of cells by ESAT-6 along with sodium orthovanadate (a tyrosine phosphatase inhibitor) restored phosphorylation of ERK1/2 in the nucleus, suggesting active dephosphorylation of ERK1/2 by some putative phosphatase(s) in the nucleus. Further, ESAT-6 was found to down regulate the expression of LPS-inducible gene c-myc in an ERK1/2-dependent manner.

Conclusion

This study showed the effect of secretory proteins of M. tuberculosis in the modulation of macrophage signaling pathways particularly ERK1/2 MAP kinase pathway. This modulation appears to be achieved by limiting the ERK1/2 activation in the nucleus which ultimately affects the macrophage gene expression. This could be a mechanism by which secretory proteins of Mtb might modulate gene expression inside the macrophages.

CT in pulmonary hydatid disease: unusual appearances

OBJECTIVE

To study the CT features of pulmonary hydatid disease.

PATIENTS

Thirty-two consecutive patients with surgically proven pulmonary hydatid cysts.

SETTING

SheriKashmir Institute of Medical Sciences, Srinagar, Kashmir, India, a tertiary-care referral center.

INTERVENTIONS

CT of the chest was obtained in all cases on Somatom DR double rotate CT scanner (Siemens; Erlangen, Germany).

RESULTS

Forty cysts of different size and shapes were encountered, 34 of them being ruptured. CT density of the cysts varied from - 42 to 160 Hounsfield units (HU; median, 15.5 HU). Apart from the classically described features of pulmonary hydatid disease, a crescent-shaped rim of air at the lower end of the cyst (inverse crescent sign) was seen in three cysts, and a bleb of air in the wall of two as-yet unruptured cysts (signet ring sign). Thick wall (>10 mm) was observed in four cysts, and each of them had associated evidence of infection.

CONCLUSIONS

Inverse crescent sign, signet ring sign, high CT density, and thick wall should be recognized as features of pulmonary hydatid cysts on CT.

Doctors and the assessment of blood glucose testing sticks: does colour blindness matter?

A group of doctors with congenital colour vision deficiency (CCVD) were compared with a group of controls in their assessment of colour blocks in the colour range of a widely available blood glucose testing stick. The majority of doctors with CCVD agreed with controls on colour matching. However, subjects with severe CCVD tended to match test blocks to a wider range of options than either those with a less severe defect or controls. This paper discusses the implications of these findings.

Doctors and the assessment of clinical photographs--does colour blindness matter?

Colour vision deficiency (CVD) is a common anomaly, especially in the male population. A group of doctors with CVD was compared with a control group. Doctors with CVD differed from controls in respect of their ability to detect, and in their confidence in the assessment of, abnormalities presented in clinical photographs. These findings suggest that doctors with CVD should take special care to ensure safe clinical practice.