Ali Tiss

• PhD
• Bioseparation Sales Specialist at Waters Corporation

Objective: The corticotropin-releasing factor neuropeptides (corticotropin-releasing hormone [CRH] and urocortin [UCN]-1,2,3) and spexin contribute to the regulation of energy balance and inhibit food intake in mammals. However, the status of these neuropeptides in children with overweight has yet to be elucidated. This study investigated the effe...

The corticotropin-releasing hormone (CRH) and urocortins (UCNs) have been implicated in energy homeostasis and the cellular stress response. However, the expression of these neuropeptides in children remains unclear. Therefore, we determined the impact of obesity on their expression in 40 children who were normal weight, overweight, and had obesity...

The neuropeptide urocortin 3 (UCN3) has a beneficial effect on metabolic disorders, such as obesity, diabetes, and cardiovascular disease. It has been reported that UCN3 regulates insulin secretion and is dysregulated with increasing severity of obesity and diabetes. However, its function in the adipose tissue is unclear. We investigated the overex...

Introduction Diabetic foot ulcers (DFU) and infection (DFI) are a major diabetes-related problem around the world due to the high prevalence of diabetes in the population. The aim of our study was to determine the microbiological profile of infected ulcers in patients attending Dasman Diabetes Institute (DDI) clinics in Kuwait and to analyze the di...

Abstract Fetuin-A (Fet-A) was one of the first hepatokines to be reportedly linked to metabolic diseases. Fet-A was also suggested to be an adipokine, but its expression in the adipose tissue remains debatable. Here we compared the expression of Fet-A between human and mice adipose tissue biopsies as well as among human subcutaneous tissue and visc...

Background: Obstructive sleep apnea (OSA) is caused by partial or complete obstruction of the upper airways. Corrective surgeries aim at removing obstructions in the nasopharynx, oropharynx, and hypopharynx. OSA is associated with an increased risk of various metabolic diseases. Our objective was to evaluate the effect of surgery on the plasma meta...

Background: Obstructive sleep apnea (OSA) is caused by partial or complete obstruction of the upper airways. Corrective surgeries aim at removing obstructions in the nasopharynx, oropharynx, and hypopharynx. OSA is associated with increased risk of various metabolic diseases. Our objective was to evaluate the effect of surgery on the plasma metabol...

Spexin is a novel neuropeptide playing an emerging role in metabolic diseases such as obesity and diabetes via involvement in energy homeostasis and food intake. The present study investigated the effects of obesity and type 2 diabetes (T2D) on circulating levels of spexin and its modulation by physical exercise. Normal-weight (n = 50) and obese ad...

Lipotoxicity, an important factor in the pathogenesis of diabetes, leads to defective β-cell proliferation and increased apoptosis. Glucagon-like peptide-1 (GLP-1) analogs, which are used to treat type 2 diabetes, reduce endoplasmic reticulum stress and inflammation in pancreatic β-cells and improve their survival. However, their effects on the hea...

Epoxide hydrolase 2 (EPHX2) is an emerging therapeutic target in several immunometabolic disorders. EPHX2 metabolizes anti-inflammatory epoxyeicosatrienoic acids into pro-inflammatory diols. The contribution of EPHX2 activity to human obesity remains unexplored. We compared the expression of EPHX2 between lean and obese humans (n = 20 each) in subc...

Cardiovascular disease (CVD) risks persist in patients despite treatment. CVD susceptibility also varies with sex and ethnicity and is not entirely explained by conventional CVD risk factors. The aim of the present study was to identify novel CVD candidate markers in circulating Peripheral blood mononuclear cells (PBMCs) and plasma from Arab obese...

Urocortin3 (UCN3) regulates metabolic functions and is involved in cellular stress response. Although UCN3 is expressed in human adipose tissue, the association of UCN3 with obesity and diabetes remains unclear. This study investigated the effects of Type 2 diabetes (T2D) and increased body weight on the circulatory and subcutaneous adipose tissue...

Despite reports on the occurrence of Granulicatella adiacens in infective endocarditis, few mechanistic studies on its virulence characteristics or pathogenicity are available. Proteins secreted by this species may act as determinants of host-microbe interaction and play a role in virulence. Our aim in this study was to investigate and functionally...

List of proteins identified in G. adiacens secretome. Secretome preparation from G. adiacens was analyzed by LC-MS/MS and further revealed by database search (NCBI-nr).

Background The hepatokine fetuin-A is linked to obesity and type 2 diabetes, but its presence and expression in adipose tissue remain unclear. In this study, we aimed to assess the circulating levels of fetuin-A and its expression in subcutaneous adipose tissue (SAT) from diabetic and non-diabetic obese subjects and their modulation by exercise. M...

Background: Cardiovascular disease (CVD) risks persist in patients despite the use of conventional treatments. This might be due to chronic inflammation as reflected in epidemiological studies associating circulating low-grade inflammatory markers with CVD recurrent events. Here, we explored this potential link by assessing plasma dual-specificity...

The chemokine CCL2 (also known as MCP-1) is a key regulator of monocyte infiltration into adipose tissue, which plays a central role in the pathophysiology of obesity-associated inflammation and insulin resistance. It remains unclear how CCL2 production is upregulated in obese humans and rodents. Because elevated levels of the free fatty acid (FFA)...

Heat shock protein 60 (HSP60) is a key protein in the crosstalk between cellular stress and inflammation. However, the status of HSP60 in diabetes and obesity is unclear. In the present study, we investigated the hypothesis that HSP60 expression levels in the adipose tissue of human obese adults with and without diabetes are different and physical...

Functional foods contain biologically active ingredients associated with physiological health benefits for preventing and managing chronic diseases, such as type 2 diabetes mellitus (T2DM). A regular consumption of functional foods may be associated with enhanced anti-oxidant, anti-inflammatory, insulin sensitivity, and anti-cholesterol functions,...

Background Obesity and its co-morbidities are characterized by a chronic low-grade inflammatory state, uncontrolled expression of metabolic measurements and dis-regulation of various forms of stress response. However, the contribution and correlation of inflammation, metabolism and stress responses to the disease are not fully elucidated. In this p...

Background: Obesity and its co-morbidities are characterized by a chronic low-grade in amatory state, uncontrolled expression of metabolic measurements and dis-regulation of various forms of stress response. However, the contribution and correlation of inflammation, metabolism and stress responses to the disease are not fully elucidated. In this pa...

Objective ANGPTL7 is a member of the Angiopoietin-like (ANGPTL) protein family that is composed of eight proteins (1–8). Increasing evidence is associating ANGPTL proteins to obesity and insulin resistance. The biological role of ANGPTL7 is yet to be understood except for a recently proposed role in the pathophysiology of glaucoma. This study was d...

Diabetic patients have higher risk of urinary tract infection (UTI). In the present study, we investigated the impact of glycemic control in diabetic patients on UTI prevalence, type of strains, and their antimicrobial drugs susceptibility. This study was conducted on urine samples from 722 adult diabetic patients from which 252 (35%) samples were...

Several lines of evidence implicated the pathophysiological role of the endoplasmic reticulum (ER) stress in obesity-induced insulin resistance and diabetes. Using a targeted transcriptomic profiling approach consisting of the Heat Shock Response RT2 Profiler PCR Array, we previously reported impaired expression of DNAJB3/Hsp-40 cochaperone in obes...

Heat shock response (HSR) is an essential host-defense mechanism that is dysregulated in obesity-induced insulin resistance and type 2 diabetes (T2D). Our recent data demonstrated that DNAJB3 was downregulated in obese human subjects and showed negative correlation with inflammatory markers. Nevertheless, DNAJB3 expression pattern in diabetic subje...

Diabetes is an increasing worldwide problem leading to major associated health issues and increased health care costs. In 2012, 9.3% of the American population was affected by diabetes, according to the American Diabetes Association, with 1.7 million of new cases since during the year (www.diabetes.org). Proteome initiatives can provide a deeper un...

. The impact of gender difference on the association between metabolic stress and cardiovascular disease (CVD) remains unclear. We have investigated, for the first time, the gender effect on the oxidative and inflammatory stress responses and assessed their correlation with classical cardiometabolites in Arab population. Methods . A total of 378 ad...

Chronic low-grade inflammation and uncontrolled metabolic stress response are cardinal features of obesit y ; a major risk factor for the development diabetes. D ual specificit y protein phosphatase 1 (DUSP1) is implicated in metabolism and energ y expenditure. Mice lacking DUSP1 are resistant to high fat diet-induced obesit y. However, the express...

Chronic low-grade inflammation and uncontrolled metabolic stress response are cardinal features of obesity; a major risk factor for the development of diabetes. Dual specificity protein phosphatase 1 (DUSP1) is implicated in metabolism and energy expenditure. Mice lacking DUSP1 are resistant to high fat diet-induced obesity. However, the expression...

Ghrelin is a stomach produced hormone that has been shown to have protective role against development of CVD which is a leading cause of death in the Arab world. The objective of this study is to examine the gender difference in association between traditional CVD risk factors and plasma ghrelin among Arabs. 359 Arab residents in Kuwait participate...

Background Obesity is characterized by a chronic low-grade inflammation and altered stress responses in key metabolic tissues. Impairment of heat shock response (HSR) has been already linked to diabetes and insulin resistance as reflected by decrease in heat shock proteins (HSPs) expression. However, the status of HSR in non-diabetic human obese ha...

RANTES and its CCR5 receptor trigger inflammation and its progression to insulin resistance in obese. In the present study, we investigated for the first time the effect of physical exercise on the expression of RANTES and CCR5 in obese humans. Fifty-seven adult nondiabetic subjects (17 lean and 40 obese) were enrolled in a 3-month supervised physi...

Early stage detection of cancer is the key to provide a better outcome for therapeutic intervention. Proteomic technologies hold recently great promise in the search of new clinical biomarkers for the early detection and diagnosis of cancer or for the development of new vaccines. In this perspective, we will present our recent work in improving ear...

Early-stage detection of cancer is the key to provide a better outcome for therapeutic intervention. Most routine screening tools for cancer detection are largely based on examination of cell morphology, tissue histology, and measurement of serum markers, which lack sufficient sensitivity and/or specificity for early detection of cancer. Indeed, mo...

Early stage detection of cancer is the key to provide a better outcome for therapeutic intervention. Most routine screening tools for cancer detection are largely based on examination of cell morphology, tissue histology and measurement of serum markers, which lack sufficient sensitivity and/or specificity for early detection of cancer. Indeed, mos...

Sedentary lifestyle and excessive energy intake are prominent contributors to obesity; a major risk factors for the development of insulin resistance, type 2 diabetes and cardiovascular diseases. Elucidating the molecular mechanisms underlying these chronic conditions is of relevant importance as it might lead to the identification of novel anti-ob...

Obesity is a major risk factor for a myriad of disorders such as insulin resistance and diabetes. The mechanisms underlying these chronic conditions are complex but low grade inflammation and alteration of the endogenous stress defense system are well established. Previous studies indicated that impairment of HSP-25 and HSP-72 was linked to obesity...

This paper describes the methodology of providing multiprobability predictions for proteomic mass spectrometry data. The methodology is based on a newly developed machine learning framework called Venn machines. Is allows to output a valid probability interval. The methodology is designed for mass spectrometry data. For demonstrative purposes, we a...

This paper describes the methodology of providing multiprobability predictions for proteomic mass spectrometry data. The methodology is based on a newly developed machine learning framework called Venn machines. They allow us to output a valid probability interval. We apply this methodology to mass spectrometry data sets in order to predict the dia...

The work describes an application of a recently developed machine-learning technique called Mondrian predictors to risk assessment of ovarian and breast cancers. The analysis is based on mass spectrometry profiling of human serum samples that were collected in the United Kingdom Collaborative Trial of Ovarian Cancer Screening. The work describes th...

A nested case-control discovery study was undertaken to test whether information within the serum peptidome can improve on the utility of CA125 for early ovarian cancer detection. High-throughput matrix-assisted laser desorption ionisation mass spectrometry (MALDI-MS) was used to profile 295 serum samples from women pre-dating their ovarian cancer...

Differential MS analysis of blood samples from diseased and control subjects is increasingly being employed in the hunt for biomarkers that can detect disease at an early stage. For diagnostic tests, in particular for population screening, robust protocols are required that can offer high-throughput analysis, ideally at high mass spectrometric sens...

Diabetes like many diseases and biological processes is not mono-causal. On the one hand multi-factorial studies with complex experimental design are required for its comprehensive analysis. On the other hand, the data from these studies often include a substantial amount of redundancy such as proteins that are typically represented by a multitude...

Peak alignment. Visualization of the results of the peak alignment method. The heuristic algorithm used for peak alignment is presented in pseudo-code.

Results for Genotype. Scatter plot of peak intensity values for peaks 3388 and 5029 and peak intensities profile for peak 3388. The peaks are in the list of the most significant results for the experimental factor genotype.

Our objective was to test the performance of CA125 in classifying serum samples from a cohort of malignant and benign ovarian cancers and age-matched healthy controls and to assess whether combining information from matrix-assisted laser desorption/ionization (MALDI) time-of-flight profiling could improve diagnostic performance. Serum samples from...

MALDI MS profiling, using easily available body fluids such as blood serum, has attracted considerable interest for its potential in clinical applications. Despite the numerous reports on MALDI MS profiling of human serum, there is only scarce information on the identity of the species making up these profiles, particularly in the mass range of lar...

The serum peptidome may be a valuable source of diagnostic cancer biomarkers. Previous mass spectrometry (MS) studies have suggested that groups of related peptides discriminatory for different cancer types are generated ex vivo from abundant serum proteins by tumor-specific exopeptidases. We tested 2 complementary serum profiling strategies to see...

The inhibitory effects of tetrahydrolipstatin (THL) on the hydrolytic activity of human pancreatic lipase (HPL) and T. lanuginosa lipase (TLL) on various lipidic substrates ‘poisoned’ with THL as previously described was studied, using either the pH-stat, monomolecular film or oil drop technique.Prior to adding lipase (method C), an ethanolic solut...

Tetrahydrolipstatin (THL, Orlistat) is a potent inhibitor of gastrointestinal lipases. Using the pH-stat technique we report that, in the absence of substrate, THL (at a molar excess of 100) inhibits rapidly (after few minutes of incubation) human pancreatic lipase (HPL). Bile salts over their critical micellar concentration (CMC) were found to acc...

MS is an important analytical tool in clinical proteomics, primarily in the disease-specific discovery, identification and characterisation of proteomic biomarkers and patterns. MS-based proteomics is increasingly used in clinical validation and diagnostic method development. The latter departs from the typical application of MS-based proteomics by...

Blood represents a convenient diagnostic specimen for clinical analysis. Serum metabolites and peptides have the potential to serve as reliable indicators of progression from a normal to a diseased state. However, the presence of salts, lipids and high concentrations of protein in blood serum can adversely affect its mass spectrometric profiling, a...

Ferric uptake regulator protein (Fur) is activated by its cofactor iron to a state that binds to a specific DNA sequence called 'Fur box'. Using mass spectrometry-based methods, we showed that Tyr 55 of Escherichia coli Fur, as well as the two thymines in positions 18 and 19 of the consensus Fur Box, are involved with binding. A conformational mode...

Introduction 3-D Structure of Human Pancreatic Lipase3-D Structure of Human Gastric LipaseMethods for Lipase Inhibition Method A: Lipase/Inhibitor Pre-incubationMethod B: Inhibition During Lipolysis“Pre-poisoned” Interfaces Method CMethod DInhibition of Lipases by E600 and Various Phosphonates Inhibition of PPL, HGL and RGL by Radiolabeled E600Inte...

The transfer of radiolabelled orlistat ([14C]orlistat), a potent gastrointestinal lipase inhibitor, through an oil-water interface from a single oil droplet to an aqueous phase was investigated, using an oil drop tensiometer. The absolute transfer fluxes were found to be very low, even in the presence of micellar concentrations of bile salts, which...

We investigated the effects of Gum Arabic (GA) on the interfacial binding and activity of human pancreatic lipase (HPL) on trioctanoylglycerol (TC8) emulsion. Using the pH-stat technique, in the presence of sodium taurodeoxycholate (NaTDC) at concentration of 0.5 mM or higher, GA had no effect on the HPL activity measured in the presence of colipas...

This study was done to better understand how lipases are activated at an interface. We investigated the conformational and solvation changes occurring during the adsorption of Humicola lanuginosa lipase (HLL) onto a hydrophobic surface using Fourier transform infrared-attenuated total reflection spectroscopy. The hydrophobic surfaces were obtained...

We investigated the surface behavior of gum Arabic (GA) as well as its effects on the lipolytic activity of human pancreatic lipase (HPL) and Humicola lanuginosa lipase (HLL), using emulsions of triacylglycerols (TAG) with various chain lengths. The effects of GA on the interfacial binding of HPL were also investigated. In the presence of 4 mM sodi...

The surface behaviour of two bile salts, sodium deoxycholate (NaDC) and sodium taurodeoxycholate (NaTDC), as well as that of tetrahydrolipstatin (THL), a potent gastrointestinal lipase inhibitor, was studied at air/water and oil/water interfaces, using interfacial tensiometry methods. The surface behaviour of NaDC and NaTDC was comparable at both o...

We report a generally applicable protein insertion process leading to the formation of a close packed protein single layer within a freestanding surfactant bilayer. Very high packing fractions can be obtained in a controlled manner, simply by adjusting the protein chemical potential in the solution. We apply this method to the confinement of a mode...

As the in-vivo study is made difficult by the complexity of the cell machinery, fabrication of in-vitro model system could simplify the investigation of the physical properties of proteins. Adsorption of proteins at the air/water interface has now been widely used in the study of surface activity of biological compound. Beside this usual approach,...