The value of decreased plasma gelsolin levels in patients with systemic lupus erythematosus and rheumatoid arthritis in diagnosis and disease activity evaluation

Rescue of mitochondrial dysfunction through alteration of extracellular matrix composition in barth syndrome cardiac fibroblasts

Fibroblast-ECM (dys)regulation is associated with a plethora of diseases. The ECM acts as a reservoir of inflammatory factors and cytokines that mediate molecular mechanisms within cardiac cell populations. The role of ECM-mitochondria crosstalk in the development and progression of cardiac disorders remains uncertain. We evaluated the influence of ECM produced by stromal cells from patients with the mitochondrial cardiomyopathy (Barth syndrome, BTHS) and unaffected healthy controls on cardiac fibroblast (CF) metabolic function. To do this, cell-derived matrices CDMs were generated from BTHS and healthy human pluripotent stem cell-derived CFs (hPSC-CF) and used as cell culture substrates. BTHS CDMs negatively impacted the mitochondrial function of healthy hPSC-CFs while healthy CDMs improved mitochondrial function in BTHS hPSC-CFs. Mass spectrometry comparisons identified 5 matrisome proteins differentially expressed in BTHS compared to healthy CDM. Our results highlight a key role for the ECM in disease through its impact on mitochondrial function.

Gelsolin alleviates rheumatoid arthritis by negatively regulating NLRP3 inflammasome activation

Despite numerous biomarkers being proposed for rheumatoid arthritis (RA), a gap remains in our understanding of their mechanisms of action. In this study, we discovered a novel role for gelsolin (GSN), an actin-binding protein whose levels are notably reduced in the plasma of RA patients. We elucidated that GSN is a key regulator of NLRP3 inflammasome activation in macrophages, providing a plausible explanation for the decreased secretion of GSN in RA patients. We found that GSN interacts with NLRP3 in LPS-primed macrophages, hence modulating the formation of the NLRP3 inflammasome complex. Reducing GSN expression significantly enhanced NLRP3 inflammasome activation. GSN impeded NLRP3 translocation to the mitochondria; it contributed to the maintenance of intracellular calcium equilibrium and mitochondrial stability. This maintenance is crucial for controlling the inflammatory response associated with RA. Furthermore, the exacerbation of arthritic symptoms in GSN-deficient mice indicates the potential of GSN as both a diagnostic biomarker and a therapeutic target. Moreover, not limited to RA models, GSN has demonstrated a protective function in diverse disease models associated with the NLRP3 inflammasome. Myeloid cell-specific GSN-knockout mice exhibited aggravated inflammatory responses in models of MSU-induced peritonitis, folic acid-induced acute tubular necrosis, and LPS-induced sepsis. These findings suggest novel therapeutic approaches that modulate GSN activity, offering promise for more effective management of RA and a broader spectrum of inflammatory conditions.

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.

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.

Glycosphingolipid Levels in Urine Extracellular Vesicles Enhance Prediction of Therapeutic Response in Lupus Nephritis

The development of nephritis increases the risk of morbidity and mortality in systemic lupus erythematosus (SLE) patients. While standard induction therapies, such as mycophenolate mofetil (MMF) induce clinical remission (i.e., complete response) in approximately 50% of SLE patients with nephritis, many patients fail to respond. Therapeutic response is often not assessed until 6-12 months after beginning treatment. Those patients that fail to respond to treatment continue to accumulate organ damage, thus, there is a critical need to predict which patients will fail therapy before beginning treatment, allowing physicians to optimize therapy. Our previous studies demonstrated elevated urine, but not serum, glycosphingolipids (GSLs) in SLE patients with nephritis compared to SLE patients without nephritis, suggesting the urine GSLs were derived from the kidney. In this study, we measured the GSLs hexosylceramide and lactosylceramide in extracellular vesicles isolated from longitudinal urine samples of LN patients that were treated with MMF for 12 months. GSL levels were significantly elevated in the baseline samples (prior to treatment) of non-responders compared to complete responders. While a few other proteins measured in the whole urine were higher in non-responders at baseline, only GSLs demonstrated a significant ability to discriminate treatment response in lupus nephritis patients.

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.

Safety and Pharmacokinetics of Recombinant Human Plasma Gelsolin in Patients Hospitalized for Nonsevere Community-Acquired Pneumonia

There remains an unmet need to address the substantial morbidity and mortality associated with severe community-acquired pneumonia (sCAP). Recombinant human plasma gelsolin (rhu-pGSN) improves disease outcomes in diverse animal models of infectious and noninfectious inflammation. This blinded dose-escalation safety study involved non-intensive care unit (ICU) patients admitted for mild CAP and randomized 3:1 to receive adjunctive rhu-pGSN or placebo intravenously. Thirty-three subjects were treated: 8 in the single-dose phase and 25 in the multidose phase. For the single-dose phase, rhu-pGSN at 6 mg/kg of body weight was administered once. For the multidose phase, a daily rhu-pGSN dose of 6, 12, or 24 mg/kg was given on 3 consecutive days. Adverse events (AEs) were generally mild in both treatment groups irrespective of dose. The only serious AE (SAE) in the single-dose phase was a non-drug-related pneumonia in a rhu-pGSN recipient who died after institution of comfort care. One single-dose placebo recipient had a drug-related AE (maculo-papular rash). In the multidose phase, there were 2 SAEs in 1 placebo recipient, including a fatal pulmonary embolism. In the 18 rhu-pGSN recipients in the multidose phase, there were no serious or drug-related AEs, and nausea and increased blood pressure were each reported in 2 patients. The median rhu-pGSN half-life exceeded 17 h with all dosing regimens, and supraphysiologic levels were maintained throughout the 24-h dosing interval in the 2 highest dosing arms. Rhu-pGSN was well tolerated overall in CAP patients admitted to non-ICU beds, justifying a larger proof-of-concept trial in an ICU population admitted with sCAP. (This study has been registered at ClinicalTrials.gov under identifier NCT03466073.).

Recombinant Human Plasma Gelsolin Improves Survival and Attenuates Lung Injury in a Murine Model of Multidrug-Resistant Pseudomonas aeruginosa Pneumonia

Background

Plasma gelsolin (pGSN) is an abundant circulating protein quickly consumed by extensive tissue damage. Marked depletion is associated with later poor outcomes in diverse clinical circumstances. Repletion with recombinant human (rhu)-pGSN in animal models of inflammation lessens mortality and morbidity.

Methods

Neutropenic mice were treated with different meropenem doses ±12 mg of rhu-pGSN commencing 1 day before an intratracheal challenge with multidrug-resistant Pseudomonas aeruginosa. Survival, bacterial counts, and pulmonary pathology were compared between corresponding meropenem groups with and without rhu-pGSN.

Results

Overall survival was 35/64 (55%) and 46/64 (72%) in mice given meropenem without and with rhu-pGSN, respectively (Δ = 17%; 95% CI, 1-34). In control mice receiving meropenem 1250 mg/kg/d where the majority died, the addition of rhu-pGSN increased survival from 5/16 (31%) to 12/16 (75%) (Δ = 44%; 95% CI, 13-75). Survival with minor lung injury was found in 26/64 (41%) mice receiving only meropenem, vs 38/64 (59%) in mice given meropenem plus rhu-pGSN (Δ = 19%; 95% CI, 2-36).

Conclusions

In a series of dose-ranging experiments, both mortality and lung injury were reduced by the addition of rhu-pGSN to meropenem against carbapenem-resistant P. aeruginosa. Rhu-pGSN offers a novel candidate therapy for antibiotic-resistant pneumonia.

Recombinant Human Plasma Gelsolin Stimulates Phagocytosis while Diminishing Excessive Inflammatory Responses in Mice with Pseudomonas aeruginosa Sepsis

Plasma gelsolin (pGSN) is a highly conserved abundant circulating protein, characterized by diverse immunomodulatory activities including macrophage activation and the ability to neutralize pro-inflammatory molecules produced by the host and pathogen. Using a murine model of Gram-negative sepsis initiated by the peritoneal instillation of Pseudomonas aeruginosa Xen 5, we observed a decrease in the tissue uptake of IRDye^®800CW 2-deoxyglucose, an indicator of inflammation, and a decrease in bacterial growth from ascitic fluid in mice treated with intravenous recombinant human plasma gelsolin (pGSN) compared to the control vehicle. Pretreatment of the murine macrophage line RAW264.7 with pGSN, followed by addition of Pseudomonas aeruginosa Xen 5, resulted in a dose-dependent increase in the proportion of macrophages with internalized bacteria. This increased uptake was less pronounced when cells were pretreated with pGSN and then centrifuged to remove unbound pGSN before addition of bacteria to macrophages. These observations suggest that recombinant plasma gelsolin can modulate the inflammatory response while at the same time augmenting host antibacterial activity.

Gelsolin: a new biomarker of disease activity in SLE patients associated with HDL-c

OBJECTIVES

To identify potential biomarkers of disease activity analysing the proteome of high-density lipoprotein (HDL) particles from SLE patients in clinical remission and when they develop a flare compared with a healthy control group.

METHODS

Quantitative proteomic analyses of purified HDL were performed using Tandem Mass Tag isobaric tag-labelling and nanoLC-Orbitrap (nLC-MS/MS) from nine SLE patients in clinical remission when they developed a flare and from nine healthy controls (9-9-9). We verified the identified proteins by Western blot and ELISA in a cohort of 104 SLE women patients, 46 healthy women and 14 SLE patients when a flare developed.

RESULTS

We found 17 proteins with a significant fold-change (>1.1) compared with the control group. In lupus patients experiencing a flare compared with those in remission, we identified four proteins with a significant fold-change (C4, Indian Hedgehog protein, S100A8 and gelsolin). Plasma gelsolin (pGSN) levels were decreased in the 104 SLE patients (176.02(74.9) mcg/l) compared with the control group (217.13(86.7) mcg/l); P=0.005 and when they developed a clinical flare (104.84(41.7) mcg/l); P=0.002). pGSN levels were associated with HDL cholesterol levels (r = 0.316, P<0.001). Antimalarial treated patients showed significant higher levels of pGSN (214.56(88.94) mcg/l regarding 170.35(66.36) mcg/l); P = 0.017.

CONCLUSION

Decreased pGSN are associated with clinical disease activity in SLE patients. Antimalarial treatment and HDL cholesterol are associated with higher levels of pGSN.

Plasma gelsolin levels in patients with psoriatic arthritis: a possible novel marker

BACKGROUND

Psoriatic arthritis (PsA) is an inflammatory disorder affecting the joints of psoriatic patients. Gelsolin regulated the actin assembly and disassembly. Reduction in plasma gelsolin levels was detected in tissue damages, including trauma, sepsis, and chronic inflammatory disorders.

OBJECTIVES

The study aims to investigate the potential role of gelsolin in PsA and to determine the association between gelsolin and the disease activity.

METHODS

Plasma gelsolin levels were measured in 76 PsA patients in comparison with 40 patients having psoriasis only and 40 age- and sex -matched healthy controls.

RESULTS

Plasma gelsolin levels were decreased in PsA patients compared to controls and psoriasis-only patients (p ˂ 0.0001). The optimal cutoff point of gelsolin was 172.5 mg/L. Gelsolin showed 92.1% sensitivity and 95% specificity in detecting PsA. But, it had 92.1% sensitivity and 80% specificity in differentiating between psoriasis and PsA. Plasma gelsolin showed a significant negative correlation with inflammatory markers as C-reactive protein and erythrocyte sedimentation rate (p < 0.0001 and p = 0.039; respectively). A significant negative correlation between plasma gelsolin and PsA activity was detected (p < 0.0001). The PsA activity was defined by the Disease Activity for Psoriatic Arthritis Score and the Composite Psoriatic Disease Activity Index.

CONCLUSIONS

The plasma gelsolin levels were decreased in PsA patients, suggesting that gelsolin may be implicated in the chronic joint inflammation process. Plasma gelsolin seems to be a useful predictive biomarker for diagnosing PsA and monitoring the disease activity.Key Points• This study introduces an unprecedented focus within which the relationship between the levels of plasma gelsolin and PsA is investigated• The study examines the potential role of gelsolin in PsA, and detects the association between gelsolin and the arthritis activity.• There were decreased plasma gelsolin levels in PsA patients. So, gelsolin can constitute a role in the chronic joint inflammation process.• Gelsolin may be a useful biomarker for diagnosing of PsA and monitoring the disease activity.

Dysregulation of the actin scavenging system and inhibition of DNase activity following severe thermal injury

Background

Circulating cell‐free DNA (cfDNA) is not found in healthy subjects, but is readily detected after thermal injury and may contribute to the risk of multiple organ failure. The hypothesis was that a postburn reduction in DNase protein/enzyme activity could contribute to the increase in cfDNA following thermal injury.

Methods

Patients with severe burns covering at least 15 per cent of total body surface area were recruited to a prospective cohort study within 24 h of injury. Blood samples were collected from the day of injury for 12 months.

Results

Analysis of blood samples from 64 patients revealed a significant reduction in DNase activity on days 1–28 after injury, compared with healthy controls. DNase protein levels were not affected, suggesting the presence of an enzyme inhibitor. Further analysis revealed that actin (an inhibitor of DNase) was present in serum samples from patients but not those from controls, and concentrations of the actin scavenging proteins gelsolin and vitamin D‐binding protein were significantly reduced after burn injury. In a pilot study of ten military patients with polytrauma, administration of blood products resulted in an increase in DNase activity and gelsolin levels.

Conclusion

The results of this study suggest a novel biological mechanism for the accumulation of cfDNA following thermal injury by which high levels of actin released by damaged tissue cause a reduction in DNase activity. Restoration of the actin scavenging system could therefore restore DNase activity, and reduce the risk of cfDNA‐induced host tissue damage and thrombosis.

Flightless I exacerbation of inflammatory responses contributes to increased colonic damage in a mouse model of dextran sulphate sodium-induced ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by cytokine driven inflammation that disrupts the mucosa and impedes intestinal structure and functions. Flightless I (Flii) is an immuno-modulatory protein is a member of the gelsolin family of actin-remodelling proteins that regulates cellular and inflammatory processes critical in tissue repair. Here we investigated its involvement in UC and show that Flii is significantly elevated in colonic tissues of patients with inflammatory bowel disease. Using an acute murine model of colitis, we characterised the contribution of Flii to UC using mice with low (Flii+/-), normal (Flii+/+) and high Flii (FliiTg/Tg). High levels of Flii resulted in significantly elevated disease severity index scores, increased rectal bleeding and degree of colon shortening whereas, low Flii expression decreased disease severity, reduced tissue inflammation and improved clinical indicators of UC. Mice with high levels of Flii had significantly increased histological disease severity and elevated mucosal damage with significantly increased inflammatory cell infiltrate and significantly higher levels of TNF-α, IFN-γ, IL-5 and IL-13 pro-inflammatory cytokines. Additionally, Flii overexpression resulted in decreased β-catenin levels, inhibited Wnt/β-catenin signalling and impaired regeneration of colonic crypts. These studies suggest that high levels of Flii, as is observed in patients with UC, may adversely affect mucosal healing via mechanisms involving Th1 and Th2 mediated tissue inflammation and Wnt/β-catenin signalling pathway.

Development of a Novel Diagnostic Biomarker Set for Rheumatoid Arthritis Using a Proteomics Approach

Background

Rheumatoid arthritis (RA) is an autoimmune disease that starts with inflammation of the synovial membrane. Studies have been conducted to develop methods for efficient diagnosis of RA and to identify the mechanisms underlying RA development. Blood samples can be useful for detecting disturbance of homeostasis in patients with RA. Nanoliquid chromatography-tandem mass spectrometry (LC-MS/MS) is an efficient proteomics approach to analyze blood sample and quantify serum proteins.

Methods

Serum samples of 18 healthy controls and 18 patients with RA were analyzed by LC-MS/MS. Selected candidate biomarkers were validated by enzyme-linked immunosorbent assay (ELISA) using sera from 43 healthy controls and 44 patients with RA.

Results

Thirty-eight proteins were significantly differentially expressed by more than 2-fold in healthy controls and patients with RA. Based on a literature survey, we selected six candidate RA biomarkers. ELISA was used to evaluate whether these proteins effectively allow distinguishing patients with RA from healthy controls and monitoring drug efficacy. SAA4, gelsolin, and vitamin D-binding protein were validated as potential biomarkers of RA for screening and drug efficacy monitoring of RA.

Conclusions

We identified a panel of three biomarkers for RA which has potential for application in RA diagnosis and drug efficacy monitoring. Further, our findings will aid in understanding the pathogenesis of RA.

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

Gelsolin, an actin-depolymerizing protein expressed both in extracellular fluids and in the cytoplasm of a majority of human cells, has been recently implicated in a variety of both physiological and pathological processes. Its extracellular isoform, called plasma gelsolin (pGSN), is present in blood, cerebrospinal fluid, milk, urine, and other extracellular fluids. This isoform has been recognized as a potential biomarker of inflammatory-associated medical conditions, allowing for the prediction of illness severity, recovery, efficacy of treatment, and clinical outcome. A compelling number of animal studies also demonstrate a broad spectrum of beneficial effects mediated by gelsolin, suggesting therapeutic utility for extracellular recombinant gelsolin. In the review, we summarize the current data related to the potential of pGSN as an inflammatory predictor and therapeutic target, discuss gelsolin-mediated mechanisms of action, and highlight recent progress in the clinical use of pGSN.

Validation of an automated immune turbidimetric assay for serum gelsolin and its possible clinical utility in sepsis

BACKGROUND

Studies showing the potential predictive value of the actin-binding protein gelsolin, in critically ill patients are scarce. Moreover, even up to now a rapid automated measurement of gelsolin has still remained a challenge. Therefore, we developed and validated an automated serum gelsolin immune turbidimetric assay for possible clinical use.

METHODS

Validation of serum gelsolin assay was performed on a Cobas 8000/c502 analyzer (Roche) according to the second edition of Eurachem guidelines. Furthermore, we also studied the diagnostic value of serum gelsolin in sepsis when investigating sera of septic (n = 25), systemic inflammatory response syndrome (SIRS; n = 8) and control patients (n = 14). We compared our previously published Western blot data with those of the new turbidimetric assay.

RESULTS

The sample volume was 7 μL and the assay time was 10 minutes. The detection limit was 0.72 mg/L, intra- and inter-assay imprecision remained in most cases less than 5% expressed as CV. Recovery was found to be 84.56%-93.52% and linearity study gave an appropriate correlation coefficient by linear regression analysis (r²  = .998). Septic patients exhibited lower (P = .015) first-day serum gelsolin levels than SIRS patients, which confirmed our previous Western blot results. The determined cut-off point for serum gelsolin was 14.05 mg/L (sensitivity: 75%; specificity: 60%) when investigating its diagnostic value in sepsis.

CONCLUSION

Based on the results, our immune turbidimetric measurement offers a rapid and accurate quantitation of gelsolin in human serum samples. Serum gelsolin seems a promising additional diagnostic marker of sepsis which has to be further investigated.

Identification of novel biomarkers for adult-onset-immunodeficiency (AOID) syndrome using serum proteomics

OBJECTIVE

To identify the candidate protein biomarkers of adult-onset-immunodeficiency (AOID) syndrome using serum proteomics.

METHODS

Screening and verification phases were performed in the study. A total of 97 serum samples were classified into three groups: AOID patients with opportunistic infections (active AOID), AOID patients without opportunistic infections (inactive AOID), and healthy control. In the screening phase, pooled sera collected from patients and healthy control in each group were separated by 2D-gel electrophoresis, analyzed for differentially expressed proteins and identified for biomarkers using LC/MS. In the verification phase, the protein candidates were selected for confirmation by western blotting.

RESULTS

The analysis revealed 35 differentially expressed proteins. Three proteins including haptoglobin, gelsolin, and transthyretin, were selected for verification. The results showed that the levels of haptoglobin in both active and inactive AOID groups were significantly higher than that in the control group, while the levels of gelsolin in the active AOID group were significantly lower than that in the inactive AOID group. The level of transthyretin in the active AOID group was also significantly lower than that in the control group.

CONCLUSIONS

The comparison of serum proteins between the three groups revealed three candidates which are related to chronic inflammatory diseases. Haptoglobin and transthyretin biomarkers could be applied in clinical assessment for monitor of disease outcome, including for the study of AOID pathogenesis.

Plasma Gelsolin Induced Glomerular Fibrosis via the TGF-β1/Smads Signal Transduction Pathway in IgA Nephropathy

Glomerular fibrosis has been shown to be closely related to the progression and prognosis of IgA nephropathy (IgAN). However, mechanism underlying IgAN glomerular fibrosis remains unclear. Recently, our study showed that plasma gelsolin (pGSN) was decreased in the serum of an IgAN mouse model and that pGSN deposition was found in the glomeruli. Another cytokine, TGF-β1, which is closely related to glomerular fibrosis, was also found to be highly expressed in the glomeruli. In the present study, we report that pGSN induces glomerular fibrosis through the TGF-β1/Smads signal transduction pathway. This is supported by the following findings: human mesangial cells (HMCs) show remarkable morphological changes and proliferation in response to co-stimulation with pGSN and polymeric IgA1 (pIgA1) from IgAN patients compared to other controls. Moreover, ELISA assays showed that more TGF-β1 secretion was found in HMCs supernatants in the co-stimulation group. Further experiments showed increased TGF-β1, Smad3, p-Smad2/3, Smad4, and collagen 1 and decreased Smad7 expression in the co-stimulation group. Our present study implied that the synergistic effect of pGSN and pIgA induced glomerular fibrosis via the TGF-β1/Smads signal transduction pathway. This might be a potential mechanism for the glomerular fibrosis observed in IgAN patients.

Cytoskeletal Regulation of Inflammation and Its Impact on Skin Blistering Disease Epidermolysis Bullosa Acquisita

Actin remodelling proteins regulate cytoskeletal cell responses and are important in both innate and adaptive immunity. These responses play a major role in providing a fine balance in a cascade of biological events that results in either protective acute inflammation or chronic inflammation that leads to a host of diseases including autoimmune inflammation mediated epidermolysis bullosa acquisita (EBA). This review describes the role of the actin cytoskeleton and in particular the actin remodelling protein called Flightless I (Flii) in regulating cellular inflammatory responses and its subsequent effect on the autoimmune skin blistering disease EBA. It also outlines the potential of an antibody based therapy for decreasing Flii expression in vivo to ameliorate the symptoms associated with EBA.

Fragmented gelsolins are increased in rheumatoid arthritis-associated interstitial lung disease with usual interstitial pneumonia pattern

BACKGROUND

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) occurs in 10%-30% of patients with RA, and interstitial lung disease (ILD) is associated with increased mortality in up to 10% of patients with RA. The pathogenesis of RA-ILD is virtually unknown. The aim of this study is to investigate the proteins related to UIP pattern by comparing to OP pattern in RA-ILD using proteome analysis of bronchoalveolar lavage fluid (BALF).

METHODS

Proteomic differences in BALF were compared between the UIP pattern and OP pattern by examining BALF from 5 patients with the UIP pattern and 7 patients with the OP pattern by two-dimensional gel electrophoresis and mass spectrometry.

RESULTS

In individual comparisons of BALF samples, the levels of the protein gelsolin and Ig kappa chain C region were significantly higher in the UIP pattern than in the OP pattern. In contrast, the levels of α-1 antitrypsin, CRP, haptoglobin β, and surfactant protein A (isoform number 5) were all significantly higher in the OP pattern than in the UIP pattern. Gelsolin was cleaved into two fragments, a C-terminal half and N-terminal half, and the levels of both were significantly higher in the UIP pattern than in the OP pattern.

CONCLUSIONS

Fragmented gelsolins may be associated with the pathogenesis of fibrosis in RA-ILD.

Plasma gelsolin as a biomarker of acute rheumatic carditis

BACKGROUND

Acute rheumatic fever is an autoimmune, inflammatory, and multi-systemic disease secondary to pharyngitis and is caused by group A streptococcus. In developing countries, acute rheumatic fever is the most common cause of acquired heart disease. Gelsolin is a calcium-dependent, multi-functional actin-regulatory protein circulating in the plasma of healthy human beings. The correlation between blood gelsolin levels and inflammatory conditions suggests the potential benefit of gelsolin as a prognostic marker. The aim of the present study was to appraise the association of gelsolin and acute rheumatic carditis in childhood.

MATERIALS AND METHODS

Plasma gelsolin levels were measured and echocardiographic examinations were performed in patients (n=37) with acute rheumatic carditis and compared with those of age- and gender-matched healthy controls (n=24).

RESULTS

The plasma gelsolin levels in children with acute rheumatic carditis were significantly lower compared with controls (197±218 versus 322±255 mg/L, p=0.039). There was a significant correlation among gelsolin levels and the grade of mitral regurgitation (p=0.030), left ventricular end-diastolic diameter (p=0.017), and left ventricular end-systolic diameter (p=0.028) at diagnosis.

CONCLUSIONS

Levels of the gelsolin plasma isoform were decreased in patients with acute rheumatic carditis compared with healthy controls. Gelsolin may be used as a biochemical marker for acute rheumatic carditis.