Fibrinogen, Fibrinogen-like 1 and Fibrinogen-like 2 Proteins, and Their Effects

Fibrinogen/albumin ratio is associated with first-ever cardiovascular events in patients with peritoneal dialysis

OBJECTIVE

The fibrinogen/albumin ratio (FAR) is a novel inflammatory indicator, which has been associated with cardiovascular disease. However, the relationship between FAR and cardiovascular event (CVE) in patients with peritoneal dialysis (PD) remains unclear. This study aims to clarify the relationship between FAR and first-ever CVE in patients with PD.

METHODS

A total of 278 patients were enrolled between January 2012 and June 2021. They were defined as the high FAR group and the low FAR group based on the median FAR value (0.107). The primary outcome was the occurrence of first-ever CVE. Kaplan-Meier's curves and Cox regression analysis were used to analyse the relationship between FAR and first-ever CVE in patients with PD. Forest plots were employed to depict the relationship between FAR and first-ever CVE in each subgroup.

RESULTS

The average follow-up period was 40.26 ± 28.27 months. A total of 101 (36.3%) patients developed first-ever CVE. Kaplan-Meier's analysis showed that there was a higher risk of first-ever CVE (p = .002) in the high FAR group. Multivariate Cox regression analysis showed that FAR ≥ 0.107 and age were independently associated with the risk of first-ever CVE in patients with PD. Receiver operating characteristic (ROC) analysis showed that FAR had a greater predicting value on the first-ever CVE.

CONCLUSIONS

High levels of FAR are independently associated with an increased risk of first-ever CVE in patients with PD.

Fibrinogen and colorectal cancer: A study of the Chinese population

Fibrinogen has been associated with a variety of malignancies, including colorectal cancer (CRC). However, there is no study on the relationship between fibrinogen and CRC specifically in the Chinese population. The objective of this study was to analyze the relationship between fibrinogen and CRC in the Chinese population. This study included consecutive inpatients undergoing colonoscopies (April 2015‒June 2022). A total of 3,595 individuals, comprising 468 CRCs and 3,127 controls, were included. Logistic regression models and restricted cubic spline analysis were employed to assess the association between fibrinogen and CRC. When fibrinogen levels were divided into quartiles, the ORs for CRC in Q2, Q3, and Q4 compared to Q1 were 2.72 (95% CI: 1.57-4.74), 4.84 (95% CI: 2.84-8.25), and 9.55 (95% CI: 5.55-16.43), respectively. Restricted cubic spline analysis identified a non-linear association between fibrinogen levels and CRC risk with a threshold of 3.794 (95% CI: 3.747-3.841) g/L. Below this threshold, the CRC risk significantly increased (OR 5.944, 95% CI 4.084-8.65, P < 0.001). These findings may offer new insights for the diagnosis and management of CRC.

Role of fibrinogen-like 2 (FGL2) proteins in implantation: Potential implications and mechanism

Fibrinogen-like (Fgl2) protein belongs to fibrinogen super family, which catalyzes the conversion of prothrombin to thrombin and is involved in the coagulation process. There are two different forms of functional Fgl2 protein: membrane associated Fgl2 (mFgl2) and soluble Fgl2 (sFgl2). mFgl2, as a type II transmembrane protein with property with prothrombinase activity from its N-terminal fragment, was extensively secreted or expressed by inflammatory macrophages, dendritic cells (DCs), Th1 cells and endothelial cells. While sFgl2 was mainly produced by regulatory T cells (Tregs) and then secreted into the vasculature, which contributes to autoimmune disease by regulating maturation of (DCs), polarization of macrophage, inhibiting T cell proliferation and differentiation and inducing apoptosis of B cells. In particular, emerging evidence has shown that Fgl2 is implicated in female reproductive system that contributes to embryo development, ovarian granulosa cells differentiation and implantation failure. This article summarizes the role and potential mechanisms of Fgl2 in reproduction and identifies research gaps along with the future directions.

Serum Soluble Fibrinogen-Like Protein 2 Estimates Increased T-Helper 2 Cytokine, Elevated Disease Severity, and Unfavorable Outcomes in Allergic Rhinitis Patients

OBJECTIVE

Soluble fibrinogen-like protein 2 (sFGL2) may be involved in the pathology and progression of allergic rhinitis (AR) through regulating T-helper (Th)2 cell response. This study aimed to explore the ability of sFGL2 to estimate outcomes in AR patients.

METHODS

sFGL2 was detected in the serum sample of 119 AR patients at baseline and 20 healthy controls (HCs) after enrollment by enzyme-linked immunosorbent assay. In AR patients, disease severity was assessed at baseline as well as 4 weeks (W4) and 8 weeks (W8) after enrollment by the total nasal symptom score (TNSS).

RESULTS

sFGL2 was higher in AR patients than HCs [median (interquartile range): 100.0 (70.0-154.0) vs 47.0 (31.5-78.5) ng/mL] (P < .001). In AR patients, sFGL2 was positively correlated with TNSS score (P = .002), itching score (P = .037), sneezing score (P = .012), and interleukin (IL)-4 (P = .006) at baseline. TNSS score declined from baseline to W8 in AR patients (P < .001). To further explore the association between sFGL2 levels and treatment outcomes, we compared the sFGL2 levels between patients with TNSS scores at W4 or W8 >4 and those with TNSS scores at W4 or W8 ≤4. It was found that sFGL2 was only increased in AR patients with a TNSS score at W4 >4 versus those with a TNSS score at W4 ≤4 (P = .012).

CONCLUSION

Serum sFGL2 is increased in AR patients, and its high level estimates an increased Th2 cytokine and disease severity as well as poor outcomes.

The Promising Role of Selenium and Yeast in the Fight Against Protein Amyloidosis

In recent years, increasing attention has been paid to research on diseases related to the deposition of misfolded proteins (amyloids) in various organs. Moreover, modern scientists emphasise the importance of selenium as a bioelement necessary for the proper functioning of living organisms. The inorganic form of selenium-sodium selenite (redox-active)-can prevent the formation of an insoluble polymer in proteins. It is very important to undertake tasks aimed at understanding the mechanisms of action of this element in inhibiting the formation of various types of amyloid. Furthermore, yeast cells play an important role in this matter as a eukaryotic model organism, which is intensively used in molecular research on protein amyloidosis. Due to the lack of appropriate treatment in the general population, the problem of amyloidosis remains unsolved. This extracellular accumulation of amyloid is one of the main factors responsible for the occurrence of Alzheimer's disease. The review presented here contains scientific information discussing a brief description of the possibility of amyloid formation in cells and the use of selenium as a factor preventing the formation of these protein aggregates. Recent studies have shown that the yeast model can be successfully used as a eukaryotic organism in biotechnological research aimed at understanding the essence of the entire amyloidosis process. Understanding the mechanisms that regulate the reaction of yeast to selenium and the phenomenon of amyloidosis is important in the aetiology and pathogenesis of various disease states. Therefore, it is imperative to conduct further research and analysis aimed at explaining and confirming the role of selenium in the processes of protein misfolding disorders. The rest of the article discusses the characteristics of food protein amyloidosis and their use in the food industry. During such tests, their toxicity is checked because not all food proteins can produce amyloid that is toxic to cells. It should also be noted that a moderate diet is beneficial for the corresponding disease relief caused by amyloidosis.

Fibrinogen: A new player and target on the formation of pre-metastatic niche in tumor metastasis

Tumor metastasis involves a series of complex and coordinated processes, which is the main cause of patient death and still a significant challenge in cancer treatment. Pre-metastatic niches (PMN), a specialized microenvironment that develops in distant organs prior to the arrival of metastatic cancer cells, plays a crucial role in driving tumor metastasis. The development of PMN depends on a complex series of cellular and molecular components including tumor-derived factors, bone marrow-derived cells, resident immune cells, and extracellular matrix. Fibrinogen, a key factor in the typical blood clotting process, is related to tumor metastasis and prognosis, according to a growing body of evidence in recent years. Fibrinogen has emerged as an important factor in mediating the formation of tumor microenvironment. Nevertheless, a clear and detailed mechanism by which fibrinogen promotes tumor metastasis remains unknown. In this review, we first explore the roles of fibrinogen in the development of PMN from four perspectives: immunosuppression, inflammation, angiogenesis, and extracellular matrix remodeling. We highlight the significance of fibrinogen in shaping PMN and discuss its potential therapeutic values, opening new avenues for targeting fibrinogen to prevent or treat metastasis.

Body mass index and fat influences the role of Bifidobacterium genus in lupus patients concerning fibrinogen levels

Introduction

Metabolic disorders and autoimmune diseases elicit distinct yet interconnected manifestations of inflammation, which may be boosted by an excess of body adiposity. The purpose of this investigation was to analyze anthropometric, biochemical, and inflammatory/coagulation variables concerning patients diagnosed with systemic lupus erythematosus (SLE) exploiting low-grade metabolic inflammation (MI), as reference.

Methods

A population stratification by body mass index (BMI), allowed to assess the impact of adiposity on the putative role of gut microbiota composition on coagulation markers. A total of 127 participants with MI and SLE were categorized into two main groups based on their BMI, following WHO criteria: a low BMI group (<30 kg/m2) and a high BMI group (≥30 kg/m2). Each group included recorded data on demographics, comorbidities, and key clinical markers. Anthropometric and body composition variables, clinical features, and inflammatory/coagulation markers were measured while fecal 16S rRNA sequencing was examined at the genus Bifidobacterium. Regression models were fitted to evaluate the relationship between gut microbiota, inflammatory/coagulation markers, and body weight in these types of diseases.

Results

The study revealed worse clinical outcomes in anthropometric, body composition, and clinical markers in low-grade MI conditions as compared to SLE. However, inflammatory and coagulation markers such as C-reactive protein (CRP) and fibrinogen were significantly more elevated in patients with SLE, which was exacerbated by high BMI/ body fat as compared to the other screened groups. An interaction analysis revealed that fibrinogen levels showed different trends when Bifidobacterium was increased depending on BMI/adiposity, which evidenced an effect modification by this microorganism in patients with SLE.

Discussion

These findings underline that gut microbiota composition, particularly the presence of Bifidobacterium, may play a crucial role in modulating inflammation and coagulation processes in patients with SLE and high fat. These insights highlight the potential of targeting gut microbiota as a therapeutic strategy to mitigate inflammation and improve clinical outcomes in SLE patients.

Clonorchis sinensis infection contributes to hepatocellular carcinoma progression via enhancing angiogenesis

BACKGROUND

Clonorchis sinensis (C. sinensis) infection plays an important role in the progression of hepatocarcinogenesis. However, its specific role in HCC progression remains unclear. This study aimed to investigate whether C. sinensis contributes to angiogenesis in HCC.

METHODS

A comprehensive clinical analysis was conducted on 947 HCC patients, divided into two groups: C. sinensis (-) HCC and C. sinensis (+) HCC. Kaplan-Meier survival curves and log-rank tests were utilized to assess survival outcomes. Microvessel density (MVD) was evaluated through CD34 immunohistochemistry on hepatectomy specimens. A chemistry analyzer and blood analyzer were employed to measure the concentration of circulating angiogenesis-related biomarkers. Quantitative reverse transcription-PCR (qRT-PCR) was used to analyze the expression of angiogenesis-related genes (CD34, Ang1, Ang2, VEGF, PDGF) in HCC tissues.

RESULTS

C. sinensis infection was associated with poorer outcomes in HCC patients, with significantly shorter overall survival (OS) (p = 0.014) and recurrence-free survival (RFS) (p<0.001). Notably, C. sinensis infection led to an upregulation of MVD in HCC tissues (p = 0.041). C. sinensis (+) HCC patients exhibited significantly higher levels of circulating angiogenesis-related biomarkers, including MONO (p = 0.004), EOSO (p < 0.001), C3 (p = 0.001), FIB (p = 0.010), PLT (p = 0.003), LDH (p = 0.004), GLDH (p = 0.003), compared to C. sinensis (-) HCC patients. Moreover, qRT-PCR analysis revealed that most angiogenesis-related genes were overexpressed in patients with C. sinensis infection.

CONCLUSION

C. sinensis infection is closely associated with inflammatory responses and may promote metabolic reprogramming in HCC, thereby enhancing its malignant characteristics.

Exploring the effects of 4-chloro-o-phenylenediamine on human fibrinogen: A comprehensive investigation via biochemical, biophysical and computational approaches

Fibrinogen (Fg), an essential plasma glycoprotein involved in the coagulation cascade, undergoes structural alterations upon exposure to various chemicals, impacting its functionality and contributing to pathological conditions. This research article explored the effects of 4-Chloro-o-phenylenediamine (4-Cl-o-PD), a common hair dye component (IUPAC = 1-Chloro-3,4-diaminobenzene), on human fibrinogen through comprehensive computational, biophysical, and biochemical approaches. The formation of a stable ligand-protein complex is confirmed through molecular docking and molecular dynamics simulations, revealing possible interaction having a favorable -4.8 kcal/mol binding energy. Biophysical results, including UV-vis and fluorescence spectroscopies, corroborated with the computational findings, whereas Fourier transform infrared spectroscopy (FT-IR) and circular dichroism spectroscopy (CD) provide insights into the alterations of secondary structures upon interaction with 4-Cl-o-PD. Anilinonaphthalene-sulfonic acid (ANS) fluorescence showed a partially unfolded protein, with enhanced α to β-sheet transition as evidenced by thioflavin T (ThT) spectroscopy and microscopy. Moreover, biochemical assays confirmed the formation of carbonyl compounds that may be responsible for the oxidation of methionine residues in fibrinogen. Electrophoresis and electron microscopy confirmed the formation of aggregates. Our findings elucidate the interaction pattern of 4-Cl-o-PD with Fg, leading to structural perturbation, which may have potential implications for fibrinogen misfolding or its aggregation. Protein aggregation or its misfolded products affect peripheral tissues and the central nervous system. Many chronic progressive diseases, like type II diabetes mellitus, Alzheimer's disease, Parkison's disease, and Creutzfeldt-Jakob disease are associated with intrinsically aberrant disordered proteins. Understanding these interactions may offer new perspectives on the safety and biocompatibility of dye compounds, which may contribute to developing improved strategies for acquired amyloidogenesis.

Comparison of Metabolic Syndrome, Autoimmune and Viral Distinctive Inflammatory Related Conditions as Affected by Body Mass Index

Background: Metabolic inflammation (MI), long COVID (LC) and systemic lupus erythematosus (SLE) share some metabolic common manifestations and inflammatory pathophysiological similarities. Health-related quality of life (HRQoL) and metabolic age are indicators of health status. The "METAINFLAMMATION-CM Y2020/BIO-6600" project, a prospective controlled study, aimed to identify differential diagnostic tools and clinical features among three inflammatory conditions by comparing obesity status (low BMI vs. high BMI). Methods: A total of 272 adults of both Caucasian and Hispanic descent, diagnosed with MI, LC or SLE, and a range of BMI, were recruited. Clinical and phenotypic traits were measured to analyze body composition, metabolic and inflammatory markers, HRQoL data, metabolic age and lifestyle habits using a 3 × 2 (disease × BMI) factorial design. Results: Some inflammatory related variables, such as fibrinogen, RDW (red cell blood distribution width), ESR (erythrocyte sedimentation rate) and NLR (neutrophil/lymphocyte ratio), showed effect modifications depending on the BMI and disease type. In relation to HRQoL, the Physical Component Summary (PCS12) showed no relevant changes, while the Mental Component Summary (MCS12) showed a significant effect modification according to the disease type and BMI (p < 0.05). Furthermore, a significant interaction was identified between the disease type and BMI in relation to metabolic age (p = 0.02). Conclusions: Assessing the impact of BMI on these three inflammatory diseases may help to prevent clinical complications and to design personalized treatments, especially for patients with SLE, who have a worse prognosis with an increased BMI compared to the other two inflammatory diseases.

Proteomic analysis and experimental validation reveal the blood-brain barrier protective of Huanshaodan in the treatment of SAMP8 mouse model of Alzheimer's disease

BACKGROUND

Huanshaodan (HSD) is a Chinese Herbal Compound which has a definite clinical effect on Alzheimer's disease (AD), however, the underlying mechanism remains unclear. The aim of this study is to preliminarily reveal the mechanism of HSD in the treatment of AD model of SAMP8 mice.

METHODS

Chemical composition of HSD and its drug-containing serum were identified by Q-Orbitrap high resolution liquid mass spectrometry. Six-month-old SAMP8 mice were treated with HSD and Donepezil hydrochloride by gavage for 2 months, and Wogonin for 28 days. Behavioral test was performed to test the learning and memory ability of mice. Immunofluorescence (IF) or Western-blot methods were used to detect the levels of pSer404-tau and β-amyloid (Aβ) in the brain of mice. Hematoxylin-eosin (H&E) staining and Transmission electron microscopy (TEM) assay was applied to observe the pathological changes of neurons. Proteomic technology was carried out to analyze and identify the protein network of HSD interventions in AD. Then the pathological process of the revealed AD-related differential proteins was investigated by IF, Q-PCR, Western-blot, Fluorescence in situ hybridization (FISH) and 16S rRNA sequencing methods.

RESULTS

The results showed that HSD and Wogonin, one of the components in its drug-containing serum, can effectively improve the cognitive impairments of SAMP8 mice, protect hippocampal neurons and synapses, and reduce the expression of pSer404-tau and Aβ. HSD and Wogonin reduced the levels of fibrinogen β chain (FGB) and γ chain (FGG), the potential therapeutic targets revealed by proteomics analysis, reduced the colocalization of FGB and FGG with Aβ, ionized calcium binding adaptor molecule 1 (Iba-1), glial fibrillary acidic protein (GFAP), increased level of and myelin basic protein (MBP). Meanwhile, HSD and Wogonin increased ZO-1 and Occludin levels, improved brain microvascular injury, and reduced levels of bacteria/bacterial DNA and lipopolysaccharide (LPS) in the brain of mice. In addition, 16S rRNA sequencing indicated that HSD regulated the structure of intestinal microbiota of mice.

CONCLUSION

The effects of HSD on AD may be achieved by inhibiting the levels of fibrinogen and the interactions on glia cells in the brain, and by modulating the structure of intestinal microbiota and improving the blood-brain barrier function.

Molecular Responses of Anti-VEGF Therapy in Neovascular Age-Related Macular Degeneration: Integrative Insights From Multi-Omics and Clinical Imaging

Purpose

The purpose of this study was to investigate the molecular mechanisms underlying anti-vascular endothelial growth factor (anti-VEGF) efficacy and response variability in neovascular age-related macular degeneration (nAMD) using longitudinal proteomic and metabolomic analysis alongside three-dimensional lesion measurements.

Methods

In this prospective study, 54 treatment-naive patients with nAMD underwent "3+ pro re nata" (3+PRN) anti-VEGF regimens followed for at least 12 weeks. Aqueous humors were collected pre- and post-treatment for proteomic and metabolomic analysis. Three-dimensional optical coherence tomography (OCT) and OCT angiography assessed different types of nAMD lesion volumes and areas.

Results

There were 1350 proteins and 1268 metabolites that were identified in aqueous humors, with 301 proteins and 353 metabolites significantly altered during anti-VEGF treatment, enriched in pathways of angiogenesis, energy metabolism, signal transduction, and neurofunctional regulation. Sixty-seven changes of (Δ) molecules significantly correlated with at least one type of ΔnAMD lesion. Notably, proteins FGA, TALDO1, and ASPH significantly decreased during treatment, with their reductions correlating with greater lesion regression in at least two lesion types. Conversely, despite that YIPF3 also showed significant downregulation, its decrease was associated with poorer regression in total nAMD lesion and subretinal hyper-reflective material.

Conclusions

This study identifies FGA, TALDO1, and ASPH as potential key molecules in the efficacy of anti-VEGF therapy, whereas YIPF3 may be a key factor in poor response. The integration of longitudinal three-dimensional lesion analysis with multi-omics provides valuable insights into the mechanisms and response variability of anti-VEGF treatment in nAMD.

Potential clinical value of fibrinogen-like protein 1 as a serum biomarker for the identification of diabetic cardiomyopathy

Diabetic individuals with diabetic cardiomyopathy (DbCM) present with abnormal myocardial structure and function. DbCM cannot be accurately diagnosed due to the lack of suitable diagnostic biomarkers. In this study, 171 eligible participants were divided into a healthy control (HC), type 2 diabetes mellitus (T2DM) patients without DbCM (T2DM), or DbCM group. Serum fibrinogen-like protein 1 (FGL-1) and other biochemical parameters were determined for all participants. Serum FGL-1 levels were significantly higher in patients with DbCM compared with those in the T2DM group and HCs. Serum FGL-1 levels were negatively correlated with left ventricular fractional shortening and left ventricular ejection fraction (LVEF) and positively correlated with left ventricular mass index in patients with DbCM after adjusting for age, sex and body mass index. Interaction of serum FGL-1 and triglyceride levels on LVEF was noted in patients with DbCM. A composite marker including serum FGL-1 and triglycerides could differentiate patients with DbCM from those with T2DM and HCs with an area under the curve of 0.773 and 0.789, respectively. Composite marker levels were negatively correlated with N-terminal B-type natriuretic peptide levels in patients with DbCM. Circulating FGL-1 may therefore be a valuable index reflecting cardiac functions in DbCM and to diagnose DbCM.

Identification of urine biomarkers of endometriosis-Protein mass spectrometry

INTRODUCTION

Endometriosis is a chronic inflammatory disease that leads to a series of pathological reactions. The basis is a changed proinflammatory activated immune system, which results in more pronounced oxidative stress, disturbed function of proteolysis and cell apoptosis. These processes are crucial in the development of the disease because their dysfunctional activities cause the progression of the disease. It is believed that the proteins excreted in the urine interact with each other and promote pathological processes in endometriosis.

METHODS

We analyzed the urine proteome of patients and aimed to detect a potential protein biomarker for endometriosis in the urine proteome. We collected urine samples from 16 patients with endometriosis and 16 patients in the control group with functional ovarian cysts. The diagnosis for all patients was confirmed through pathohistological analysis. After the preanalytical preparation of the urine, chromatography and mass spectrometry (LC-MS/MS) used the technology of urine proteome analysis.

RESULTS

The main finding was a significantly different concentration of 14 proteins in the urine samples. We recorded a considerably higher concentration of proteins that have a significant role in activating the immune system (SELL), iron metabolism (HAMP) and cell apoptosis (CHGA) in endometriosis compared to controls. Proteins having an antioxidant function (SOD1) and a role in proteolysis of the extracellular matrix (MMP-9) were significantly reduced in endometriosis compared to controls.

CONCLUSION

Consistent with the known pathogenesis of endometriosis, the study results complement the pathological responses that occur with disease progression.

Vitamin D3 improved hypoxia-induced lung injury by inhibiting the complement and coagulation cascade and autophagy pathway

BACKGROUND

Pulmonary metabolic dysfunction can cause lung tissue injury. There is still no ideal drug to protect against hypoxia-induced lung injury, therefore, the development of new drugs to prevent and treat hypoxia-induced lung injury is urgently needed. We aimed to explore the ameliorative effects and molecular mechanisms of vitamin D3 (VD3) on hypoxia-induced lung tissue injury.

METHODS

Sprague-Dawley (SD) rats were randomly divided into three groups: normoxia, hypoxia, and hypoxia + VD3. The rat model of hypoxia was established by placing the rats in a hypobaric chamber. The degree of lung injury was determined using hematoxylin and eosin (H&E) staining, lung water content, and lung permeability index. Transcriptome data were subjected to differential gene expression and pathway analyses. In vitro, type II alveolar epithelial cells were co-cultured with hepatocytes and then exposed to hypoxic conditions for 24 h. For VD3 treatment, the cells were treated with low and high concentrations of VD3.

RESULTS

Transcriptome and KEGG analyses revealed that VD3 affects the complement and coagulation cascade pathways in hypoxia-induced rats, and the genes enriched in this pathway were Fgb/Fga/LOC100910418. Hypoxia can cause increases in lung edema, inflammation, and lung permeability disruption, which are attenuated by VD3 treatment. VD3 weakened the complement and coagulation cascade in the lung and liver of hypoxia-induced rats, characterized by lower expression of fibrinogen alpha chain (Fga), fibrinogen beta chain (Fgb), protease-activated receptor 1 (PAR1), protease-activated receptor 3 (PAR3), protease-activated receptor 4 (PAR4), complement (C) 3, C3a, and C5. In addition, VD3 improved hypoxic-induced type II alveolar epithelial cell damage and inflammation by inhibiting the complement and coagulation cascades. Furthermore, VD3 inhibited hypoxia-induced autophagy in vivo and in vitro, which was abolished by the mitophagy inducer, carbonyl cyanide-m-chlorophenylhydrazone (CCCP).

CONCLUSION

VD3 alleviated hypoxia-induced pulmonary edema by inhibiting the complement and coagulation cascades and autophagy pathways.

A Bioartificial Pancreas with "Immune Stealth" and Continuous Oxygen Supply for Islet Transplantation

Transplantation of microencapsulated islet cells remains a promising strategy for the normalization of glucose metabolism control in type 1 diabetes mellitus. However, vigorous host immunologic rejection, fibrotic overgrowth around the microcapsules, and poor oxygen supply often lead to graft failure. Herein, a bioartificial pancreas is constructed, which incorporates the "stealth effect" based on polyethylene glycol copolymers and the high oxygen-carrying performance of fluorinated nanoparticles. Polycationic poly(l-lysine)-grafted-poly(ethylene glycol) is successfully coated on the surface of alginate microcapsules through electrostatic interaction, which can not only resist fibrinogen adhesion and avoid excessive fibrosis around the microcapsules but also isolate the host immune system from attacking, achieving a "stealth effect" of microencapsulated islet cells. Furthermore, the coloading of fluoride-based O2 nanocarriers gives them enhanced oxygen-carrying and continuous oxygen supply capabilities, thereby effectively prolonging the survival of islet cells. The intracapsular islet cells still display similar cell viability and almost normal insulin secretion function even in long-term culture under hypoxic conditions. Collectively, here a new approach is opened for microencapsulated islets to efficiently evade host immune attack and improve oxygen supply and a promising strategy is provided for islet transplantation in type 1 diabetes mellitus.

Pathogenic Role of Fibrinogen in the Neuropathology of Multiple Sclerosis: A Tale of Sorrows and Fears

Multiple sclerosis (MS) is an autoimmune demyelinating neurodegenerative disease of the central nervous system (CNS) due to injury of the myelin sheath by immune cells. The clotting factor fibrinogen is involved in the pathogenesis of MS by triggering microglia and the progress of neuroinflammation. Fibrinogen level is correlated with MS severity; consequently, inhibition of the fibrinogen cascade may reduce MS neuropathology. Thus, this review aimed to clarify the potential role of fibrinogen in the pathogenesis of MS and how targeting of fibrinogen affects MS neuropathology. Accumulation of fibrinogen in the CNS may occur independently or due to disruption of blood-brain barrier (BBB) integrity in MS. Fibrinogen acts as transduction and increases microglia activation which induces the progression of inflammation, oxidative stress, and neuronal injury. Besides, brain fibrinogen impairs the remyelination process by inhibiting the differentiation of oligodendrocyte precursor cells. These findings proposed that fibrinogen is associated with MS neuropathology through interruption of BBB integrity, induction of neuroinflammation, and demyelination with inhibition of the remyelination process by suppressing oligodendrocytes. Therefore, targeting of fibrinogen and/or CD11b/CD18 receptors by metformin and statins might decrease MS neuropathology. In conclusion, inhibiting the expression of CD11b/CD18 receptors by metformin and statins may decrease the pro-inflammatory effect of fibrinogen on microglia which is involved in the progression of MS.

Fibrinogen-like protein 2 in inflammatory diseases: A future therapeutic target

Fibrinogen-like protein 2 (FGL2), a member of the fibrinogen family, exists as a membrane-bound protein with immune-associated coagulation activity and a soluble form possessing immunosuppressive functions. The immunomodulatory role of FGL2 is evident in fibrin deposition-associated inflammatory diseases and cancer, suggesting that FGL2 expression could be exploited as a disease biomarker and a therapeutic target. Recently, in vitro studies and knockout and transgenic animal FGL2 models have been used by us and others to reveal the involvement of FGL2 in the pathogenesis of various inflammatory diseases. This review summarizes our current knowledge of the immunomodulatory role of FGL2 in inflammatory diseases and examines the role of FGL2 as a potential therapeutic target.