Plasma Gelsolin: Indicator of Inflammation and Its Potential as a Diagnostic Tool and Therapeutic Target

Dietary xylo-oligosaccharides and arabinoxylans improved growth efficiency by reducing gut epithelial cell turnover in broiler chickens

BACKGROUND

One of the main roles of the intestinal mucosa is to protect against environmental hazards. Supplementation of xylo-oligosaccharides (XOS) is known to selectively stimulate the growth of beneficial intestinal bacteria and improve gut health and function in chickens. XOS may have an impact on the integrity of the intestinal epithelia where cell turnover is critical to maintain the compatibility between the digestive and barrier functions. The aim of the study was to evaluate the effect of XOS and an arabinoxylan-rich fraction (AXRF) supplementation on gut function and epithelial integrity in broiler chickens.

METHODS

A total of 128 broiler chickens (Ross 308) were assigned into one of two different dietary treatments for a period of 42 d: 1) control diet consisting of a corn/soybean meal-based diet; or 2) a control diet supplemented with 0.5% XOS and 1% AXRF. Each treatment was randomly distributed across 8 pens (n = 8) with 8 chickens each. Feed intake and body weight were recorded weekly. On d 42, one male chicken per pen was selected based on average weight and euthanized, jejunum samples were collected for proteomics analysis.

RESULTS

Dietary XOS/AXRF supplementation improved feed efficiency (P < 0.05) from d 1 to 42 compared to the control group. Proteomic analysis was used to understand the mechanism of improved efficiency uncovering 346 differentially abundant proteins (DAP) (Padj < 0.00001) in supplemented chickens compared to the non-supplemented group. In the jejunum, the DAP translated into decreased ATP production indicating lower energy expenditure by the tissue (e.g., inhibition of glycolysis and tricarboxylic acid cycle pathways). In addition, DAP were associated with decreased epithelial cell differentiation, and migration by reducing the actin polymerization pathway. Putting the two main pathways together, XOS/AXRF supplementation may decrease around 19% the energy required for the maintenance of the gastrointestinal tract.

CONCLUSIONS

Dietary XOS/AXRF supplementation improved growth efficiency by reducing epithelial cell migration and differentiation (hence, turnover), actin polymerization, and consequently energy requirement for maintenance of the jejunum of broiler chickens.

Concentration-dependent alterations in the human plasma proteome following controlled exposure to diesel exhaust

Traffic-related air pollution (TRAP) exposure is associated with systemic health effects, which can be studied using blood-based markers. Although we have previously shown that high TRAP concentrations alter the plasma proteome, the concentration-response relationship between blood proteins and TRAP is unexplored in controlled human exposure studies. We aimed to identify concentration-dependent plasma markers of diesel exhaust (DE), a model of TRAP. Fifteen healthy non-smokers were enrolled into a double-blinded, crossover study where they were exposed to filtered air (FA) and DE at 20, 50 and 150 μg/m3 PM2.5 for 4h, separated by ≥ 4-week washouts. We collected blood at 24h post-exposure and used label-free mass spectrometry to quantify proteins in plasma. Proteins exhibiting a concentration-response, as determined by linear mixed effects models (LMEMs), were assessed for pathway enrichment using WebGestalt. Top candidates, identified by sparse partial least squares discriminant analysis and LMEMs, were confirmed using enzyme-linked immunoassays. Thereafter, we assessed correlations between proteins that showed a DE concentration-response and acute inflammatory endpoints, forced expiratory volume in 1 s (FEV1) and methacholine provocation concentration causing a 20% drop in FEV1 (PC20). DE exposure was associated with concentration-dependent alterations in 45 proteins, which were enriched in complement pathways. Of the 9 proteins selected for confirmatory immunoassays, based on complementary bioinformatic approaches to narrow targets and availability of high-quality assays, complement factor I (CFI) exhibited a significant concentration-dependent decrease (-0.02 μg/mL per μg/m3 of PM2.5, p = 0.04). Comparing to FA at discrete concentrations, CFI trended downward at 50 (-2.14 ± 1.18, p = 0.08) and significantly decreased at 150 μg/m3 PM2.5 (-2.93 ± 1.18, p = 0.02). CFI levels were correlated with FEV1, PC20 and nasal interleukin (IL)-6 and IL-1β. This study details concentration-dependent alterations in the plasma proteome following DE exposure at concentrations relevant to occupational and community settings. CFI shows a robust concentration-response and association with established measures of airway function and inflammation.

Deciphering a proteomic signature for the early detection of breast cancer from breast milk: the role of quantitative proteomics

INTRODUCTION

Breast cancer is one of the most prevalent cancers among women in the United States. Current research regarding breast milk has been focused on the composition and its role in infant growth and development. There is little information about the proteins, immune cells, and epithelial cells present in breast milk which can be indicative of the emergence of BC cells and tumors.

AREAS COVERED

We summarize all breast milk studies previously done in our group using proteomics. These studies include 1D-PAGE and 2D-PAGE analysis of breast milk samples, which include within woman and across woman comparisons to identify dysregulated proteins in breast milk and the roles of these proteins in both the development of BC and its diagnosis. Our projected outlook for the use of milk for cancer detection is also discussed.

EXPERT OPINION

Analyzing the samples by multiple methods allows one to interrogate a set of samples with various biochemical methods that complement each other, thus providing a more comprehensive proteome. Complementing methods like 1D-PAGE, 2D-PAGE, in-solution digestion and proteomics analysis with PTM-omics, peptidomics, degradomics, or interactomics will provide a better understanding of the dysregulated proteins, but also the modifications or interactions between these proteins.

Urinary Protein-Biomarkers Reliably Indicate Very Early Kidney Damage in Children With Alport Syndrome Independently of Albuminuria and Inflammation

Introduction

Alport syndrome (AS) is a hereditary type IV collagen disease. It starts shortly after birth, without clinical symptoms, and progresses to end-stage kidney disease early in life. The earlier therapy starts, the more effectively end-stage kidney disease can be delayed. Clearly then, to ensure preemptive therapy, early diagnosis is an essential prerequisite.

Methods

To provide early diagnosis, we searched for protein biomarkers (BMs) by mass spectrometry in dogs with AS stage 0. At this very early stage, we identified 74 candidate BMs. Of these, using commercial enzyme-linked immunosorbent assays (ELISAs), we evaluated 27 in dogs and 28 in children, 50 with AS and 104 healthy controls.

Results

Most BMs from blood appeared as fractions of multiple variants of the same protein, as shown by their chromatographic distribution before mass spectrometry. Blood samples showed only minor differences because ELISAs rarely detect disease-specific variants. However, in urine , several proteins, individually or in combination, were promising indicators of very early and preclinical kidney injury. The BMs with the highest sensitivity and specificity were collagen type XIII, hyaluronan binding protein 2 (HABP2), and complement C4 binding protein (C4BP).

Conclusion

We generated very strong candidate BMs by our approach of first examining preclinical AS in dogs and then validating these BMs in children at early stages of disease. These BMs might serve for screening purposes for AS before the onset of kidney damage and therefore allow preemptive therapy.

Accurate and Efficient SAXS/SANS Implementation Including Solvation Layer Effects Suitable for Molecular Simulations

Small-angle X-ray and neutron scattering (SAXS/SANS) provide valuable insights into the structure and dynamics of biomolecules in solution, complementing a wide range of structural techniques, including molecular dynamics simulations. As contrast-based methods, they are sensitive not only to structural properties but also to solvent-solute interactions. Their use in molecular dynamics simulations requires a forward model that should be as fast and accurate as possible. In this work, we demonstrate the feasibility of calculating SAXS and SANS intensities using a coarse-grained representation consisting of one bead per amino acid and three beads per nucleic acid, with form factors that can be corrected on the fly to account for solvation effects at no additional computational cost. By coupling this forward model with molecular dynamics simulations restrained with SAS data, it is possible to determine conformational ensembles or refine the structure and dynamics of proteins and nucleic acids in agreement with the experimental results. To assess the robustness of this approach, we applied it to gelsolin, for which we acquired SAXS data on its closed state, and to a UP1-microRNA complex, for which we used previously collected measurements. Our hybrid-resolution small-angle scattering (hySAS) implementation, being distributed in PLUMED, can be used with atomistic and coarse-grained simulations using diverse restraining strategies.

Clinical characterization and proteomic profiling of lean nonalcoholic fatty liver disease

Introduction

Obesity has been historically associated with nonalcoholic fatty liver disease (NAFLD), but it can also occur in lean individuals. However, limited data is available on this special group. To investigate the clinical and proteomic characteristics of lean subjects with NAFLD, and to identify potential clinical variables and plasma proteins for diagnosing NAFLD in lean individuals, we collected clinical data from a large cohort of 2,236 subjects.

Methods

Diagnosis of NAFLD relied on detecting pronounced hepatic steatosis through abdominal ultrasonography. Participants were categorized into four groups based on body mass index: overweight NAFLD, overweight control, lean NAFLD, and lean control. Plasma proteomic profiling was performed on samples from 20 subjects in each group. The lean NAFLD group was compared to both lean healthy and obese NAFLD groups across all data.

Results and discussion

The results indicated that the lean NAFLD group exhibited intermediate metabolic profiles, falling between those of the lean healthy and overweight NAFLD groups. Proteomic profiling of plasma in lean subjects with or without NAFLD revealed 45 statistically significant changes in proteins, of which 37 showed high diagnostic value (AUC > 0.7) for lean NAFLD. These potential biomarkers primarily involved lipid metabolism, the immune and complement systems, and platelet degranulation. Furthermore, AFM, GSN, CFH, HGFAC, MMP2, and MMP9 have been previously associated with NAFLD or NAFLD-related factors such as liver damage, insulin resistance, metabolic syndromes, and extracellular homeostasis. Overall, lean individuals with NAFLD exhibit distinct clinical profiles compared to overweight individuals with NAFLD. Despite having worse metabolic profiles than their healthy counterparts, lean NAFLD patients generally experience milder systemic metabolic disturbances compared to obese NAFLD patients. Additionally, the plasma proteomic profile is significantly altered in lean NAFLD, highlighting the potential of differentially expressed proteins as valuable biomarkers or therapeutic targets for diagnosing and treating NAFLD in this population.

Gelsolin, an Actin-Binding Protein: Bioinformatic Analysis and Functional Significance in Urothelial Bladder Carcinoma

The involvement of the actin-regulatory protein, gelsolin (GSN), in neoplastic transformation has been reported in different cancers including bladder cancer. However, the exact mechanism by which GSN influences bladder cancer development is not well understood. Here, we sought to reveal the functional significance of GSN in bladder cancer by undertaking a comprehensive bioinformatic analysis of TCGA datasets and through the assessment of multiple biological functions. GSN expression was knocked down in bladder cancer cell lines with two siRNA isoforms targeting GSN. Proliferation, migration, cell cycle and apoptosis assays were carried out. GSN expression, enrichment analysis, protein-protein interaction and immune infiltration analysis were verified through online TCGA tools. The data indicated that GSN expression is associated with bladder cancer proliferation, migration and enhanced cell apoptosis through regulation of NF-κB expression. GSN expression correlated with various inflammatory cells and may influence the immunity of the tumor microenvironment. Computational analysis identified several interacting partners which are associated with cancer progression and patient outcome. The present results demonstrate that GSN plays an important role in bladder cancer pathogenesis and may serve as a potential biomarker and therapeutic target for cancer therapy.

Interpreting biologically informed neural networks for enhanced proteomic biomarker discovery and pathway analysis

The incorporation of machine learning methods into proteomics workflows improves the identification of disease-relevant biomarkers and biological pathways. However, machine learning models, such as deep neural networks, typically suffer from lack of interpretability. Here, we present a deep learning approach to combine biological pathway analysis and biomarker identification to increase the interpretability of proteomics experiments. Our approach integrates a priori knowledge of the relationships between proteins and biological pathways and biological processes into sparse neural networks to create biologically informed neural networks. We employ these networks to differentiate between clinical subphenotypes of septic acute kidney injury and COVID-19, as well as acute respiratory distress syndrome of different aetiologies. To gain biological insight into the complex syndromes, we utilize feature attribution-methods to introspect the networks for the identification of proteins and pathways important for distinguishing between subtypes. The algorithms are implemented in a freely available open source Python-package ( https://github.com/InfectionMedicineProteomics/BINN ).

Decreased plasma cartilage acidic protein 1 in COVID-19

Cartilage acidic protein-1 (CRTAC1) is produced by several cell types, including Type 2 alveolar epithelial (T2AE) cells that are targeted by SARS-CoV2. Plasma CRTAC1 is known based on proteomic surveys to be low in patients with severe COVID-19. Using an ELISA, we found that patients treated for COVID-19 in an ICU almost uniformly had plasma concentrations of CRTAC1 below those of healthy controls. Magnitude of decrease in CRTAC1 distinguished COVID-19 from other causes of acute respiratory decompensation and correlated with established metrics of COVID-19 severity. CRTAC1 concentrations below those of controls were found in some patients a year after hospitalization with COVID-19, long COVID after less severe COVID-19, or chronic obstructive pulmonary disease. Decreases in CRTAC1 in severe COVID-19 correlated (r = 0.37, p = 0.0001) with decreases in CFP (properdin), which interacts with CRTAC1. Thus, decreases of CRTAC1 associated with severe COVID-19 may result from loss of production by T2AE cells or co-depletion with CFP. Determination of significance of and reasons behind decreased CRTAC1 concentration in a subset of patients with long COVID will require analysis of roles of preexisting lung disease, impact of prior acute COVID-19, age, and other confounding variables in a larger number of patients.

Gold-Induced Cytokine (GOLDIC®) Therapy in the Management of Knee Osteoarthritis: An Observational Study

BACKGROUND

Current treatment modalities for knee osteoarthritis (OA) provide symptomatic cures rather than reversing the pathology in the long term. An innovative regenerative therapy called "Gold Induced Cytokines" (GOLDIC®) was explored in various musculoskeletal diseases such as knee OA, lumbar canal stenosis, Achilles tendinopathy, and plantar fasciitis. In this study, we explored the safety and functional outcome of GOLDIC® injections in knee OA (KL grades 3 and 4) with visual analog scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores.

MATERIALS AND METHODS

A multi-center open-label observational study was carried out after screening the cases according to the inclusion criteria. A total of 106 knees in 65 patients were enrolled for four doses of 4 ml of ultrasound-guided intra-articular GOLDIC® injections every three to six days. All cases were followed up with pre- and post-VAS and WOMAC scores at an interval of four weeks, three months, six months, and one year, and the complications (including severe adverse reactions) were monitored throughout.

RESULTS

In this study, 66.1% had grade 4 OA knee (without gross varus or subluxation) and 33.8% had grade 3 OA knee. All the participants underwent the GOLDIC® treatment modality. A statistically significant difference was observed in pre- and post-procedural follow-up in VAS and WOMAC scores at one-year follow-up. There were no recorded severe adverse reactions during the entire study period. Three patients failed the treatment in one year.

CONCLUSION

The GOLDIC® procedure shows great promise as a novel method for treating moderate to severe OA of the knee, both in terms of pain and functional outcome without any severe adverse reactions, in a sustained manner and is worth exploring as a long-term treatment option.

Early pregnancy biomarker discovery study for spontaneous preterm birth

(1) OBJECTIVE: discover new candidate biomarkers for spontaneous preterm birth in early pregnancy samples. When fully clinically validated, early pregnancy biomarkers for sPTB give the possibility to intervene or monitor high-risk pregnancies more intensively through, as example, pelvic exams, ultrasound or sonographic cervical length surveillance. (2) STUDY DESIGN: Early pregnancy serum samples of eight spontaneous extreme and very preterm birth cases (<32 weeks of gestational age) without any symptoms of preeclampsia and fetal growth restriction and eight uncomplicated pregnancies were analyzed by liquid chromatography mass spectrometry (LC-MS). Thirteen proteins, which were differentially expressed according to the LC-MS data, were subsequently selected for confirmation by enzyme-linked immunosorbent assay (ELISA). (3) RESULTS: Differential expression of four candidate biomarkers was confirmed by ELISA with decreased early pregnancy levels of gelsolin and fibulin-1 and increased levels of c-reactive protein and complement C5 in the preterm birth group. (4) CONCLUSIONS: The confirmed candidate biomarkers are all to some extent related to inflammatory pathways and/or the complement system. This supports the hypothesis that both play a role in extreme and very preterm birth without any symptoms of preeclampsia and fetal growth restriction. The predictive value of complement C5, c-reactive protein, fibulin-1 and gelsolin should, therefore, be validated in another cohort with early pregnancy samples.

Entering, Linked with the Sphinx: Lysophosphatidic Acids Everywhere, All at Once, in the Oral System and Cancer

Oral health is crucial to overall health, and periodontal disease (PDD) is a chronic inflammatory disease. Over the past decade, PDD has been recognized as a significant contributor to systemic inflammation. Here, we relate our seminal work defining the role of lysophosphatidic acid (LPA) and its receptors (LPARs) in the oral system with findings and parallels relevant to cancer. We discuss the largely unexplored fine-tuning potential of LPA species for biological control of complex immune responses and suggest approaches for the areas where we believe more research should be undertaken to advance our understanding of signaling at the level of the cellular microenvironment in biological processes where LPA is a key player so we can better treat diseases such as PDD, cancer, and emerging diseases.

Engineering Therapeutics to Detoxify Hemoglobin, Heme, and Iron

Hemolysis (i.e., red blood cell lysis) can increase circulatory levels of cell-free hemoglobin (Hb) and its degradation by-products, namely heme (h) and iron (Fe). Under homeostasis, minor increases in these three hemolytic by-products (Hb/h/Fe) are rapidly scavenged and cleared by natural plasma proteins. Under certain pathophysiological conditions, scavenging systems become overwhelmed, leading to the accumulation of Hb/h/Fe in the circulation. Unfortunately, these species cause various side effects such as vasoconstriction, hypertension, and oxidative organ damage. Therefore, various therapeutics strategies are in development, ranging from supplementation with depleted plasma scavenger proteins to engineered biomimetic protein constructs capable of scavenging multiple hemolytic species. In this review, we briefly describe hemolysis and the characteristics of the major plasma-derived protein scavengers of Hb/h/Fe. Finally, we present novel engineering approaches designed to address the toxicity of these hemolytic by-products.

Presepsin: gelsolin ratio, as a promising marker of sepsis-related organ dysfunction: a prospective observational study

Introduction

We aimed to facilitate the diagnosis and prognosis of sepsis-related organ dysfunction through analyzing presepsin (PSEP) and gelsolin (GSN) levels along with a novel marker, the presepsin:gelsolin (PSEP:GSN) ratio.

Methods

Blood samples were collected from septic patients at the intensive care unit (ICU) at three time points (T1-3): T1: within 12 h after admission; T2: second day morning; T3: third day morning. Sampling points for non-septic ICU patients were T1 and T3. PSEP was measured by a chemiluminescence-based POCT method while GSN was determined by an automated immune turbidimetric assay. Data were compared with routine lab and clinical parameters. Patients were categorized by the Sepsis-3 definitions. PSEP:GSN ratio was evaluated in major sepsis-related organ dysfunctions including hemodynamic instability, respiratory insufficiency and acute kidney injury (AKI).

Results

In our single center prospective observational study, 126 patients were enrolled (23 control, 38 non-septic and 65 septic patients). In contrast to controls, significantly elevated (p < 0.001) admission PSEP:GSN ratios were found in non-septic and septic patients. Regarding 10-day mortality prediction, PSEP:GSN ratios were lower (p < 0.05) in survivors than in non-survivors during follow-up, while the prognostic performance of PSEP:GSN ratio was similar to widely used clinical scores (APACHE II, SAPS II, SOFA). PSEP:GSN ratios were also higher (p < 0.001) in patients with sepsis-related AKI than septic non-AKI patients during follow-up, especially in sepsis-related AKI patients needing renal replacement therapy. Furthermore, increasing PSEP:GSN ratios were in good agreement (p < 0.001) with the dosage and the duration of vasopressor requirement in septic patients. Moreover, PSEP:GSN ratios were markedly greater (p < 0.001) in patients with septic shock than in septic patients without shock. Compared to septic patients requiring oxygen supplementation, substantially elevated (p < 0.001) PSEP:GSN ratios were observed in septic patients with demand for mechanical ventilation, while higher PSEP:GSN ratios (p < 0.001) were also associated with extended periods of mechanical ventilation requirement in septic patients.

Conclusion

PSEP:GSN ratio could be a useful complementary marker besides the routinely used SOFA score regarding the diagnosis and short term mortality prediction of sepsis. Furthermore, the significant increase of this biomarker may also indicate the need for prolonged vasopressor or mechanical ventilation requirement of septic patients. PSEP:GSN ratio could yield valuable information regarding the extent of inflammation and the simultaneous depletion of the patient's scavenger capacity during sepsis.

Clinical trail registration

NIH U.S. National Library of Medicine, ClinicalTrails.gov. Trial identifier: NCT05060679, (https://clinicaltrials.gov/ct2/show/NCT05060679) 23.03.2022, Retrospectively registered.

Serum proteome of dogs with chronic enteropathy

BACKGROUND

Chronic enteropathy (CE) is common in dogs and can occur with multiple etiologies including food-responsive enteropathy (FRE) and idiopathic inflammatory bowel disease (IBD).

HYPOTHESIS/OBJECTIVE

To study the protein profile and pathway differences among dogs with FRE, IBD, and healthy controls using serum proteome analysis.

ANIMALS

Nine CE dogs with signs of gastrointestinal disease and histologically confirmed chronic inflammatory enteropathy and 16 healthy controls.

METHODS

A cross-sectional study with cases recruited from 2 veterinary hospitals between May 2019 and November 2020 was performed. Serum samples were analyzed using mass spectrometry-based proteomic techniques.

RESULTS

Proteomic profiles showed marked variation in relative protein abundances. Forty-five proteins were significantly (P ≤ .01) differentially expressed among the dogs with CE and controls with ≥2-fold change in abundance. The fold change of dogs with IBD normalized to controls was more pronounced for the majority of proteins than that seen in the dogs with FRE normalized to control dogs. Proteins involving reactive oxygen species, cytokine activation, acute phase response signaling, and lipid metabolism were altered in dogs with CE.

CONCLUSIONS AND CLINICAL IMPORTANCE

Cytokine alterations, acute phase response signaling, and lipid metabolism are likely involved in pathogenesis of CE. Although there are insufficient current data to justify the use of proteomic biomarkers for assessment of CE in dogs, our study identifies potential candidates.

The Antiviral Compound PSP Inhibits HIV-1 Entry via PKR-Dependent Activation in Monocytic Cells

Actin depolymerization factor (ADF) cofilin-1 is a key cytoskeleton component that serves to lessen cortical actin. HIV-1 manipulates cofilin-1 regulation as a pre- and post-entry requisite. Disruption of ADF signaling is associated with denial of entry. The unfolded protein response (UPR) marker Inositol-Requiring Enzyme-1α (IRE1α) and interferon-induced protein (IFN-IP) double-stranded RNA- activated protein kinase (PKR) are reported to overlap with actin components. In our published findings, Coriolus versicolor bioactive extract polysaccharide peptide (PSP) has demonstrated anti-HIV replicative properties in THP1 monocytic cells. However, its involvement towards viral infectivity has not been elucidated before. In the present study, we examined the roles of PKR and IRE1α in cofilin-1 phosphorylation and its HIV-1 restrictive roles in THP1. HIV-1 p24 antigen was measured through infected supernatant to determine PSP's restrictive potential. Quantitative proteomics was performed to analyze cytoskeletal and UPR regulators. PKR, IRE1α, and cofilin-1 biomarkers were measured through immunoblots. Validation of key proteome markers was done through RT-qPCR. PKR/IRE1α inhibitors were used to validate viral entry and cofilin-1 phosphorylation through Western blots. Our findings show that PSP treatment before infection leads to an overall lower infectivity. Additionally, PKR and IRE1α show to be key regulators in cofilin-1 phosphorylation and viral restriction.

Elevations of Extracellular Vesicles and Inflammatory Biomarkers in Closed Circuit SCUBA Divers

Blood-borne extracellular vesicles and inflammatory mediators were evaluated in divers using a closed circuit rebreathing apparatus and custom-mixed gases to diminish some diving risks. "Deep" divers (n = 8) dove once to mean (±SD) 102.5 ± 1.2 m of sea water (msw) for 167.3 ± 11.5 min. "Shallow" divers (n = 6) dove 3 times on day 1, and then repetitively over 7 days to 16.4 ± 3.7 msw, for 49.9 ± 11.9 min. There were statistically significant elevations of microparticles (MPs) in deep divers (day 1) and shallow divers at day 7 that expressed proteins specific to microglia, neutrophils, platelets, and endothelial cells, as well as thrombospondin (TSP)-1 and filamentous (F-) actin. Intra-MP IL-1β increased by 7.5-fold (p < 0.001) after day 1 and 41-fold (p = 0.003) at day 7. Intra-MP nitric oxide synthase-2 (NOS2) increased 17-fold (p < 0.001) after day 1 and 19-fold (p = 0.002) at day 7. Plasma gelsolin (pGSN) levels decreased by 73% (p < 0.001) in deep divers (day 1) and 37% in shallow divers by day 7. Plasma samples containing exosomes and other lipophilic particles increased from 186% to 490% among the divers but contained no IL-1β or NOS2. We conclude that diving triggers inflammatory events, even when controlling for hyperoxia, and many are not proportional to the depth of diving.

LC-MS/MS: A sensitive and selective analytical technique to detect COVID-19 protein biomarkers in the early disease stage

INTRODUCTION

The COVID-19 outbreak has put enormous pressure on the scientific community to detect infection rapidly, identify the status of disease severity, and provide an immediate vaccine/drug for the treatment. Relying on immunoassay and a real-time reverse transcription polymerase chain reaction (rRT-PCR) led to many false-negative and false-positive reports. Therefore, detecting biomarkers is an alternative and reliable approach for determining the infection, its severity, and disease progression. Recent advances in liquid chromatography and mass spectrometry (LC-MS/MS) enable the protein biomarkers even at low concentrations, thus facilitating clinicians to monitor the treatment in hospitals.

AREAS COVERED

This review highlights the role of LC-MS/MS in identifying protein biomarkers and discusses the clinically significant protein biomarkers such as Serum amyloid A, Interleukin-6, C-Reactive Protein, Lactate dehydrogenase, D-dimer, cardiac troponin, ferritin, Alanine transaminase, Aspartate transaminase, gelsolin and galectin-3-binding protein in COVID-19, and their analysis by LC-MS/MS in the early stage.

EXPERT OPINION

Clinical doctors monitor significant biomarkers to understand, stratify, and treat patients according to disease severity. Knowledge of clinically significant COVID-19 protein biomarkers is critical not only for COVID-19 caused by the coronavirus but also to prepare us for future pandemics of other diseases in detecting by LC-MS/MS at the early stages.

Plasma gelsolin levels are associated with diabetes, sex, race, and poverty

BACKGROUND

The growing epidemic of the inflammation-related metabolic disease, type 2 diabetes mellitus, presents a challenge to improve our understanding of potential mechanisms or biomarkers to prevent or better control this age-associated disease. A gelsolin isoform is secreted into the plasma as part of the extracellular actin scavenger system which serves a protective role by digesting and removing actin filaments released from damaged cells. Recent data indicate a role for decreased plasma gelsolin (pGSN) levels as a biomarker of inflammatory conditions. Extracellular vesicles (EVs), a heterogeneous group of cell-derived membranous structures involved in intercellular signaling, have been implicated in metabolic and inflammatory diseases including type 2 diabetes mellitus. We examined whether pGSN levels were associated with EV concentration and inflammatory plasma proteins in individuals with or without diabetes.

METHODS

We quantified pGSN longitudinally (n = 104) in a socioeconomically diverse cohort of middle-aged African American and White study participants with and without diabetes mellitus. Plasma gelsolin levels were assayed by ELISA. EV concentration (sub-cohort n = 40) was measured using nanoparticle tracking analysis. Inflammatory plasma proteins were assayed on the SomaScan® v4 proteomic platform.

RESULTS

pGSN levels were lower in men than women. White individuals with diabetes had significantly lower levels of pGSN compared to White individuals without diabetes and to African American individuals either with or without diabetes. For adults living below poverty, those with diabetes had lower pGSN levels than those without diabetes. Adults living above poverty had similar pGSN levels regardless of diabetes status. No correlation between EV concentrations and pGSN levels was identified (r = - 0.03; p = 0.85). Large-scale exploratory plasma protein proteomics revealed 47 proteins that significantly differed by diabetes status, 19 of which significantly correlated with pGSN levels, including adiponectin.

CONCLUSIONS

In this cohort of racially diverse individuals with and without diabetes, we found differences in pGSN levels with diabetes status, sex, race, and poverty. We also report significant associations of pGSN with the adipokine, adiponectin, and other inflammation- and diabetes-related proteins. These data provide mechanistic insights into the relationship of pGSN and diabetes.

Dietary Supplementation with Boswellia serrata, Verbascum thapsus, and Curcuma longa in Show Jumping Horses: Effects on Serum Proteome, Antioxidant Status, and Anti-Inflammatory Gene Expression

Intense exercise can cause inflammation and oxidative stress due to the production of reactive oxygen species. These pathophysiological processes are interdependent, and each one can induce the other, creating a vicious circle. A placebo-controlled blind study was carried out in show jumping horses (n. 16) to evaluate the effects of a commercial dietary supplement (Dolhorse® N.B.F. Lanes srl, Milan, Italy) containing Verbascum thapsus leaf powder (1.42%), Curcuma longa (14.280 mg/kg), and Boswellia serrata (Roxb ex Colebr) (14.280 mg/kg) extracts. Before and after 10 days of dietary supplementation, blood samples were collected to evaluate the protein levels, antioxidants, and inflammatory responses by proteomic analysis or real-time Reverse Transcriptase-Polymerase Chain Reaction (real-time RT-PCR). A total of 36 protein spots, connected to 29 proteins, were modulated by dietary supplementation, whereas real-time RT-PCR revealed a significant downregulation of proinflammatory cytokines (interleukin 1α (p < 0.05) and interleukin-6 (0.005), toll-like receptor 4 (p < 0.05), and IKBKB (p < 0.05) in supplemented sport horses. Immunoglobulin chains, gelsolin, plasminogen, vitamin D binding protein, apolipoprotein AIV, and filamin B were overexpressed, whereas haptoglobin, α-2-HS-glycoprotein, α2-macroglobulin, afamin, amine oxidase, 60S acidic ribosomal protein, and complement fragments 3, 4, and 7 were reduced. No effect was observed on the antioxidant defense systems. The present results suggest this phytotherapy may reinforce the innate immune responses, thus representing a valid adjuvant to alleviate inflammation, which is a pathophysiological process in sport horses.

Interleukin-18 and Gelsolin Are Associated with Acute Kidney Disease after Cardiac Catheterization

Patients undergoing cardiac catheterization are at high risk of post-procedure acute kidney injury (AKI) and may experience persistent renal damage after an initial insult, a state known as acute kidney disease (AKD). However, the association between AKD and urinary renal biomarkers has not yet been evaluated in this population. We enrolled 94 patients who underwent elective cardiac catheterization to investigate patterns of urinary renal biomarkers and their associations with post-procedure AKD. Serial urinary renal biomarker levels were measured during pre-procedure, early post-procedure (12–24 h), and late post-procedure (7–10 days) periods. In our investigation, 42.55% of the enrolled patients developed AKD during the late post-procedure period. While the liver-type free-fatty-acid-binding protein level increased sharply during the early post-procedure period, it returned to baseline during the late post-procedure period. In contrast, interleukin-18 (IL-18) levels increased steadily during the post-procedure period. Early post-procedure ratios of IL-18 and gelsolin (GSN) were independently associated with subsequent AKD (odds ratio (95% confidence interval), 4.742 (1.523–14.759) for IL-18 ratio, p = 0.007; 1.812 (1.027–3.198) for GSN ratio, p = 0.040). In conclusion, post-procedure AKD is common and associated with early changes in urinary IL-18 and GSN in patients undergoing cardiac catheterization.

HIV-1 Vpr Induces Degradation of Gelsolin, a Myeloid Cell-Specific Host Factor That Reduces Viral Infectivity by Inhibiting the Expression and Packaging of the HIV-1 Env Glycoprotein

Gelsolin (GSN) is a structural actin-binding protein that is known to affect actin dynamics in the cell. Using mass spectrometry, we identified GSN as a novel Vpr-interacting protein. Endogenous GSN protein was expressed at detectable levels in monocyte-derived macrophages (MDM) and in THP-1 cells, but it was undetectable at the protein level in other cell lines tested. The HIV-1 infection of MDM was associated with a reduction in GSN steady-state levels, presumably due to the Vpr-induced degradation of GSN. Indeed, the coexpression of GSN and Viral protein R (Vpr) in transiently transfected HEK293T cells resulted in the Vpr-dependent proteasomal degradation of GSN. This effect was observed for Vprs from multiple virus isolates. The overexpression of GSN in HEK293T cells had no effect on Gag expression or particle release, but it reduced the expression and packaging of the HIV-1 envelope (Env) glycoprotein and reduced viral infectivity. An analysis of the HIV-1 splicing patterns did not reveal any GSN-dependent differences, suggesting that the effect of GSN on Env expression was regulated at a posttranscriptional level. Indeed, the treatment of transfected cells with lysosomal inhibitors reversed the effect of GSN on Env stability, suggesting that GSN reduced Env expression via enhanced lysosomal degradation. Our data identify GSN as a macrophage-specific host antiviral factor that reduces the expression of HIV-1 Env. IMPORTANCE Despite dramatic progress in drug therapies, HIV-1 infection remains an incurable disease that affects millions of people worldwide. The virus establishes long-lasting reservoirs that are resistant to currently available drug treatments and allow the virus to rebound whenever drug therapy is interrupted. Macrophages are long-lived cells that are relatively insensitive to HIV-1-induced cytopathicity and thus could contribute to the viral reservoir. Here, we identified a novel host factor, gelsolin, that is expressed at high levels in macrophages and inhibits viral infectivity by modulating the expression of the HIV-1 Env glycoprotein, which is critical in the spread of an HIV-1 infection. Importantly, the viral protein Vpr induces the degradation of gelsolin and thus counteracts its antiviral activity. Our study provides significant and novel insights into HIV-1 virus-host interactions and furthers our understanding of the importance of Vpr in HIV-1 infection and pathogenesis.

Gelsolin as a Potential Clinical Biomarker in Psoriasis Vulgaris

Although discovering novel biomarkers for psoriasis is challenging, it may play an essential role in diagnosis, severity assessment, and prediction of treatment outcome and prognosis. The study was aimed to determine potential serum biomarkers of psoriasis via proteomic data analysis and clinical validity assessment. Thirty-one subjects manifested psoriasis and 19 subjects were healthy volunteers who were enrolled in the study. Protein expression was performed via two-dimensional gel electrophoresis (2-DE) using psoriasis patients' sera before and after treatment and sera of patients without psoriasis. Image analysis was then performed. Nano-scale liquid chromatography-tandem mass spectrometry (LC-MS/MS) experiments subsequently identified points showing differential expression in 2-DE image analysis. To measure levels of candidate proteins to validate results obtained from 2-DE, enzyme linked immunosorbent assay (ELISA) was then conducted. Gelsolin was identified as a potential protein through LC-MS/MS analysis and database search. Serum gelsolin levels were lower in the groups of psoriasis patients before treatment than in the control group and the group of psoriasis patients after treatment. Additionally, in subgroup analysis, serum gelsolin level was correlated with various clinical severity scores. In conclusion, low serum gelsolin levels are associated with the severity of psoriasis, proposing the potential role of gelsolin as a biomarker for severity assessment and evaluation of treatment response of psoriasis.

Plasma Gelsolin Enhances Phagocytosis of Candida auris by Human Neutrophils through Scavenger Receptor Class B

In addition to its role as an actin-depolymerizing factor in the blood, plasma gelsolin (pGSN) binds bacterial molecules and stimulates the phagocytosis of bacteria by macrophages. Here, using an in vitro system, we assessed whether pGSN could also stimulate phagocytosis of the fungal pathogen Candida auris by human neutrophils. The extraordinary ability of C. auris to evade immune responses makes it particularly challenging to eradicate in immunocompromised patients. We demonstrate that pGSN significantly enhances C. auris uptake and intracellular killing. Stimulation of phagocytosis was accompanied by decreased neutrophil extracellular trap (NET) formation and reduced secretion of proinflammatory cytokines. Gene expression studies revealed pGSN-dependent upregulation of scavenger receptor class B (SR-B). Inhibition of SR-B using sulfosuccinimidyl oleate (SSO) and block lipid transport-1 (BLT-1) decreased the ability of pGSN to enhance phagocytosis, indicating that pGSN potentiates the immune response through an SR-B-dependent pathway. These results suggest that the response of the host's immune system during C. auris infection may be enhanced by the administration of recombinant pGSN. IMPORTANCE The incidence of life-threatening multidrug-resistant Candida auris infections is rapidly growing, causing substantial economic costs due to outbreaks in hospital wards. Primary and secondary immunodeficiencies in susceptible individuals, such as those with leukemia, solid organ transplants, diabetes, and ongoing chemotherapy, often correlate with decreased plasma gelsolin concentration (hypogelsolinemia) and impairment of innate immune responses due to severe leukopenia. Immunocompromised patients are predisposed to superficial and invasive fungal infections. Morbidity caused by C. auris among immunocompromised patients can be as great as 60%. In the era of ever-growing fungal resistance in an aging society, it is critical to seek novel immunotherapies that may help combat these infections. The results reported here suggest the possibility of using pGSN as an immunomodulator of the immune response by neutrophils during C. auris infection.

Proteomic Analysis Identifies Three Reliable Biomarkers of Intestinal Inflammation in the Stools of Patients With Inflammatory Bowel Disease

BACKGROUND

Faecal biomarkers have emerged as important tools in managing of inflammatory bowel disease [IBD], which includes Crohn's disease [CD] and ulcerative colitis [UC].

AIM

To identify new biomarkers of gut inflammation in the stools of IBD patients using a proteomic approach.

METHODS

Proteomic analysis of stools was performed in patients with both active CD and CD in remission and in controls by 2-DIGE and MALDI-TOF/TOF MS. An ELISA was used to confirm results in a second cohort of IBD patients and controls.

RESULTS

2-DIGE analysis detected 70 spots in the stools of patients with active CD or patients in remission CD and in controls. MALDI-TOF/TOF MS analysis identified 21 proteins with Chymotrypsin C, Gelsolin and Rho GDP-dissociation inhibitor 2 [RhoGDI2] best correlating with the levels of intestinal inflammation. Results were confirmed in a second cohort of IBD patients and controls [57 CD, 60 UC, 31 controls]. The identified faecal markers significantly correlated with the severity of intestinal inflammation in IBD patients [SES-CD in CD, Mayo endoscopic subscore in UC] [CD; Chymotrypsin-C: r = 0.64, p < 0.001; Gelsolin: r = 0.82, p < 0.001; RhoGDI2: r = 0.64, p < 0.001; UC; Chymotrypsin-C: r = 0.76, p < 0.001; Gelsolin: r = 0.75, p < 0.001; RhoGDI2: r = 0.63, p < 0.001]. Moreover, ROC analysis showed that Gelsolin [p < 0.0002] and RhoGDI2 [p < 0.0001] in CD, and RhoGDI2 [p = 0.0004] in UC, have higher sensitivity and specificity than faecal calprotectin in discriminating between patients and controls.

CONCLUSIONS

We show for the first time that 2-DIGE is a reliable method to detect proteins in human stools. Three novel faecal biomarkers of gut inflammation have been identified that display good specificity and sensitivity for identifying IBD and significantly correlate with IBD severity.

Blood-Borne Microparticles Are an Inflammatory Stimulus in Type 2 Diabetes Mellitus

The proinflammatory state associated with diabetes mellitus (DM) remains poorly understood. We found patients with DM have 3- to 14-fold elevations of blood-borne microparticles (MPs) that bind phalloidin (Ph; Ph positive [+] MPs), indicating the presence of F-actin on their surface. We hypothesized that F-actin-coated MPs were an unrecognized cause for DM-associated proinflammatory status. Ph+MPs, but not Ph-negative MPs, activate human and murine (Mus musculus) neutrophils through biophysical attributes of F-actin and membrane expression of phosphatidylserine (PS). Neutrophils respond to Ph+MPs via a linked membrane array, including the receptor for advanced glycation end products and CD36, PS-binding membrane receptors. These proteins in conjunction with TLR4 are coupled to NO synthase 1 adaptor protein (NOS1AP). Neutrophil activation occurs because of Ph+MPs causing elevations of NF-κB and Src kinase (SrcK) via a concurrent increased association of NO synthase 2 and SrcK with NOS1AP, resulting in SrcK S-nitrosylation. We conclude that NOS1AP links PS-binding receptors with intracellular regulatory proteins. Ph+MPs are alarmins present in normal human plasma and are increased in those with DM and especially those with DM and a lower-extremity ulcer.

Selective Detection and Characterization of Small Cysteine-Containing Peptides with Cluster-Modified Nanopore Sensing

It was recently demonstrated that one can monitor ligand-induced structure fluctuations of individual thiolate-capped gold nanoclusters using resistive-pulse nanopore sensing. The magnitude of the fluctuations scales with the size of the capping ligand, and it was later shown one can observe ligand exchange in this nanopore setup. We expand on these results by exploring the different types of current fluctuations associated with peptide ligands attaching to tiopronin-capped gold nanoclusters. We show here that the fluctuations can be used to identify the attaching peptide through either the magnitude of the peptide-induced current jumps or the onset of high-frequency current fluctuations. Importantly, the peptide attachment process requires that the peptide contains a cysteine residue. This suggests that nanopore-based monitoring of peptide attachments with thiolate-capped clusters could provide a means for selective detection of cysteine-containing peptides. Finally, we demonstrate the cluster-based protocol with various peptide mixtures to show that one can identify more than one cysteine-containing peptide in a mixture.

Exosomal Plasma Gelsolin Is an Immunosuppressive Mediator in the Ovarian Tumor Microenvironment and a Determinant of Chemoresistance

Ovarian Cancer (OVCA) is the most fatal gynecologic cancer and has a 5-year survival rate less than 45%. This is mainly due to late diagnosis and drug resistance. Overexpression of plasma gelsolin (pGSN) is key contributing factor to OVCA chemoresistance and immunosuppression. Gelsolin (GSN) is a multifunctional protein that regulates the activity of actin filaments by cleavage, capping, and nucleation. Generally, it plays an important role in cytoskeletal remodeling. GSN has three isoforms: cytosolic GSN, plasma GSN (pGSN), and gelsolin-3. Exosomes containing pGSN are released and contribute to the progression of OVCA. This review describes how pGSN overexpression inhibits chemotherapy-induced apoptosis and triggers positive feedback loops of pGSN expression. It also describes the mechanisms by which exosomal pGSN promotes apoptosis and dysfunction in tumor-killing immune cells. A discussion on the potential of pGSN as a prognostic, diagnostic, and therapeutic marker is also presented herein.

Plasma Extracellular Vesicles Play a Role in Immune System Modulation in Minimal Hepatic Encephalopathy

Minimal hepatic encephalopathy (MHE) is associated with changes in the immune system including an increased pro-inflammatory environment and altered differentiation of CD4+ T lymphocytes. The mechanisms remain unknown. Changes in extracellular vesicle (EV) cargo including proteins and miRNAs could play a main role as mediators of immune system changes associated with MHE. The aim was to assess whether plasma EVs from MHE patients played a role in inducing the pro-inflammatory environment and altered differentiation of CD4+ T lymphocyte subtypes in MHE patients. We characterized the miRNA and protein cargo of plasma EVs from 50 cirrhotic patients (27 without and 23 with MHE) and 24 controls. CD4+ T cells from the controls were cultured with plasma EVs from the three groups of study, and the cytokine release and differentiation to CD4+ T-cell subtypes were assessed. Plasma EVs from MHE patients had altered miRNA and protein contents, and were enriched in inflammatory factors compared to the controls and patients without MHE. EVs from MHE patients modulated the expression of pro-inflammatory IL-17, IL-21, and TNF-α and anti-inflammatory TGF-β in cultured CD4+ T lymphocytes, and increased the proportion of Th follicular and Treg cells and the activation of Th17 cells. In conclusion, plasma EVs could play an important role in the induction of immune changes observed in MHE.

Emerging roles of plasma gelsolin in tumorigenesis and modulating the tumor microenvironment

The protein expression of gelsolin, an actin scavenger controlling cytoskeletal remodeling, cell morphology, differentiation, movement, and apoptosis, has been found to be significantly decreased in several pathological conditions including neurodegenerative diseases, inflammatory disorders, and cancers. Its extracellular isoform, called plasma gelsolin (pGSN), is one of the most abundant plasma proteins in the circulation, and has emerged as a novel diagnostic biomarker for early disease detection. Current evidence reveals that gelsolin can function as either an oncoprotein or a tumor suppressor depending on the carcinoma type. Interestingly, recent studies have shown that pGSN is also involved in immunomodulation, revealing the multifunctional roles of pGSN in tumor progression. In this review, we discuss the current knowledge focusing on the roles of gelsolin in inflammation and wound healing, cancers, and tumor microenvironment. Future prospects of pGSN related studies and clinical application are also addressed.

Adjunctive Recombinant Human Plasma Gelsolin for Severe Coronavirus Disease 2019 Pneumonia

Background

Excessive inflammation contributes to the morbidity and mortality of severe coronavirus disease 2019 (COVID-19) pneumonia. Recombinant human plasma gelsolin (rhu-pGSN) improves disease outcomes in diverse experimental models of infectious and noninfectious inflammation.

Methods

In a blinded, randomized study, 61 subjects with documented COVID-19 pneumonia having a World Health Organization (WHO) Severity Score of 4 to 6 and evidence of a hyperinflammatory state were treated with standard care and either adjunctive rhu-pGSN 12 mg/kg or an equal volume of saline placebo given intravenously at entry, 12 hours, and 36 hours. The prespecified coprimary outcomes were survival without major respiratory, hemodynamic, or renal support on Day 14 and the incidence of serious adverse events (SAEs) during the 90-day study period.

Results

All subjects receiving ≥1 dose of study drug were analyzed. Fifty-four of 61 subjects (88.5%) were WHO severity level 4 at entry. The proportions of subjects alive without support on Day 14 were 25 of 30 rhu-pGSN recipients (83.3%) and 27 of 31 placebo recipients (87.1%). Over the duration of the study, WHO Severity Scores improved similarly in both treatment groups. No statistically significant differences were observed between treatment groups at any time point examined. Two subjects died in each group. Numerically fewer subjects in the rhu-pGSN group had SAEs (5 subjects; 16.7%) or ≥ Grade 3 adverse events (5 subjects; 16.7%) than in the placebo group (8 subjects [25.8%] and 9 subjects [29.0%], respectively), mostly involving the lungs. Three rhu-pGSN recipients (10.0%) were intubated compared to 6 placebo recipients (19.4%).

Conclusions

Overall, subjects in this study did well irrespective of treatment arm. When added to dexamethasone and remdesivir, no definitive benefit was demonstrated for rhu-pGSN relative to placebo. Safety signals were not identified after the administration of 3 doses of 12 mg/kg rhu-pGSN over 36 hours. The frequencies of SAEs and intubation were numerically fewer in the rhu-pGSN group compared with placebo.

GOLDIC therapy in degenerative lumbar spinal stenosis: randomized, controlled trial

Aim: Comparison of the efficacy of conservative treatment methods: epidural GOLDIC serum, epidural steroid injections, manual therapy. Materials & methods: A randomized, controlled trial. Three groups, each containing 30 patients. GOLDIC or steroid injections (dexamethasone) epidural versus manual therapy. Assessment: initial assessment and 4 (T1), 12 (T2) and 24 (T3) weeks after the last intervention. Primary outcomes: Pain intensity in numeric rating scale, Oswestry disability index, Zurich claudication questionnaire, EQ-5D-5L questionnaire. Results: GOLDIC has shown the highest mean differences and number of cases with minimal important difference among groups for every primary outcome. Conclusion: GOLDIC therapy could be a new option for the nonoperative, symptomatic treatment of degenerative lumbar spinal stenosis and is not inferior to epidural steroid injections and manual therapy.

Gelsolin as a Potential Biomarker for Endoscopic Activity and Mucosal Healing in Ulcerative Colitis

The therapeutic goal in ulcerative colitis is mucosal healing, which requires improved non-invasive biomarkers to evaluate disease activity. Gelsolin is associated with several autoimmune diseases, and here, we aimed to analyze its usefulness as a serological biomarker for clinical and endoscopic activities in ulcerative colitis. Patients with ulcerative colitis (n = 138) who had undergone blood tests and colonoscopy were included. Serum gelsolin was measured using enzyme-linked immunosorbent assay, and correlation between the gelsolin level and clinical and endoscopic activities was examined. The serum gelsolin level in patients with ulcerative colitis was significantly lower than that in healthy subjects, and it decreased in proportion to increasing Mayo score and Mayo endoscopic subscore. The area under the curve for correlation between clinical and endoscopic remission and serum gelsolin level was higher than that for C-reactive protein. Furthermore, in C-reactive protein-negative patients, the serum gelsolin level was lower in the active phase than in remission. Our findings indicate that the serum gelsolin level correlates with clinical and endoscopic activities in ulcerative colitis, has a higher sensitivity and specificity than C-reactive protein, and can detect mucosal healing, suggesting that gelsolin can be used as a biomarker for ulcerative colitis.

Proteomic and Biochemical Analysis of Extracellular Vesicles Isolated from Blood Serum of Patients with Melanoma

Background: Malignant melanoma is the most serious type of skin cancer with the highest mortality rate. Extracellular vesicles (EVs) have potential as new tumor markers that could be used as diagnostic and prognostic markers for early detection of melanoma. Methods: EVs were purified from the blood serum of melanoma patients using two methods—ultracentrifugation and PEG precipitation—and analyzed by mass spectrometry and immunoblot. Results: We identified a total of 585 unique proteins; 334 proteins were detected in PEG-precipitated samples and 515 in UC-purified EVs. EVs purified from patients varied in their size and concentration in different individuals. EVs obtained from stage II and III patients were, on average, smaller and more abundant than others. Detailed analysis of three potential biomarkers—SERPINA3, LGALS3BP, and gelsolin—revealed that the expression of SERPINA3 and LGALS3BP was higher in melanoma patients than healthy controls, while gelsolin exhibited higher expression in healthy controls. Conclusion: We suggest that all three proteins might have potential to be used as biomarkers, but a number of issues, such as purification of EVs, standardization, and validation of methods suitable for everyday clinical settings, still need to be addressed.

Integrin-linked kinase (ILK): the known vs. the unknown and perspectives

Integrin-linked kinase (ILK) is a multifunctional molecular actor in cell-matrix interactions, cell adhesion, and anchorage-dependent cell growth. It combines functions of a signal transductor and a scaffold protein through its interaction with integrins, then facilitating further protein recruitment within the ILK-PINCH-Parvin complex. ILK is involved in crucial cellular processes including proliferation, survival, differentiation, migration, invasion, and angiogenesis, which reflects on systemic changes in the kidney, heart, muscle, skin, and vascular system, also during the embryonal development. Dysfunction of ILK underlies the pathogenesis of various diseases, including the pro-oncogenic activity in tumorigenesis. ILK localizes mostly to the cell membrane and remains an important component of focal adhesion. We do know much about ILK but a lot still remains either uncovered or unclear. Although it was initially classified as a serine/threonine-protein kinase, its catalytical activity is now questioned due to structural and functional issues, leaving the exact molecular mechanism of signal transduction by ILK unsolved. While it is known that the three isoforms of ILK vary in length, the presence of crucial domains, and modification sites, most of the research tends to focus on the main isoform of this protein while the issue of functional differences of ILK2 and ILK3 still awaits clarification. The activity of ILK is regulated on the transcriptional, protein, and post-transcriptional levels. The crucial role of phosphorylation and ubiquitylation has been investigated, but the functions of the vast majority of modifications are still unknown. In the light of all those open issues, here we present an extensive literature survey covering a wide spectrum of latest findings as well as a past-to-present view on controversies regarding ILK, finishing with pointing out some open questions to be resolved by further research.

Regulation of Mitochondrial Function by the Actin Cytoskeleton

The regulatory role of actin cytoskeleton on mitochondrial function is a growing research field, but the underlying molecular mechanisms remain poorly understood. Specific actin-binding proteins (ABPs), such as Gelsolin, have also been shown to participate in the pathophysiology of mitochondrial OXPHOS disorders through yet to be defined mechanisms. In this mini-review, we will summarize the experimental evidence supporting the fundamental roles of actin cytoskeleton and ABPs on mitochondrial trafficking, dynamics, biogenesis, metabolism and apoptosis, with a particular focus on Gelsolin involvement in mitochondrial disorders. The functional interplay between the actin cytoskeleton, ABPs and mitochondrial membranes for the regulation of cellular homeostasis thus emerges as a new exciting field for future research and therapeutic approaches.

Implication of plasma gelsolin in systemic lupus erythematosus patients

Background

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder with more than one organ involvement. Kidney is the foremost commonly affected one. Gelsolin is a protein that induces depolymerization of actin filaments thus preventing downstream stimulation of inflammatory reactions. The aim of this work was to detect the relation of plasma gelsolin to SLE disease activity and severity indices in order to find out if plasma gelsolin could be used as a biomarker of the disease. This study was conducted on 50 SLE female patients and 30 matched control. SLE disease activity Index (SLEDAI) and SLE damage index (SDI) were assessed. All lupus nephritis (LN) patients were subjected to an ultrasound-guided kidney biopsy. Plasma gelsolin level was measured.

Results

The mean age of the patients was 38.5 ± 6.3 years (26–51 years) with median disease duration of 5 (3–9.3) years. Eighteen patients had LN, 11 had cardiac manifestations and 12 had chest manifestations. The mean SLEDAI was 13.1 ± 4.5 (4–22) and the median SDI was 2 (1–3). Plasma gelsolin level was significantly lower in SLE patients (74.9 mg/l; 57.5–98.8 mg/l) compared to control (801.5 mg/l; 225–1008.3 mg/l) (p < 0.001). There were significant negative correlations of gelsolin levels with anti-ds DNA (r = − 0.63, p < 0.001), SLEDAI (r = − 0.79, p < 0.001), and SDI (r = − 0.74, p = 0.001). Plasma gelsolin level was significantly lower in SLE patients with high/very high activity grades compared to those with low and moderate (p = 0.007 and p < 0.001 respectively). A gelsolin level of ≤ 78.95 mg/l significantly predicted renal affection (p < 0.001), with a sensitivity of 100%, specificity 71.9%, and a positive predictive value 66.7%.

Conclusion

A decreased gelsolin level is associated with disease activity in SLE patients. Plasma gelsolin was well related to disease activity and severity with a high predictive value for renal affection comparable to anti-ds DNA titre. Plasma gelsolin is a potentially important predictive biomarker for SLE and LN.

Hypogelsolinemia and Decrease in Blood Plasma Sphingosine-1-Phosphate in Patients Diagnosed with Severe Acute Pancreatitis

BACKGROUND

Acute pancreatitis (AP) is a frequent hospitalization cause of patients suffering from gastrointestinal disorders. Gelsolin has an ability to bind bioactive lipids including different sphingolipids engaged in inflammatory response. Importantly, hypogelsolinemia was observed in patients with different states of acute and chronic inflammation.

AIMS

The aim of the present study was to assess the interplay of blood plasma gelsolin and blood plasma sphingosine-1-phosphate (S1P) concentration in patients diagnosed with acute pancreatitis.

MATERIALS AND METHODS

To assess the concentration of gelsolin and S1P, immunoblotting and HPLC technique were employed, respectively. Additionally, the concentrations of amylase, lipase, C-reactive protein (CRP), procalcitonin (PCT) and the number of white blood cells (WBC) and platelet (PLT) were recorded.

RESULTS

We found that both pGSN and S1P concentrations in the plasma of the AP patients were significantly lower (pGSN ~ 15-165 mg/L; S1P ~ 100-360 pmol/mL) when compared to the levels of pGSN and S1P in a control group (pGSN ~ 130-240 mg/L; S1P ~ 260-400 pmol/mL). Additionally, higher concentrations of CRP, WBC, amylase and lipase were associated with low level of gelsolin in the blood of AP patients. No correlations between the level of PCT and PLT with gelsolin concentration were noticed.

CONCLUSION

Plasma gelsolin and S1P levels decrease during severe acute pancreatitis. Simultaneous assessment of pGSN and S1P can be useful in development of more accurate diagnostic strategies for patients with severe acute pancreatitis.

Sequence edition of single domains modulates the final immune and antimicrobial potential of a new generation of multidomain recombinant proteins

Combining several innate immune peptides into a single recombinant antimicrobial and immunomodulatory polypeptide has been recently demonstrated. However, the versatility of the multidomain design, the role that each domain plays and how the sequence edition of the different domains affects their final protein activity is unknown. Parental multidomain antimicrobial and immunomodulatory protein JAMF1 and several protein variants (JAMF1.2, JAMF2 and AM2) have been designed and recombinantly produced to explore how the tuning of domain sequences affects their immunomodulatory potential in epithelial cells and their antimicrobial capacity against Gram-positive and Gram-negative bacteria. The replacement of the sequence of defensin HD5 and phospholipase sPLA2 by shorter active fragments of both peptides improves the final immunomodulatory (IL-8 secretion) and antimicrobial function of the multidomain protein against antimicrobial-resistant Klebsiella pneumoniae and Enterococcus spp. Further, the presence of Jun and Fos leucine zippers in multidomain proteins is crucial in preventing toxic effects on producer cells. The generation of antimicrobial proteins based on multidomain polypeptides allows specific immunomodulatory and antimicrobial functions, which can be easily edited by modifying of each domain sequence.

The Pathophysiologic Role of Gelsolin in Chronic Kidney Disease: Focus on Podocytes

Chronic kidney disease (CKD) is normally related to proteinuria, a common finding in a compromised glomerular filtration barrier (GFB). GFB is a structure composed of glomerular endothelial cells, the basement membrane, and the podocytes. CKD with podocyte damage may be associated with actin cytoskeleton reorganization, resulting in podocyte effacement. Gelsolin plays a critical role in several diseases, including cardiovascular diseases and cancer. Our current study aimed to determine the connection between gelsolin and podocyte, and thus the mechanism underlying podocyte injury in CKD. Experiments were carried out on Drosophila to demonstrate whether gelsolin had a physiological role in maintaining podocyte. Furthermore, the survival rate of gelsolin-knocked down Drosophila larvae was extensively reduced after AgNO₃ exposure. Secondly, the in vitro podocytes treated with puromycin aminonucleoside (PAN) enhanced the gelsolin protein expression, as well as small GTPase RhoA and Rac1, which also regulated actin dynamic expression incrementally with the PAN concentrations. Thirdly, we further demonstrated in vivo that GSN was highly expressed inside the glomeruli with mitochondrial dysfunction in a CKD mouse model. Our findings suggest that an excess of gelsolin may contribute to podocytes damage in glomeruli.

Proteomic Profiling of Plasma-Derived Biomarkers in Patients with Bladder Cancer: A Step towards Clinical Translation

Background: Bladder cancer is a life-threatening disease and a major cause of cancer-associated complications. The main challenges confronted during the clinical management of bladder cancer are associated with recurrence and disease progression to the muscle-invasive phenotype. Improved early detection of the disease is of paramount importance to prevent disease progression and improve survival. Hence, novel clinically applicable biomarkers for early detection are warranted. Methods: In the current study, a comparative proteomic approach was undertaken using plasma samples to identify protein biomarkers associated with the muscle-invasive phenotype of bladder carcinoma. Isolated plasma proteins were depleted, DIGE-labeled, then subjected to conventional 2D electrophoresis followed by mass spectrometry for identification of differentially expressed proteins. Western blot was used for data validation. Results: Fourteen differentially expressed proteins with statistically significant changes in abundance between the cancer group and control group were identified. Three differentially expressed proteins were selected for validation, among which apolipoprotein A1 exhibited high specificity and sensitivity (AUC = 0.906). Ingenuity pathway analysis identified IFN-γ and TNF-α as the main signaling hub for the differentially regulated proteins. Conclusion: Our findings provide additional insight into understanding bladder cancer pathogenesis. Our data identified potential non-invasive plasma-derived biomarker proteins that merit additional investigation to validate its clinical usefulness to prevent bladder cancer progression.

Circulating Actin-Binding Proteins in Laryngeal Cancer: Its Relationship with Circulating Tumor Cells and Cells of the Immune System

We previously exposed the role of actin-binding proteins (ABPs) in cancer development and progression. In this paper, we studied the relationship between circulating ABPs and the number of ABP-expressing leukocytes and circulating tumor cells (CTCs) in patients with highly aggressive laryngeal squamous cell carcinoma (LSCC). The levels of cofilin (CFL1), profilin (PFN1), ezrin (EZR), fascin (FSCN1), and adenylate cyclase-associated protein 1 (CAP1) were determined using enzyme immunoassay. The ABP expression by the cellular pools was analyzed by flow cytometry. The highest levels of FSCN1 and EZR were found in the blood serum of LSCC patients. There was a difference in ABP expression between the pools of leukocytes and CTCs. Leukocytes were mainly represented by CAP1+ and FSCN1+ pools, and CTCs contained CAP1+, FSCN1+, and EZR+ cells. The serum FSCN1 level correlated with the number of FSCN1-containing and CFL1-containing leukocytes. Thus, the level of circulating EZR is likely related to its expression in CTCs. The levels of CFL1 and PFN1 are likely to be supported by the expression of these proteins by leukocytes. Both CTCs and leukocytes can be a source of FSCN1 and CAP1 in blood serum. The results suggest that serum proteins can be produced by various cells, thus indicating both cancer development and the response of the immune system to this process.

Proteomics and its applications in breast cancer

Breast cancer is an individually unique, multi-faceted and chameleonic disease, an eternal challenge for the new era of high-integrated precision diagnostic and personalized oncomedicine. Besides traditional single-omics fields (such as genomics, epigenomics, transcriptomics and metabolomics) and multi-omics contributions (proteogenomics, proteotranscriptomics or reproductomics), several new "-omics" approaches and exciting proteomics subfields are contributing to basic and advanced understanding of these "multiple diseases termed breast cancer": phenomics/cellomics, connectomics and interactomics, secretomics, matrisomics, exosomics, angiomics, chaperomics and epichaperomics, phosphoproteomics, ubiquitinomics, metalloproteomics, terminomics, degradomics and metadegradomics, adhesomics, stressomics, microbiomics, immunomics, salivaomics, materiomics and other biomics. Throughout the extremely complex neoplastic process, a Breast Cancer Cell Continuum Concept (BCCCC) has been modeled in this review as a spatio-temporal and holistic approach, as long as the breast cancer represents a complex cascade comprising successively integrated populations of heterogeneous tumor and cancer-associated cells, that reflect the carcinoma's progression from a "driving mutation" and formation of the breast primary tumor, toward the distant secondary tumors in different tissues and organs, via circulating tumor cell populations. This BCCCC is widely sustained by a Breast Cancer Proteomic Continuum Concept (BCPCC), where each phenotype of neoplastic and tumor-associated cells is characterized by a changing and adaptive proteomic profile detected in solid and liquid minimal invasive biopsies by complex proteomics approaches. Such a profile is created, beginning with the proteomic landscape of different neoplastic cell populations and cancer-associated cells, followed by subsequent analysis of protein biomarkers involved in epithelial-mesenchymal transition and intravasation, circulating tumor cell proteomics, and, finally, by protein biomarkers that highlight the extravasation and distant metastatic invasion. Proteomics technologies are producing important data in breast cancer diagnostic, prognostic, and predictive biomarkers discovery and validation, are detecting genetic aberrations at the proteome level, describing functional and regulatory pathways and emphasizing specific protein and peptide profiles in human tissues, biological fluids, cell lines and animal models. Also, proteomics can identify different breast cancer subtypes and specific protein and proteoform expression, can assess the efficacy of cancer therapies at cellular and tissular level and can even identify new therapeutic target proteins in clinical studies.

IceR improves proteome coverage and data completeness in global and single-cell proteomics

Label-free proteomics by data-dependent acquisition enables the unbiased quantification of thousands of proteins, however it notoriously suffers from high rates of missing values, thus prohibiting consistent protein quantification across large sample cohorts. To solve this, we here present IceR (Ion current extraction Re-quantification), an efficient and user-friendly quantification workflow that combines high identification rates of data-dependent acquisition with low missing value rates similar to data-independent acquisition. Specifically, IceR uses ion current information for a hybrid peptide identification propagation approach with superior quantification precision, accuracy, reliability and data completeness compared to other quantitative workflows. Applied to plasma and single-cell proteomics data, IceR enhanced the number of reliably quantified proteins, improved discriminability between single-cell populations, and allowed reconstruction of a developmental trajectory. IceR will be useful to improve performance of large scale global as well as low-input proteomics applications, facilitated by its availability as an easy-to-use R-package.

Quorum Sensing by Gelsolin Regulates Programmed Cell Death 4 Expression and a Density-Dependent Phenotype in Macrophages

Quorum-sensing mechanisms that sense the density of immune cells at the site of inflammation to initiate inflammation resolution have recently been demonstrated as a major determinant of the inflammatory response. We observed a density-dependent increase in expression of the inflammatory tumor suppressor protein programmed cell death 4 (PDCD4) in mouse macrophage cells. Conditioned medium from high-density cells upregulated PDCD4 expression, revealing the presence of a secreted factor(s) acting as a macrophage quorum sensor. Secreted gelsolin (GSN) was identified as the quorum-sensing autoinducer. Alteration of GSN levels changed PDCD4 expression and the density-dependent phenotype of cells. LPS induced the expression of microRNA miR-21, which downregulated both GSN and PDCD4 expression, and reversed the high-density phenotype. The high-density phenotype was correlated with an anti-inflammatory gene expression program, which was counteracted by inflammatory stimulus. Together, our observations establish the miR-21-GSN-PDCD4 regulatory network as a crucial mediator of a macrophage quorum-sensing mechanism for the control of inflammatory responses.

Gelsolin Contributes to the Motility of A375 Melanoma Cells and This Activity Is Mediated by the Fibrous Extracellular Matrix Protein Profile

Skin melanocytes reside on the basement membrane (BM), which is mainly composed of laminin, collagen type IV, and proteoglycans. For melanoma cells, in order to invade into the skin, melanocytes must cross the BM. It has been reported that changes in the composition of the BM accompany melanocytes tumorigenesis. Previously, we reported high gelsolin (GSN)-an actin-binding protein-levels in melanoma cell lines and GSN's importance for migration of A375 cells. Here we investigate whether melanoma cells migrate differently depending on the type of fibrous extracellular matrix protein. We obtained A375 melanoma cells deprived of GSN synthesis and tested their migratory properties on laminin, collagens type I and IV, fibronectin, and Matrigel, which resembles the skin's BM. We applied confocal and structured illuminated microscopy (SIM), gelatin degradation, and diverse motility assays to assess GSN's influence on parameters associated with cells' ability to protrude. We show that GSN is important for melanoma cell migration, predominantly on laminin, which is one of the main components of the skin's BM.

Aircraft noise exposure drives the activation of white blood cells and induces microvascular dysfunction in mice

Epidemiological studies showed that traffic noise has a dose-dependent association with increased cardiovascular morbidity and mortality. Whether microvascular dysfunction contributes significantly to the cardiovascular health effects by noise exposure remains to be established. The connection of inflammation and immune cell interaction with microvascular damage and functional impairment is also not well characterized. Male C57BL/6J mice or gp91phox^−/y mice with genetic deletion of the phagocytic NADPH oxidase catalytic subunit (gp91phox or NOX-2) were used at the age of 8 weeks, randomly instrumented with dorsal skinfold chambers and exposed or not exposed to aircraft noise for 4 days. Proteomic analysis (using mass spectrometry) revealed a pro-inflammatory phenotype induced by noise exposure that was less pronounced in noise-exposed gp91phox^−/y mice. Using in vivo fluorescence microscopy, we found a higher number of adhesive leukocytes in noise-exposed wild type mice. Dorsal microvascular diameter (by trend), red blood cell velocity, and segmental blood flow were also decreased by noise exposure indicating microvascular constriction. All adverse effects on functional parameters were normalized or improved at least by trend in noise-exposed gp91phox^−/y mice. Noise exposure also induced endothelial dysfunction in cerebral microvessels, which was associated with higher oxidative stress burden and inflammation, as measured using video microscopy. We here establish a link between a pro-inflammatory phenotype of plasma, activation of circulating leukocytes and microvascular dysfunction in mice exposed to aircraft noise. The phagocytic NADPH oxidase was identified as a central player in the underlying pathophysiological mechanisms.

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Noise exposure induces a pro-thrombo-inflammatory phenotype in mouse plasma.

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Aircraft noise increases leukocyte-endothelium interactions in dorsal microvessels.

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Noise decreases segmental blood flow/red blood cell velocity in dorsal microvessels.

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Noise increases cerebral microvascular dysfunction and oxidative stress.

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Nox2 deficiency (gp91phox^-/y) improves noise-induced adverse effects.

Bench to Bedside: Proteomic Biomarker Analysis of Cerebrospinal Fluid in Patients With Spondylomyelopathy

Establishing proteomic biomarkers is critical for characterizing disease pathophysiology, identifying genetic risk factors, and predicting clinical outcomes. However, diseases like cervical spondylomyelopathy have not been actively characterized for molecular significance, leading to questions regarding the pathology's molecular mechanisms. Namely, spondylomyelopathy is a degenerative spinal disease that leads to compression and neurologic deficits in the spinal cord. Analyzing a patient's cerebrospinal fluid (CSF) has been well-known for revealing biomarkers that are associated with diseases of the central nervous system. Therefore, in this review, we will formulate a proteomic profile of spondylomyelopathy through a molecular analysis of the CSF. The proteins found to be upregulated in the CSF include vitamin D-binding protein (VDBP), gelsolin, creatine kinase B-type (CK-BB), and angiotensinogen. Meanwhile, the proteins that were downregulated include pigment epithelium-derived factor (PEDF), prostaglandin-H2 D-isomerase (PGH2), apolipoprotein E (APOE), and clusterin. The cellular functions of these proteins are discussed, along with their relevance in manifesting spondylomyelopathy. However, further studies are warranted, as a lack of human studies is a major limiting factor. Nevertheless, based on the continued progression of the proteomic profile of spondylomyelopathy, new targets can be assessed as candidates for future therapeutic intervention.

Serum biomarker discovery related to pathogenesis in acute coronary syndrome by proteomic approach

Acute coronary syndrome (ACS) results from inadequate supply of blood flow from the coronary arteries to the heart or ischemia. ACS has an extremely high morbidity and mortality. The levels of biomarkers currently used for detection of ACS also increase in response to myocardial necrosis and other diseases and are not elevated immediately after symptoms appear, thus limiting their diagnostic capacity. Therefore, we aimed to discover new ACS diagnostic biomarkers with high sensitivity and specificity that are specifically related to ACS pathogenesis. Sera from 50 patients with ACS and healthy controls (discovery cohort) each were analyzed using mass spectrometry (MS) to identify differentially expressed proteins, and protein candidates were evaluated as ACS biomarkers in 120 people in each group (validation cohort). α-1-acid glycoprotein 1 (AGP1), complement C5 (C5), leucine-rich α-2-glycoprotein (LRG), and vitronectin (VN) were identified as biomarkers whose levels increase and gelsolin (GSN) as a biomarker whose levels decrease in patients with ACS. We concluded that these biomarkers are associated with the pathogenesis of ACS and can predict the onset of ACS prior to the appearance of necrotic biomarkers.