The role of thrombomodulin lectin-like domain in inflammation

Group XIV C-type lectins: emerging targets in tumor angiogenesis

C-type lectins, distinguished by a C-type lectin binding domain (CTLD), are an evolutionarily conserved superfamily of glycoproteins that are implicated in a broad range of physiologic processes. The group XIV subfamily of CTLDs are comprised of CD93, CD248/endosialin, CLEC14a, and thrombomodulin/CD141, and have important roles in creating and maintaining blood vessels, organizing extracellular matrix, and balancing pro- and anti-coagulative processes. As such, dysregulation in the expression and downstream signaling pathways of these proteins often lead to clinically relevant pathology. Recently, group XIV CTLDs have been shown to play significant roles in cancer progression, namely tumor angiogenesis and metastatic dissemination. Interest in therapeutically targeting tumor vasculature is increasing and the search for novel angiogenic targets is ongoing. Group XIV CTLDs have emerged as key moderators of tumor angiogenesis and metastasis, thus offering substantial therapeutic promise for the clinic. Herein, we review our current knowledge of group XIV CTLDs, discuss each's role in malignancy and associated potential therapeutic avenues, briefly discuss group XIV CTLDs in the context of two other relevant lectin families, and offer future direction in further elucidating mechanisms by which these proteins function and facilitate tumor growth.

Clinical implications of septic cardiomyopathy: A narrative review

Sepsis is caused by the body's dysregulated response to infection, which can lead to multiorgan injury and death. Patients with sepsis may develop acute cardiac dysfunction, termed septic cardiomyopathy, which is a global but reversible dysfunction of both sides of the heart. This narrative review discusses the mechanistic changes in the heart during septic cardiomyopathy, its diagnosis, existing treatment options regarding severity and course, and emerging treatment approaches. Although no standardized definition for septic cardiomyopathy exists, it is described as a reversible myocardial dysfunction that typically resolves within 7 to 10 days. Septic cardiomyopathy is often diagnosed based on electrocardiography, cardiac magnetic resonance imaging, biomarkers, and direct invasive and noninvasive measures of cardiac output. Presently, the treatment of septic cardiomyopathy is similar to that of sepsis, primarily focusing on acute interventions. Treatments for cardiomyopathy often include angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and diuretics. However, because of profound hypotension in sepsis, many cardiomyopathy treatments are contraindicated in patients with septic cardiomyopathy. Substantial efforts have been made to study the pathophysiological mechanisms and diagnostic options; however, the lack of a uniform definition for septic cardiomyopathy is challenging for physicians when considering treatments. Another challenge for physicians is that the treatment for septic cardiomyopathy has only focused on acute intervention, whereas the treatment for other cardiomyopathies has been provided on a long-term basis. A better understanding of the underlying mechanisms of septic cardiomyopathy may contribute to the development of a unified definition of the condition and novel treatment options.

THE NEUROENDOTHELIAL AXIS IN TRAUMATIC BRAIN INJURY: MECHANISMS OF MULTIORGAN DYSFUNCTION, NOVEL THERAPIES, AND FUTURE DIRECTIONS

ABSTRACT

Severe traumatic brain injury (TBI) often initiates a systemic inflammatory response syndrome, which can potentially culminate into multiorgan dysfunction. A central player in this cascade is endotheliopathy, caused by perturbations in homeostatic mechanisms governed by endothelial cells due to injury-induced coagulopathy, heightened sympathoadrenal response, complement activation, and proinflammatory cytokine release. Unique to TBI is the potential disruption of the blood-brain barrier, which may expose neuronal antigens to the peripheral immune system and permit neuroinflammatory mediators to enter systemic circulation, propagating endotheliopathy systemically. This review aims to provide comprehensive insights into the "neuroendothelial axis" underlying endothelial dysfunction after TBI, identify potential diagnostic and prognostic biomarkers, and explore therapeutic strategies targeting these interactions, with the ultimate goal of improving patient outcomes after severe TBI.

Novel nucleotide variations in the thrombomodulin (THBD) gene involved in coagulation pathways can increase the risk of recurrent pregnancy loss (RPL)

Recurrent pregnancy loss (RPL) is a common but complex complication in fertility conditions, affecting about 15-20% of couples. Although several causes have been proposed for RPL, it occurs in about 35-60% of cases without a known explanation. A strong assumption is that genetic factors play a role in the etiology and pathophysiology of PRL. Therefore, several genes are proposed as candidates in the pathogenesis of RPL. The current study aimed to investigate the effects of nucleotide changes in the THBD (thrombomodulin) gene as an RPL-related candidate gene. This gene encodes a cell receptor for thrombin and is involved in reproductive loss in RPL cases. Its involvement in the natural anticoagulant system has been extensively studied. By genetic screening of the entire coding and noncoding regions of the THBD gene, we found twenty-seven heterozygous and homozygous nucleotide changes. Ten of them led to amino acid substitutions, seven variants were identified in the promoter region, and eight of them occurred in 3'UTR. Potentially, the pathogenicity effects of these variations on THBD protein were evaluated by several prediction tools. The numerous genomic variations prompted noticeable modifications of the protein's structural and functional properties. Furthermore, in-silico scores were consistent with deleterious effects for these mutations. The results of this study provide genetic information that will be useful in the future for clinicians, scientists, and students to understand the unknown causes of RPL better. It may also pave the way for developing diagnostic/prognostic approaches to help treat PRL patients.

A Review of Proposed Mechanisms in Rheumatoid Arthritis and Therapeutic Strategies for the Disease

Rheumatoid arthritis (RA) is characterized by synovial edema, inflammation, bone and cartilage loss, and joint degradation. Patients experience swelling, stiffness, pain, limited joint movement, and decreased mobility as the condition worsens. RA treatment regimens often come with various side effects, including an increased risk of developing cancer and organ failure, potentially leading to mortality. However, researchers have proposed mechanistic hypotheses to explain the underlying causes of synovitis and joint damage in RA patients. This review article focuses on the role of synoviocytes and synoviocytes resembling fibroblasts in the RA synovium. Additionally, it explores the involvement of epigenetic regulatory systems, such as microRNA pathways, silent information regulator 1 (SIRT1), Peroxisome proliferatoractivated receptor-gamma coactivator (PGC1-α), and protein phosphatase 1A (PPM1A)/high mobility group box 1 (HMGB1) regulators. These mechanisms are believed to modulate the function of receptors, cytokines, and growth factors associated with RA. The review article includes data from preclinical and clinical trials that provide insights into potential treatment options for RA.

Post-Translational Oxidative Modifications of Hemostasis Proteins: Structure, Function, and Regulation

Reactive oxygen species (ROS) are constantly generated in a living organism. An imbalance between the amount of generated reactive species in the body and their destruction leads to the development of oxidative stress. Proteins are extremely vulnerable targets for ROS molecules, which can cause oxidative modifications of amino acid residues, thus altering structure and function of intra- and extracellular proteins. The current review considers the effect of oxidation on the structural rearrangements and functional activity of hemostasis proteins: coagulation system proteins such as fibrinogen, prothrombin/thrombin, factor VII/VIIa; anticoagulant proteins - thrombomodulin and protein C; proteins of the fibrinolytic system such as plasminogen, tissue plasminogen activator and plasminogen activator inhibitor-1. Structure and function of the proteins, oxidative modifications, and their detrimental consequences resulting from the induced oxidation or oxidative stress in vivo are described. Possible effects of oxidative modifications of proteins in vitro and in vivo leading to disruption of the coagulation and fibrinolysis processes are summarized and systematized, and the possibility of a compensatory mechanism in maintaining hemostasis under oxidative stress is analyzed.

HMGB1: a double-edged sword and therapeutic target in the female reproductive system

HMGB1 that belongs to the High Mobility Group-box superfamily, is a nonhistone chromatin associated transcription factor. It is present in the nucleus of eukaryotes and can be actively secreted or passively released by kinds of cells. HMGB1 is important for maintaining DNA structure by binding to DNA and histones, protecting it from damage. It also regulates the interaction between histones and DNA, affecting chromatin packaging, and can influence gene expression by promoting nucleosome sliding. And as a DAMP, HMGB1 binding to RAGE and TLRs activates NF-κB, which triggers the expression of downstream genes like IL-18, IL-1β, and TNF-α. HMGB1 is known to be involved in numerous physiological and pathological processes. Recent studies have demonstrated the significance of HMGB1 as DAMPs in the female reproductive system. These findings have shed light on the potential role of HMGB1 in the pathogenesis of diseases in female reproductive system and the possibilities of HMGB1-targeted therapies for treating them. Such therapies can help reduce inflammation and metabolic dysfunction and alleviate the symptoms of reproductive system diseases. Overall, the identification of HMGB1 as a key player in disease of the female reproductive system represents a significant breakthrough in our understanding of these conditions and presents exciting opportunities for the development of novel therapies.

Magnitude and kinetics of the human immune cell response associated with severe dengue progression by single-cell proteomics

Approximately 5 million dengue virus-infected patients progress to a potentially life-threatening severe dengue (SD) infection annually. To identify the immune features and temporal dynamics underlying SD progression, we performed deep immune profiling by mass cytometry of PBMCs collected longitudinally from SD progressors (SDp) and uncomplicated dengue (D) patients. While D is characterized by early activation of innate immune responses, in SDp there is rapid expansion and activation of IgG-secreting plasma cells and memory and regulatory T cells. Concurrently, SDp, particularly children, demonstrate increased proinflammatory NK cells, inadequate expansion of CD16⁺ monocytes, and high expression of the FcγR CD64 on myeloid cells, yet a signature of diminished antigen presentation. Syndrome-specific determinants include suppressed dendritic cell abundance in shock/hemorrhage versus enriched plasma cell expansion in organ impairment. This study reveals uncoordinated immune responses in SDp and provides insights into SD pathogenesis in humans with potential implications for prediction and treatment.

How to manage coagulopathies in critically ill patients

Coagulopathy is a severe and frequent complication in critically ill patients, for which the pathogenesis and presentation may be variable depending on the underlying disease. Based on the dominant clinical phenotype, the current review differentiates between hemorrhagic coagulopathies, characterized by a hypocoagulable and hyperfibrinolysis state, and thrombotic coagulopathies with a systemic prothrombotic and antifibrinolytic phenotype. We discuss the differences in pathogenesis and treatment of the common coagulopathies.

A missense mutation in lectin domain of thrombomodulin causing functional deficiency

Thrombomodulin (TM) functions in coagulation, fibrinolysis and inflammation by its cofactor activity for protein C, thrombin-activatable fibrinolysis inhibitor (TAFI) activation and high mobility group box 1 (HMGB1) degradation induced by thrombin. It has been widely reported that mutations in TM are related to thromboembolic diseases but hardly in lectin domain. Here we report our findings about the functional deficiencies in TM caused by substitution of aspartate with tyrosine at residue 126. Three patients suffering from recurrent thromboembolic diseases were identified with this mutation and their plasma soluble TM levels were decreased. Transfected cells expressing wild-type TM or the variant and corresponding proteins were used to examine TM functions in vitro. The cofactor activity of the mutant for protein C, TAFI activation was reduced to approximately 50% and 60% respectively. Loss in anti-inflammation due to weakened HMGB1 degradation was also observed. And the study with thrombosis models of mice suggested the decreased inhibition of thrombus development of the mutant. Together the results showed deleterious changes on TM function caused by this mutation, which may explain the thrombophilia tendency of the patients. This work provided supportive evidence that mutation in lectin domain of TM might be related to thrombotic diseases and may help us better understand the physiological roles of TM.

Multimodal measurement of glycocalyx degradation during coronary artery bypass grafting

Background

Glycocalyx shedding and subsequent endothelial dysfunction occur in many conditions, such as in sepsis, in critical illness, and during major surgery such as in coronary artery bypass grafting (CABG) where it has been shown to associate with organ dysfunction. Hitherto, there is no consensus about the golden standard in measuring glycocalyx properties in humans. The objective of this study was to compare different indices of glycocalyx shedding and dysfunction. To this end, we studied patients undergoing elective CABG surgery, which is a known cause of glycocalyx shedding.

Materials and methods

Sublingual glycocalyx thickness was measured in 23 patients by: 1) determining the perfused boundary region (PBR)-an inverse measure of glycocalyx thickness-by means of sidestream dark field imaging technique. This is stated double, 2) measuring plasma levels of the glycocalyx shedding products syndecan-1, hyaluronan, and heparan sulfate and 3) measuring plasma markers of impaired glycocalyx function and endothelial activation (Ang-2, Tie-2, E-selectin, and thrombomodulin). Measurements were performed directly after induction, directly after onset of cardiopulmonary bypass (CPB), and directly after cessation of CPB. We assessed changes over time as well as correlations between the various markers.

Results

The PBR increased from 1.81 ± 0.21 μm after induction of anesthesia to 2.27 ± 0.25 μm (p < 0.0001) directly after CPB was initiated and did not change further during CPB. A similar pattern was seen for syndecan-1, hyaluronan, heparan sulfate, Ang-2, Tie-2, and thrombomodulin. E-selectin levels also increased between induction and the start of CPB and increased further during CPB. The PBR correlated moderately with heparan sulfate, E-selectin, and thrombomodulin and weakly with Syndecan-1, hyaluronan, and Tie-2. Shedding markers syndecan-1 and hyaluronan correlated with all functional markers. Shedding marker heparan sulfate only correlated with Tie-2, thrombomodulin, and E-selectin. Thrombomodulin correlated with all shedding markers.

Conclusion

Our results show that glycocalyx thinning, illustrated by increased sublingual PBR and increased levels of shedding markers, is paralleled with impaired glycocalyx function and increased endothelial activation in CABG surgery with CPB. As correlations between different markers were limited, no single marker could be identified to represent the glycocalyx in its full complexity.

Visualization of Domain- and Concentration-Dependent Impact of Thrombomodulin on Differential Regulation of Coagulation and Fibrinolysis

BACKGROUND

 Thrombomodulin (TM) functions as a dual modulator-anticoagulant and antifibrinolytic potential-by the thrombin-dependent activation of protein C and thrombin-activatable fibrinolysis inhibitor (TAFI). Activated TAFI cleaves the C-terminal lysine of partially degraded fibrin and inhibits both plasminogen binding and its activation on the fibrin surface. We have reported previously that activated platelets initiate fibrin network formation and trigger fibrinolysis after the accumulation of tissue-type plasminogen activator and plasminogen.

OBJECTIVE

 To analyze the effects of domain-deletion variants of TM on coagulation and fibrinolysis at different concentrations.

METHODS

 Domain-deletion variants of TM, such as D123 (all extracellular regions), E3456 (minimum domains for thrombin-dependent activation of protein C and TAFI), and E456 (minimum domains for that of protein C but not TAFI), were used at 0.25 to 125 nM for turbidimetric assay to determine the clotting time and clot lysis time and to visualize fibrin network formation and lysis in platelet-containing plasma.

RESULTS AND CONCLUSIONS

 A low concentration of either D123 or E3456, but not of E456, prolonged clot lysis time, and delayed the accumulation of fluorescence-labeled plasminogen at the activated platelets/dense fibrin area due to effective TAFI activation. Conversely, only the highest concentrations of all three TM variants delayed the clotting time, though fibrin network formation in the vicinity of activated platelets was almost intact. TAFI activation might be affected by attenuation in thrombin activity after the clot formation phase. These findings suggest that the spatiotemporal balance between the anticoagulant and antifibrinolytic potential of TM is controlled in domain- and concentration-dependent manners.

Upregulated miR-18a-5p in Colony Forming Unit-Hill’s in Subclinical Cardiovascular Disease and Metformin Therapy; MERIT Study

Colony forming unit-Hill’s (CFU-Hill’s) colonies are hematopoietic-derived cells that participate in neovasculogenesis and serve as a biomarker for vascular health. In animals, overexpression of miR-18a-5p was shown to be pro-atherogenic. We had shown that well-controlled type 1 diabetes mellitus (T1DM) is characterized by an inflammatory state, endothelial dysfunction, and reduced number of CFU-Hill’s, a model of subclinical cardiovascular disease (CVD). MERIT study explored the role of miR-18a-5p expression in CFU-Hill’s colonies in T1DM, and the cardioprotective effect of metformin in subclinical CVD. In T1DM, miR-18a-5p was significantly upregulated whereas metformin reduced it to HC levels. MiR-18a-5p was inversely correlated with CFU-Hill’s colonies, CD34+, CD34+CD133+ cells, and positively with IL-10, C-reactive protein, vascular endothelial growth factor-D (VEGF-D), and thrombomodulin. The receiver operating characteristic curve demonstrated, miR-18a-5p as a biomarker of T1DM, and upregulated miR-18a-5p defining subclinical CVD at HbA1c of 44.5 mmol/mol (pre-diabetes). Ingenuity pathway analysis documented miR-18a-5p inhibiting mRNA expression of insulin-like growth factor-1, estrogen receptor-1, hypoxia-inducible factor-1α cellular communication network factor-2, and protein inhibitor of activated STAT 3, whilst metformin upregulated these mRNAs via transforming growth factor beta-1 and VEGF. We confirmed the pro-atherogenic effect of miR-18a-5p in subclinical CVD and identified several target genes for future CVD therapies.

MiR-550a-3p restores damaged vascular smooth muscle cells by inhibiting thrombomodulin in an <em>in vitro</em> atherosclerosis model

Thrombomodulin (TM) is involved in the pathological process of atherosclerosis; however, the underlying mechanism remains unclear. Oxidised low-density lipoprotein (Ox-LDL; 100 μg/mL) was used to induce human vascular smooth muscle cells (HVSMCs) into a stable atherosclerotic cell model. The expression levels of miR-550a-3p and TM were detected by real-time reverse transcription-polymerase chain reaction. Cell proliferation was estimated using CCK8 and EDU assays. Wound scratch and transwell assays were used to measure the ability of cells to invade and migrate. Propidium iodide fluorescence-activated cell sorting was used to detect apoptosis and cell cycle changes. A dual-luciferase reporter assay was performed to determine the binding of miR-550a-3p to TM. Our results suggested the successful development of a cellular atherosclerosis model. Our data revealed that TM overexpression significantly promoted the proliferation, invasion, migration, and apoptosis of HVSMCs as well as cell cycle changes. Upregulation of miR-550a-3p inhibited the growth and metastasis of HVSMCs. Furthermore, miR-550a-3p was confirmed to be a direct target of TM. Restoration of miR-550a-3p expression rescued the effects of TM overexpression. Thus, miR-550a-3p might play a role in atherosclerosis and, for the first time, normalised the function of injured vascular endothelial cells by simultaneous transfection of TM and miR-550a-3p. These results suggest that the miR-550a-3p/TM axis is a potential therapeutic target for atherosclerosis.

Thrombomodulin and von willebrand factor as markers of endothelial dysfunction in patients with chronic kidney disease

The aim of research was to study the levels of thrombomodulin (TM) and von Willebrand factor (VWF) in the serum and urine of patients with chronic kidney disease (CKD)as diagnostic markers of endothelial dysfunction. The study involved 140 patients with CKD. The clinical diagnosis was determined based on standard methods of patients examination according to the kidney diseases classification and protocols of CKD patients management. The concentrations of TM and VWF in serum and urine were quantified by ELISA. A generalized endothelial dysfunction in the vessels of the whole body, including the kidneys and high concentration of TM and FVF in the serum and urine of patients with a diabetic nephropathy have been found. The concentration of TM and VWF in the serum of patients with a chronic glomerulonephritis was at the same level as in the serum of healthy individuals, while those in urine significantly exceeded the control values, indicating endothelial damage in the glomeruli of the kidneys due to exposure to pro-inflammatory cytokines. In our opinion, the studied markers will contribute to the timely diagnosis of endothelial dysfunction in patients with CKD and to the development of criteria for prescribing antiplatelet agents in glomerular kidney disease.

Biomarker Changes in Response to a 12-Week Supplementation of an Oral Nutritional Supplement Enriched with Protein, Vitamin D and HMB in Malnourished Community Dwelling Older Adults with Sarcopenia

Malnutrition and sarcopenia commonly overlap and contribute to adverse health outcomes. Previously, chronic supplementation with two oral nutritional supplements (ONS), control (C_ONS) and experimental ONS enriched with protein, vitamin D and β-hydroxy β-methylbutyrate (HMB) (E_ONS), improved muscle strength and quality in malnourished sarcopenic older adults, with E_ONS demonstrating early strength benefits at 12 weeks. To understand the underlying biological mechanisms contributing to the observed early strength benefits of E_ONS, we examined serum biomarker changes in response to 12-week supplementation. Serum samples (E_ONS (n = 90) and C_ONS (n = 103)) collected at baseline and 12 weeks were analyzed. Biomarkers (n = 243) were measured using multiplexed immunoassay, commercial immunoassays and ELISAs. Sixty markers were excluded with levels below assay detection limits. Sixteen biomarkers significantly changed in response to both interventions including nutritional and metabolic markers. Thirteen biomarkers significantly changed in response to E_ONS but not C_ONS. Increases in immunoglobulins, myoglobin, total protein, vitamin E and magnesium were observed with E_ONS. Inflammation-related ferritin and osteopontin decreased, while soluble receptors for cytokines increased, suggesting decreased inflammation. Sex hormone-binding globulin associated with sarcopenia also decreased with E_ONS. Biomarkers reflective of multiple biological systems were impacted by nutritional intervention in sarcopenic older adults. Incremental biomarker changes were observed in response to E_ONS containing HMB that possibly link to improvements in skeletal muscle health.

Absence of the lectin-like domain of thrombomodulin reduces HSV-1 lethality of mice with increased microglia responses

Background

Herpes simplex virus 1 (HSV-1) can induce fatal encephalitis. Cellular factors regulate the host immunity to affect the severity of HSV-1 encephalitis. Recent reports focus on the significance of thrombomodulin (TM), especially the domain 1, lectin-like domain (TM-LeD), which modulates the immune responses to bacterial infections and toxins and various diseases in murine models. Few studies have investigated the importance of TM-LeD in viral infections, which are also regulated by the host immunity.

Methods

In vivo studies comparing wild-type and TM-LeD knockout mice were performed to determine the role of TM-LeD on HSV-1 lethality. In vitro studies using brain microglia cultured from mice or a human microglia cell line to investigate whether and how TM-LeD affects microglia to reduce HSV-1 replication in brain neurons cultured from mice or in a human neuronal cell line.

Results

Absence of TM-LeD decreased the mortality, tissue viral loads, and brain neuron apoptosis of HSV-1-infected mice with increases in the number, proliferation, and phagocytic activity of brain microglia. Moreover, TM-LeD deficiency enhanced the phagocytic activity of brain microglia cultured from mice or of a human microglia cell line. Co-culture of mouse primary brain microglia and neurons or human microglia and neuronal cell lines revealed that TM-LeD deficiency augmented the capacity of microglia to reduce HSV-1 replication in neurons.

Conclusions

Overall, TM-LeD suppresses microglia responses to enhance HSV-1 infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02426-w.

Recombinant thrombomodulin domain 1 rescues pathological angiogenesis by inhibition of HIF-1α-VEGF pathway

Pathological angiogenesis (PA) contributes to various ocular diseases, including age-related macular degeneration, diabetic retinopathy, and retinopathy of prematurity, which are major causes of blindness over the world. Current treatments focus on anti-vascular endothelial growth factor (VEGF) therapy, but persistent avascular retina, recurrent intravitreal neovascularization, and general adverse effects are reported. We have previously found that recombinant thrombomodulin domain 1 (rTMD1) can suppress vascular inflammation. However, the function of rTMD1 in VEGF-induced PA remains unknown. In this study, we found that rTMD1 inhibited VEGF-induced angiogenesis in vitro. In an oxygen induced retinopathy (OIR) animal model, rTMD1 treatment significantly decreased retinal neovascularization but spared normal physiological vessel growth. Furthermore, loss of TMD1 significantly promoted PA in OIR. Meanwhile, hypoxia-inducible factor-1α, the transcription factor that upregulates VEGF, was suppressed after rTMD1 treatment. The levels of interleukin-6, and intercellular adhesion molecule-1 were also significantly suppressed. In conclusion, our results indicate that rTMD1 not only has dual effects to suppress PA and inflammation in OIR, but also can be a potential HIF-1α inhibitor for clinical use. These data bring forth the possibility of rTMD1 as a novel therapeutic agent for PA.

Elevated circulating thrombomodulin levels in systemic lupus erythematosus: a systematic review and meta-analysis

OBJECTIVES

Thrombomodulin (TM) is closely related to the pathogenesis of autoimmune diseases, including systemic lupus erythematosus (SLE). However, current evidence on circulating TM levels in SLE patients is contradictory. We conducted this meta-analysis to more accurately assess circulating TM levels in patients with SLE and lupus nephritis (LN) and to analyze related influencing factors.

METHODS

Systematic search of relevant documents was conducted in PubMed, Embase, and The Cochrane Library databases (up to 28 February 2021). Studies on the comparison of circulating TM between SLE patients and controls were screened and evaluated for inclusion. Random-effects model analysis was applied to calculate the combined standardized mean difference (SMD) with a 95% confidence interval (CI). Heterogeneity was estimated by Q statistics and I2.

RESULTS

A total of 353 articles were identified, 14 provided adequate information for this study finally. The results illustrated that SLE patients had higher TM levels than healthy controls (SMD =0.38, 95% CI: 0.02 to 0.74, p=0.04). Circulating TM levels were increased in patients with active SLE compared to inactive SLE patients (SMD=1.12, 95% CI: 0.03 to 2.20, p=0.04). In addition, circulating TM levels of SLE patients with LN were higher than those without LN (SMD=4.55, 95% CI: 1.97 to 7.12, p=0.001).

CONCLUSIONS

The circulating TM levels in SLE patients are enhanced. In addition, circulating TM levels may be practical in reflecting the disease activity and nephritis involvement of SLE patients.

TCF21+ mesenchymal cells contribute to testis somatic cell development, homeostasis, and regeneration in mice

Testicular development and function rely on interactions between somatic cells and the germline, but similar to other organs, regenerative capacity declines in aging and disease. Whether the adult testis maintains a reserve progenitor population remains uncertain. Here, we characterize a recently identified mouse testis interstitial population expressing the transcription factor Tcf21. We found that TCF21lin cells are bipotential somatic progenitors present in fetal testis and ovary, maintain adult testis homeostasis during aging, and act as potential reserve somatic progenitors following injury. In vitro, TCF21lin cells are multipotent mesenchymal progenitors which form multiple somatic lineages including Leydig and myoid cells. Additionally, TCF21+ cells resemble resident fibroblast populations reported in other organs having roles in tissue homeostasis, fibrosis, and regeneration. Our findings reveal that the testis, like other organs, maintains multipotent mesenchymal progenitors that can be potentially leveraged in development of future therapies for hypoandrogenism and/or infertility.

Stable expression of the human thrombomodulin transgene in pig endothelial cells is associated with a reduction in the inflammatory response

BACKGROUND

Xenotransplantation is associated with an inflammatory response. The proinflammatory cytokine, TNF-α, downregulates the expression of thrombomodulin (TBM), and induces coagulation dysfunction. Although human (h) TBM-transgenic pigs (p) have been developed to reduce coagulation dysfunction, the effect of TNF-α on the expression of hTBM and its functional activity has not been fully investigated. The aims of this study were to investigate (i) whether the expression of hTBM on pig (p) cells is down-regulated during TNF-α stimulation, and (ii) whether cells from hTBM pigs regulate the inflammatory response.

METHODS

TNF-α-producing T, B, and natural killer cells in blood from baboons with pig heart or kidney xenografts were investigated by flow cytometry. TNF-α staining in the grafts was detected by immunohistochemistry. Aortic endothelial cells (AECs) from GTKO/CD46 and GTKO/CD46/hTBM pigs were stimulated by hTNF-α, and the expression of the inflammatory/coagulation regulatory protein, TBM, was investigated.

RESULTS

After pig organ xenotransplantation, there was a trend to increases in TNF-α-producing T and natural killer cells in the blood of baboons. In vitro observations demonstrated that after hTNF-α stimulation, there was a significant reduction in the expression of endogenous pTBM on pAECs, and a significant increase in the expression of inflammatory molecules. Blocking of NF-κB signaling significantly up-regulated pTBM expression, and suppressed the inflammatory response induced by hTNF-α in pAECs. Whereas the expression of pTBM mRNA was significantly reduced by hTNF-α stimulation, hTBM expression on the GTKO/CD46/hTBM pAECs was not affected. Furthermore, after hTNF-α stimulation, there was significant suppression of expression of inflammatory molecules on GTKO/CD46/hTBM pAECs compared to GTKO/CD46 pAECs.

CONCLUSIONS

The stable expression of hTBM in pig cells may locally regulate the inflammatory response. This will help suppress the inflammatory response and prevent coagulation dysregulation after xenotransplantation.

Recombinant Thrombomodulin Attenuates Preeclamptic Symptoms by Inhibiting High-Mobility Group Box 1 in Mice

Preeclampsia (PE) is a common gestational complication that involves systemic endothelial dysfunction and inflammatory responses primarily due to placental damage. Recombinant thrombomodulin (rTM), a novel anticoagulant clinically used for disseminated intravascular coagulation, is reported to have a unique anti-inflammatory endothelial repair function by inhibiting proinflammatory mediator high-mobility group box 1 (HMGB1). Despite the severe patient outcomes, there are currently no effective therapeutic options to treat PE. Here, we verified the efficacy of rTM as a novel therapeutic agent for PE using a murine model and human trophoblast cells. We revealed the therapeutic potential of rTM in an angiotensin II(Ang II)-induced PE mouse model. Injection of rTM significantly attenuated clinical features of PE, such as hypertension, proteinuria, fetal growth restriction, and impaired placental vasculature. Elevation of maternal soluble fms-like tyrosine kinase-1 (sFlt-1), a well-accepted causal factor of PE that induces systemic endothelial dysfunction, was suppressed in response to rTM treatment. Supporting these findings, our in vitro experiments revealed that rTM reduces Ang II-triggered overproduction of sFlt-1 in human trophoblast cells. Moreover, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), well-known key inflammatory mediators in PE pathogenesis, were diminished by rTM. SiRNA knockdown experiments further determined that these processes were directly mediated by HMGB1. Our studies demonstrate that rTM exerts its clinical effect as HMBG1 inhibitor and ameliorates placental dysfunction, which is central to PE pathogenesis. Our findings suggest that rTM could be a promising therapeutic that significantly improve the outcomes of PE patients.

The Lectin-Like Domain of Thrombomodulin Inhibits β1 Integrin-Dependent Binding of Human Breast Cancer-Derived Cell Lines to Fibronectin

Thrombomodulin is a molecule with anti-coagulant and anti-inflammatory properties. Recently, thrombomodulin was reported to be able to bind extracellular matrix proteins, such as fibronectin and collagen; however, whether thrombomodulin regulates the binding of human breast cancer-derived cell lines to the extracellular matrix remains unknown. To investigate this, we created an extracellular domain of thrombomodulin, TMD123-Fc, or domain deletion TM-Fc proteins (TM domain 12-Fc, TM domain 23-Fc) and examined their bindings to fibronectin in vitro by ELISA. The lectin-like domain of thrombomodulin was found to be essential for the binding of the extracellular domain of thrombomodulin to fibronectin. Using a V-well cell adhesion assay or flow cytometry analysis with fluorescent beads, we found that both TMD123-Fc and TMD12-Fc inhibited the binding between β1 integrin of human breast cancer-derived cell lines and fibronectin. Furthermore, TMD123-Fc and TMD12-Fc inhibited the binding of activated integrins to fibronectin under shear stress in the presence of Ca²⁺ and Mg²⁺ but not under strong integrin-activation conditions in the presence of Mg²⁺ without Ca²⁺. This suggests that thrombomodulin Fc fusion protein administered exogenously at a relatively early stage of inflammation may be applied to the development of new therapies that inhibit the binding of β1 integrin of breast cancer cell lines to fibronectin.

The lectin-like domain of thrombomodulin is a drug candidate for both prophylaxis and treatment of liver ischemia and reperfusion injury in mice

Ischemia and reperfusion injury (IRI) can occur in any tissue or organ. With respect to liver transplantation, the liver grafts from donors by definition experience transient ischemia and subsequent blood reflow. IRI is a problem not only in organ transplantation but also in cases of thrombosis or circulatory disorders such as mesenteric ischemia, myocardial, or cerebral infarction. We have reported that recombinant human soluble thrombomodulin (rTM), which is currently used in Japan to treat disseminated intravascular coagulation (DIC), has a protective effect and suppresses liver IRI in mice. However, rTM may not be fully safe to use in humans because of its inherent anticoagulant activity. In the present study, we used a mouse liver IRI model to explore the possibility that the isolated lectin-like domain of rTM (rTMD1), which has no anticoagulant activity, could be effective as a therapeutic modality for IRI. Our results indicated that rTMD1 could suppress ischemia and reperfusion-induced liver damage in a dose-dependent manner without concern of associated hemorrhage. Surprisingly, rTMD1 suppressed the liver damage even after IR insult had occurred. Taken together, we conclude that rTMD1 may be a candidate drug for prevention of and therapy for human liver IRI without the possible risk of hemorrhage.

Recombinant thrombomodulin lectin-like domain attenuates porphyromonas gingivalis lipopolysaccharide-induced osteoclastogenesis and periodontal bone resorption

BACKGROUND

Evidence demonstrates that the thrombomodulin (TM) lectin domain (TMD1) exerts anti-inflammatory functions. Lipopolysaccharides derived from Porphyromonas gingivalis (Pg-LPS) are considered a major pathogenic factor for chronic periodontitis, promoting inflammation, osteoclastogenesis and alveolar bone resorption. Herein, we aimed to evaluate the potential therapeutic effect of recombinant TMD1 (rTMD1) in suppression of Pg-LPS-induced osteoclastogenesis and periodontal bone loss.

METHODS

In vitro, the effects of Pg-LPS, tumor necrosis factor (TNF)-α and rTMD1 on osteoclast differentiation were investigated using receptor activator of nuclear factor-κB ligand (RANKL)-stimulated RAW 264.7 macrophages. In vivo, the effects of rTMD1 treatment were evaluated in a model of experimental periodontitis induced by direct injection of Pg-LPS into the vestibular gingiva.

RESULTS

Administration of Pg-LPS to RANKL-stimulated RAW 264.7 macrophages resulted in upregulation of CD86 and osteoclast marker (eg, Dc-stamp and Trap) gene expression and increase of pro-inflammatory cytokine production (e.g., TNF-α) during osteoclast differentiation, and rTMD1 can attenuate these effects. Also, rTMD1 inhibited Pg-LPS-enhanced in vitro bone resorption in a dose-dependent manner. Moreover, TNF-α promoted phosphorylation of p38 and ERK during osteoclast differentiation, and the signal activation can be inhibited by rTMD1. Finally, treatment with rTMD1 hindered Pg-LPS-induced alveolar bone loss in experimental periodontitis in mice.

CONCLUSION

Our study demonstrated that rTMD1 attenuates Pg-LPS-enhanced M1 macrophage polarization, osteoclastogenesis and periodontal bone resorption and thus holds therapeutic promise for periodontitis.

Thrombomodulin as a Physiological Modulator of Intravascular Injury

Thrombomodulin (TM), which is predominantly expressed on the endothelium, plays an important role in maintaining vascular homeostasis by regulating the coagulation system. Intravascular injury and inflammation are complicated physiological processes that are induced by injured endothelium-mediated pro-coagulant signaling, necrotic endothelial- and blood cell-derived damage-associated molecular patterns (DAMPs), and DAMP-mediated inflammation. During the hypercoagulable state after endothelial injury, TM is released into the intravascular space by proteolytic cleavage of the endothelium component. Recombinant TM (rTM) is clinically applied to patients with disseminated intravascular coagulation, resulting in protection from tissue injury. Recent studies have revealed that rTM functions as an inflammatory regulator beyond hemostasis through various molecular mechanisms. More specifically, rTM neutralizes DAMPs, including histones and high mobility group box 1 (HMGB1), suppresses excessive activation of the complement system, physiologically protects the endothelium, and influences both innate and acquired immunity. Neutrophil extracellular traps (NETs) promote immunothrombosis by orchestrating platelets to enclose infectious invaders as part of the innate immune system, but excessive immunothrombosis can cause intravascular injury. However, rTM can directly and indirectly regulate NET formation. Furthermore, rTM interacts with mediators of acquired immunity to resolve vascular inflammation. So far, rTM has shown good efficacy in suppressing inflammation in various experimental models, including thrombotic microangiopathy, sterile inflammatory disorders, autoimmune diseases, and sepsis. Thus, rTM has the potential to become a novel tool to regulate intravascular injury via pleiotropic effects.

Targeting NLRP3 inflammasome as a promising approach for treatment of diabetic nephropathy: Preclinical evidences with therapeutic approaches

Diabetes mellitus is an increasingly prevalent disease around the globe. The epidemic of diabetes mellitus and its complications pretenses the foremost health threat globally. Diabetic nephropathy is the notable complication in diabetes, leading to end-stage renal disease (ESRD) and premature death. Abundant experimental evidence indicates that oxidative stress and inflammation are the important mediators in diabetic kidney diseases and interlinked with various signal transduction molecular mechanisms. Inflammasomes are the critical components of innate immunity and are recognized as a critical mediator of inflammation and autoimmune disorders. NOD-like receptor protein 3 (NLRP3) inflammasome is the well-characterized protein and it exhibits the sterile inflammation through the regulation of pro-inflammatory cytokines interleukin (IL)-1β and IL-18 production in tissues. In recent years, the role of NLRP3 inflammasome in the pathophysiology of diabetic kidney diseases in both clinical and experimental studies has generated great interest. In the current review, we focused on and discussed the role of NLRP3 inflammasome in diabetic nephropathy. A literature review was performed using online databases namely, PubMed, Scopus, Google Scholar and Web of science to explore the possible pharmacological interventions that blunt the NLRP3 inflammasome-caspase-1-IL-1β/IL-18 axis and shown to have a beneficial effect in diabetic kidney diseases. This review describes the inhibition of NLRP3 inflammasome activation as a promising therapeutic target for drug discovery in future.

Therapeutic Potential of Thrombomodulin in Renal Fibrosis of Nephrotoxic Serum Nephritis in Wistar-Kyoto Rats

BACKGROUND

Recombinant human soluble thrombomodulin (rhTM) was approved in 2008 and has been used for treatment of disseminated intravascular coagulation in Japan. The antifibrotic effects of rhTM in acute exacerbation of idiopathic pulmonary fibrosis are well established, but the therapeutic potential of rhTM in renal fibrosis remains poorly understood.

METHODS

Nephrotoxic serum nephritis (NTS-N) was induced in 22 female Wistar-Kyoto (WKY) rats on day 0. Rats were administered either rhTM or vehicle intraperitoneally, every day from day 4 to day 55. Rats were sacrificed on day 56 when renal fibrosis was established and renal morphological investigations were performed. In vitro, rat renal fibroblasts (NRK-49F) were pretreated with rhTM or saline, and expression levels of profibrogenic gene induced by thrombin were analyzed by real-time reverse transcription polymerase chain reaction.

RESULTS

Compared to WKY-GN-vehicle rats, the body weights of WKY-GN-rhTM rats were significantly greater on day 55. By day 56, rhTM had significantly reduced serum creatinine levels in NTS-N. On the other hand, urinary protein excretion was comparable between the two treatment groups throughout the study. The percentage of Masson trichrome-positive areas in WKY-GN-rhTM rats was significantly lower compared to that in WKY-GN-vehicle rats. Glomerular fibrin deposition was significantly reduced in WKY-GN-rhTM rats. In addition, rhTM significantly reduced the renal cortical mRNA expression levels of TNF-α, Toll-like receptor 4, MYD88, TGF-β, αSMA, collagen I, collagen III, fibronectin, and protease-activated receptor 1 (PAR1), a thrombin receptor. In vitro, thrombin stimulation of NRK-49F cells significantly enhanced the mRNA expression levels of αSMA and PAR1, and these upregulations were significantly reduced by pretreatment with rhTM.

CONCLUSIONS

Administration of rhTM after establishment of crescentic glomerulonephritis (GN) attenuated the subsequent development of renal fibrosis in NTS-N, possibly in part by inhibiting thrombin-mediated fibrogenesis. Our results suggest that rhTM may offer a therapeutic option for limiting the progression of chronic kidney disease in crescentic GN.

The efficacy of recombinant human soluble thrombomodulin (rhsTM) treatment for acute exacerbation of idiopathic pulmonary fibrosis: a systematic review and meta-analysis

Background

Acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) is devastating with no established treatment. This phenomenon involves disordered coagulation and excessive inflammatory reactions. As recombinant human soluble thrombomodulin (rhsTM) possesses anti-coagulative and anti-inflammatory properties, the medicine is expected to improve the prognosis of the disease. The aim of this study was to summarize current evidence regarding benefits and harms of rhsTM treatment for AE of IPF.

Method

Patients with AE of IPF were eligible for the review and all of the other types of interstitial pneumonias were excluded. The effect of rhsTM treatment on the outcomes such as all-cause mortality was estimated in comparison to conventional therapy. Primary studies of any design aside from a case report were reviewed. Electronic databases such as Medline and EMBASE were searched from 2002 through August 14, 2019. Two reviewers independently selected eligible reports and extracted relevant data. A risk of bias of individual studies was assessed similarly. Meta-analysis was conducted for univariate results if at least three studies were available for the same outcome.

Result

Out of a total of 390 records identified, eight studies were first deemed eligible and four of them were finally focused for the review. Only one study was a prospective trial and a historical control was employed in all studies. An overall risk of bias was rated as serious in three out of four studies. A total of 169 subjects were included. Two out of three studies that reported 3-month all-cause mortality by univariate analysis demonstrated beneficial effects of rhsTM treatment and a pooled analysis demonstrated that rhsTM treatment improved 3-month all-cause mortality with a risk ratio of 0.50 (95% confidence interval (CI): 0.35–0.72). All two studies reporting multivariate results demonstrated that rhsTM treatment improved 3-month all-cause mortality with odds ratios of 0.21 (95% CI: 0.05–0.91) and 0.25 (95% CI: 0.09–0.68), respectively. There were no serious adverse events.

Conclusion

The rhsTM treatment was demonstrated to improve 3-month all-cause mortality of AE of IPF with no serious adverse events. However, these findings should be interpreted with caution due to a small number of studies and serious risk of bias.

The Role of HMGB1, a Nuclear Damage-Associated Molecular Pattern Molecule, in the Pathogenesis of Lung Diseases

Significance: High-mobility group protein box 1 (HMGB1), a ubiquitous nuclear protein, regulates chromatin structure and modulates the expression of many genes involved in the pathogenesis of lung cancer and many other lung diseases, including those that regulate cell cycle control, cell death, and DNA replication and repair. Extracellular HMGB1, whether passively released or actively secreted, is a danger signal that elicits proinflammatory responses, impairs macrophage phagocytosis and efferocytosis, and alters vascular remodeling. This can result in excessive pulmonary inflammation and compromised host defense against lung infections, causing a deleterious feedback cycle. Recent Advances: HMGB1 has been identified as a biomarker and mediator of the pathogenesis of numerous lung disorders. In addition, post-translational modifications of HMGB1, including acetylation, phosphorylation, and oxidation, have been postulated to affect its localization and physiological and pathophysiological effects, such as the initiation and progression of lung diseases. Critical Issues: The molecular mechanisms underlying how HMGB1 drives the pathogenesis of different lung diseases and novel therapeutic approaches targeting HMGB1 remain to be elucidated. Future Directions: Additional research is needed to identify the roles and functions of modified HMGB1 produced by different post-translational modifications and their significance in the pathogenesis of lung diseases. Such studies will provide information for novel approaches targeting HMGB1 as a treatment for lung diseases.

Myeloid and Plasmacytoid Dendritic Cells and Cancer - New Insights

Dendritic cells (DCs) use effective mechanisms to combat antigens and to bring about adaptive immune responses through their ability to stimulate näive T cells. At present, four major cell types are categorised as DCs: Classical or conventional (cDCs), Plasmacytoid (pDCs), Langerhans cells (LCs), and monocyte-derived DCs (Mo-DCs). It was suggested that pDCs, CD1c+ DCs and CD141+ DCs in humans are equivalent to mouse pDCs, CD11b+ DCs and CD8α+ DCs, respectively. Human CD141+ DCs compared to mouse CD8α+ DCs have remarkable functional and transcriptomic similarities. Characteristic markers, transcription factors, toll-like receptors, T helpers (Th) polarisation, cytokines, etc. of DCs are discussed in this review. Major histocompatibility complex (MHC) I and II antigen presentation, cross-presentation and Th polarisation are defined, and the dual role of DCs in the tumour is discussed. Human DCs are the main immune cells that orchestrate the immune response in the tumour microenvironment.

Recombinant Thrombomodulin on Neutrophil Extracellular Traps in Murine Intestinal Ischemia–Reperfusion

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

In multiple-organ dysfunction, an injury affecting one organ remotely impacts others, and the injured organs synergistically worsen outcomes. Recently, several mediators, including extracellular histones and neutrophil extracellular traps, were identified as contributors to distant organ damage. This study aimed to elucidate whether these mediators play a crucial role in remote organ damage induced by intestinal ischemia–reperfusion. This study also aimed to evaluate the protective effects of recombinant thrombomodulin, which has been reported to neutralize extracellular histones, on multiple-organ dysfunction after intestinal ischemia–reperfusion.

Methods

Intestinal ischemia was induced in male C57BL/6J mice via clamping of the superior mesenteric artery. Recombinant thrombomodulin (10 mg/kg) was administered intraperitoneally with the initiation of reperfusion. The mice were subjected to a survival analysis, histologic injury scoring, quantitative polymerase chain reaction analysis of tumor necrosis factor-α and keratinocyte-derived chemokine expression, Evans blue dye vascular permeability assay, and enzyme-linked immunosorbent assay analysis of histones in the jejunum, liver, lung, and kidney after 30- or 45-min ischemia. Neutrophil extracellular trap formation was evaluated by immunofluorescence staining.

Results

Recombinant thrombomodulin yielded statistically significant improvements in survival after 45-min ischemia (ischemia–reperfusion without vs. with 10 mg/kg recombinant thrombomodulin: 0% vs. 33%, n = 21 per group, P = 0.001). Recombinant thrombomodulin reduced the histologic injury score, expression of tumor necrosis factor-α and keratinocyte-derived chemokine, and extravasation of Evans blue dye, which were augmented by 30-min ischemia–reperfusion, in the liver, but not in the intestine. Accumulated histones and neutrophil extracellular traps were found in the livers and intestines of 30-min ischemia–reperfusion–injured mice. Recombinant thrombomodulin reduced these accumulations only in the liver.

Conclusions

Recombinant thrombomodulin improved the survival of male mice with intestinal ischemia–reperfusion injury. These findings suggest that histone and neutrophil extracellular trap accumulation exacerbate remote liver injury after intestinal ischemia–reperfusion. Recombinant thrombomodulin may suppress these accumulations and attenuate liver injury.

Dendritic cell subsets and locations

Dendritic cells (DCs) are a unique class of immune cells that act as a bridge between innate and adaptive immunity. The discovery of DCs by Cohen and Steinman in 1973 laid the foundation for DC biology, and the advances in the field identified different versions of DCs with unique properties and functions. DCs originate from hematopoietic stem cells, and their differentiation is modulated by Flt3L. They are professional antigen-presenting cells that patrol the environmental interphase, sites of infection, or infiltrate pathological tissues looking for antigens that can be used to activate effector cells. DCs are critical for the initiation of the cellular and humoral immune response and protection from infectious diseases or tumors. DCs can take up antigens using specialized surface receptors such as endocytosis receptors, phagocytosis receptors, and C type lectin receptors. Moreover, DCs are equipped with an array of extracellular and intracellular pattern recognition receptors for sensing different danger signals. Upon sensing the danger signals, DCs get activated, upregulate costimulatory molecules, produce various cytokines and chemokines, take up antigen and process it and migrate to lymph nodes where they present antigens to both CD8 and CD4 T cells. DCs are classified into different subsets based on an integrated approach considering their surface phenotype, expression of unique and conserved molecules, ontogeny, and functions. They can be broadly classified as conventional DCs consisting of two subsets (DC1 and DC2), plasmacytoid DCs, inflammatory DCs, and Langerhans cells.

Mannose-Binding Lectin Drives Platelet Inflammatory Phenotype and Vascular Damage After Cerebral Ischemia in Mice via IL (Interleukin)-1α

Supplemental Digital Content is available in the text.

Objective—

Circulating complement factors are activated by tissue damage and contribute to acute brain injury. The deposition of MBL (mannose-binding lectin), one of the initiators of the lectin complement pathway, on the cerebral endothelium activated by ischemia is a major pathogenic event leading to brain injury. The molecular mechanisms through which MBL influences outcome after ischemia are not understood yet.

Approach and Results—

Here we show that MBL-deficient (MBL^−/−) mice subjected to cerebral ischemia display better flow recovery and less plasma extravasation in the brain than wild-type mice, as assessed by in vivo 2-photon microscopy. This results in reduced vascular dysfunction as shown by the shift from a pro- to an anti-inflammatory vascular phenotype associated with MBL deficiency. We also show that platelets directly bind MBL and that platelets from MBL^−/− mice have reduced inflammatory phenotype as indicated by reduced IL-1α (interleukin-1α) content, as early as 6 hours after ischemia. Cultured human brain endothelial cells subjected to oxygen-glucose deprivation and exposed to platelets from MBL^−/− mice present less cell death and lower CXCL1 (chemokine [C-X-C motif] ligand 1) release (downstream to IL-1α) than those exposed to wild-type platelets. In turn, MBL deposition on ischemic vessels significantly decreases after ischemia in mice treated with IL-1 receptor antagonist compared with controls, indicating a reciprocal interplay between MBL and IL-1α facilitating endothelial damage.

Conclusions—

We propose MBL as a hub of pathogenic vascular events. It acts as an early trigger of platelet IL-1α release, which in turn favors MBL deposition on ischemic vessels promoting an endothelial pro-inflammatory phenotype.

The role of vascular smooth muscle cell membrane-bound thrombomodulin in neointima formation

BACKGROUND AND AIMS

Thrombomodulin (TM) is an endothelial cell membrane-bound anticoagulant protein expressed in normal arteries. After vascular injury, medial and neointimal smooth muscle cells (SMCs) exhibit large amounts of TM. The purpose of this study was to investigate the physiological significance of vascular SMC-bound TM.

METHODS

The morphology, expression of phenotype markers and cell behaviors of cultured aortic SMCs after knockdown of TM were observed. Transgenic mice with SMC-specific TM deletion were generated, and carotid neointima formation was induced by carotid ligation.

RESULTS

Cultured human aortic SMCs displayed a synthetic phenotype with a rhomboid-shaped morphology and expressed TM. TM knockdown induced a spindle-shaped change in morphology with an increased expression of contractile phenotype marker and decreased expression of synthetic phenotype marker. TM knockdown not only attenuated the proliferation of SMCs but also reduced tumor necrosis factor-α-induced nuclear factor-κB activation and interlukin-6 production. In a carotid artery ligation model, transgenic mice with SMC-specific TM deletion (SM22-cre^tg/TM^flox/flox) had significantly less cellular proliferation in arterial walls compared with wild type mice (SM22-cre^tg/TM^+/+). The neointima area and neointima/media area ratio were smaller in SM22-cre^tg/TM^flox/flox mice at 4 weeks after ligation.

CONCLUSIONS

Our results indicate that vascular SMC-bound TM plays a role in changes of the SMC phenotype. It also influences SMC cell behavior and injury-induced neointima formation.

Recombinant human soluble thrombomodulin ameliorates acetaminophen-induced liver toxicity in mice

Recombinant human soluble thrombomodulin alpha (rhTM) has been developed as an anticoagulant with anti-inflammatory activity. Notably, acetaminophen (APAP) -induced liver disease (AILI) is caused by direct metabolite-induced hepatotoxicity as well as hepatic hyper-coagulation. To evaluate the utility of anticoagulant for the treatment of AILI, rhTM was administered in a mouse AILI model and liver damage was analyzed. AILI was induced in 8-week-old mice by intraperitoneal injection of APAP. rhTM (20 mg/kg) or placebo was injected at the same time as APAP administration. Serum alanine aminotransferase, fibrin degradation products and high-mobility group box 1 levels were significantly decreased in the rhTM-treated group compared with the control group. Furthermore, rhTM reduced the necrotic area and fibrin deposition in liver sections. rhTM suppressed the mRNA expression of heme oxygenase-1, plasminogen activator inhibitor type-1, tissue factors, and inflammatory cytokines compared with the control group. rhTM did not change the hepatic GSH content at 2 h after APAP injection, but restored them at 4 h after the insult. rhTM ameliorated liver damage in mice with AILI, probably via the improvement in liver perfusion induced by it's anticoagulant acitivity, which can lead to the suppression of secondary liver damage.

Therapeutic Role of Recombinant Human Soluble Thrombomodulin for Acute Exacerbation of Idiopathic Pulmonary Fibrosis

Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is an acute respiratory worsening of unidentifiable cause that sometimes develops during the clinical course of IPF. Although the incidence of AE-IPF is not high, prognosis is poor. The pathogenesis of AE-IPF is not well understood; however, evidence suggests that coagulation abnormalities and inflammation are involved. Thrombomodulin is a transmembranous glycoprotein found on the cell surface of vascular endothelial cells. Thrombomodulin combines with thrombin, regulates coagulation/fibrinolysis balance, and has a pivotal role in suppressing excess inflammation through its inhibition of high-mobility group box 1 protein and the complement system. Thus, thrombomodulin might be effective in the treatment of AE-IPF, and we and other groups found that recombinant human soluble thrombomodulin improved survival in patients with AE-IPF. This review summarizes the existing evidence and considers the therapeutic role of thrombomodulin in AE-IPF.

Role of extracellular vesicles in the development of sepsis-induced coagulopathy

Background

The advances of research on extracellular vesicles (EVs) are of particular interest to the clinicians as well as the researchers who are studying coagulation disorder in sepsis. Here, we intend to update the latest knowledge and currently unsolved problems that should be addressed.

Main body

Secreted membrane-enclosed vesicles including apoptotic bodies, exosomes, ectosomes, microvesicles, and microparticles are generically called EVs. Though the basic structure of these vesicles is the same, i.e., originating from the plasma membrane, their characteristics differ significantly depending on their surface structures and interior components. Numerous studies have shown elevated levels of circulating EVs that exhibit proinflammatory and procoagulant properties during sepsis. These EVs are known to play important roles in the development of coagulation disorder and organ dysfunction in sepsis. Coagulation disorder in sepsis is characterized by activated coagulation, disrupted anticoagulant systems, and imbalanced fibrinolytic systems. These processes collaborate with one another and contribute to the development of disseminated intravascular coagulation (DIC), with devastating consequences. As part of this pathogenesis, the membrane-exposed tissue factor, phosphatidylserine and bioactive substances contained within the vesicles, such as histones, nucleosomes, and high-mobility group box 1, contribute to the development of DIC. EVs not only upregulate the procoagulant systems by themselves, but they also disseminate prothrombotic activities by transferring their procoagulant properties to distant target cells. Though the basic concept behind the role of procoagulant properties, EVs in the development of sepsis-induced coagulopathy has started to be unveiled, knowledge of the actual status is far from satisfactory, mainly because of the lack of standardized assay procedures. Recent advances and current problems that remain to be resolved are introduced in this review.

Conclusion

The recent studies succeeded to elucidate the important roles of EVs in the progress of coagulation disorder in sepsis. However, further harmonization in terminology, methodology, and evaluation methods is required for future studies.

Human dendritic cell subsets: an update

Dendritic cells (DC) are a class of bone-marrow-derived cells arising from lympho-myeloid haematopoiesis that form an essential interface between the innate sensing of pathogens and the activation of adaptive immunity. This task requires a wide range of mechanisms and responses, which are divided between three major DC subsets: plasmacytoid DC (pDC), myeloid/conventional DC1 (cDC1) and myeloid/conventional DC2 (cDC2). Each DC subset develops under the control of a specific repertoire of transcription factors involving differential levels of IRF8 and IRF4 in collaboration with PU.1, ID2, E2-2, ZEB2, KLF4, IKZF1 and BATF3. DC haematopoiesis is conserved between mammalian species and is distinct from monocyte development. Although monocytes can differentiate into DC, especially during inflammation, most quiescent tissues contain significant resident populations of DC lineage cells. An extended range of surface markers facilitates the identification of specific DC subsets although it remains difficult to dissociate cDC2 from monocyte-derived DC in some settings. Recent studies based on an increasing level of resolution of phenotype and gene expression have identified pre-DC in human blood and heterogeneity among cDC2. These advances facilitate the integration of mouse and human immunology, support efforts to unravel human DC function in vivo and continue to present new translational opportunities to medicine.

Significant common environmental effects on leukocyte subpopulations

Major efforts are invested in the analysis of phenotypic variation in a population of individuals. While many of these studies focus on the genetic basis of phenotypic variation via measurements of DNA polymorphic sites, the environmental effects are still elusive. Here we propose a methodology, called CCCE ('Cell Composition Common Environment'), to identify environmental effects on the composition of immune cell functionalities. Specifically, CCCE is focused on the common experiences that are shared between siblings (the 'common environment'), designed to correct for cell subpopulation heterogeneity, and is based on a multicolor flow cytometry analysis across a large cohort of human monozygotic and dizygotic twins. We demonstrate that the CCCE methodology can provide insights on the relations between common environmental effects and the heterogenic functions of several immune cell types, such as NK cells effector functions and coagulation-related capabilities of monocytes. The software described in this article is available at http://csgi.tau.ac.il/CCCE.

Utility of Viscoelastic Assays Beyond Coagulation: Can Preoperative Thrombelastography Indices Predict Tumor Histology, Nodal Disease, and Resectability in Patients Undergoing Pancreatectomy?

BACKGROUND

Hypercoagulability and malignancy have been linked since the 1860s. However, the impact of different neoplasms on multiple components of the coagulation system remains poorly understood. Thrombelastography (TEG) enables measurement of coagulation incorporating clotting through fibrinolysis. We hypothesize that specific TEG indices that are associated with hypercoagulability can be appreciated in patients with adenocarcinoma undergoing pancreatic resection.

STUDY DESIGN

Blood samples were obtained from patients undergoing pancreatic resection before surgical incision and assayed with TEG. The 4 indices of coagulation measured by TEG included in the analysis were R time, angle, maximum amplitude, and lysis at 30 minutes. Patient tumor type, nodal disease, and mass resectability were contrasted with TEG indices.

RESULTS

One hundred patients were enrolled over 18 months. The majority (63%) of patients had adenocarcinoma. Patients with adenocarcinoma had increased angle compared with other lesions (49 degrees [interquartile range {IQR} 37 to 59 degrees] vs 43 degrees [IQR 32 to 49 degrees]; p = 0.011). When excluding patients that underwent neoadjuvant therapy, patients with adenocarcinoma had shorter R times (13 minutes [IQR 9 to 16 minutes] vs 14 minutes [IQR 12 to 18 minutes]; p = 0.051), steeper angles (49 degrees [IQR 40 to 59 degrees] vs 43 degrees [IQR 32 to 49 degrees]; p = 0.010), and higher maximum amplitude (67 mm [IQR 61 to 69 mm] vs 62 mm [IQR 57 to 67 mm]; p = 0.017). Nodal disease was associated with a significantly increased angle (49 degrees [IQR 42 to 59 degrees] vs 40 degrees [IQR 32 to 50 degrees]; p = 0.002) and maximum amplitude (64 mm [IQR 61 to 69 mm] vs 62 mm [IQR 56 to 67 mm]; p = 0.017). Patients who underwent successful mass resection had longer R times (14 minutes [IQR 11 to 17 minutes] vs 10 minutes [IQR 9 to 15]; p = 0.033) and shorter angles (44 degrees [IQR 35 to 55 degrees] vs 58 degrees [IQR 45 to 66 degrees]; p = 0.025).

CONCLUSIONS

Patients with adenocarcinoma undergoing pancreatic resection have multiple TEG abnormalities consistent with hypercoagulability. These TEG outputs are associated with tumor type, nodal disease, and probability of a successful resection. The use of preoperative TEG has the potential to aid surgeon and patient discussions on anticipated disease burden and prognosis before resection.

Recombinant human soluble thrombomodulin as an anticoagulation therapy improves recurrent miscarriage and fetal growth restriction due to placental insufficiency - The leading cause of preeclampsia

INTRODUCTION

Placental insufficiency is one of the major risk factors for growth restriction and preeclampsia. The aim of this study is to investigate whether recombinant human Thrombomodulin(r-TM) improves fetal conditions and physiological outcomes.

METHODS

We used CBA/J × BALB/C mice as a control and CBA/J × DBA/2 mice - a well-studied model of recurrent spontaneous miscarriage. Pregnant mice received daily subcutaneous injections of r-TM or saline from day 0-15. The fetal resorption rate, fetal weight, and litter size were calculated at day 15. Additionally, we analyzed the mRNA expression of angiogenic factors and the concentration of soluble Flt-1 (sFlt-1) using the ELISA kit.

RESULTS

The rate of fetal resorption in CBA/J × DBA/2 mice treated with r-TM was significantly lower compared with mice without r-TM treatment. Additionally, fetal weight and litter size were also significantly higher in the r-TM treated mice. Fibrinogen deposition in the labyrinth area of the CBA/J × DBA/2 mice treated with r-TM was significantly lower compared with deposits in the mice untreated with r-TM. As well, r-TM significantly increased the gene expression level of VEGF and Flt-1 mRNA in the placentas of the CBA/J × DBA/2 mice. r-TM treatment also significantly decreased the production of sFlt-1 protein in the placentas of preeclampsia-like diseased mice.

CONCLUSION

r-TM as an anticoagulation therapy has the potential for the medical treatment of recurrent miscarriage and fetal growth restriction due to improved angiogenic factors. Additionally, r-TM treatment has the potential for the recovery of preeclampsia.

Transcriptional patterns associated with BDCA3 expression on BDCA1+ myeloid dendritic cells

Myeloid dendritic cells, including BDCA3^hi DCs and BDCA1⁺ DCs (hereafter dubbed DC1 and DC2 for clarity), play a pivotal role in the induction and regulation of immune responses. Interestingly, a fraction of DC2 also express low to intermediate levels of BDCA3. It is unknown whether BDCA3⁺ DC2 also share other traits with DC1 that are absent in BDCA3^- DC2 and/or whether BDCA3 expression renders DC2 functionally distinct from their BDCA3-lacking counterparts. Here, we used expression analysis on a predefined set of immunology-related genes to determine divergence between BDCA3-positive and BDCA3-negative DC2 and their relation to bona fide BDCA3^hi DC1. Results showed that mRNA fingerprints of BDCA3⁺ DC2 and BDCA3^- DC2 are very similar, and clearly distinct from that of DC1. Differences in mRNA expression, however, were observed between BDCA3⁺ DC2 and BDCA3^- DC2 that pointed toward a more activated status of BDCA3⁺ DC2. In line with this, higher steady state maturation marker expression and TLR-induced maturation marker expression and inflammatory cytokine production by BDCA3⁺ DC2 were observed. This dataset provides insight into the relationship between myeloid DC populations and contributes to further understanding of DC immunobiology.

High Mobility Group Box-1 (HMGb1): Current Wisdom and Advancement as a Potential Drug Target

High mobility group box-1 (HMGb1) protein, a nuclear non-histone protein that is released or secreted from the cell in response to damage or stress, is a sentinel for the immune system that plays a critical role in cell survival/death pathways. This review highlights key features of the endogenous danger-associated molecular pattern (DAMP) protein, HMGb1 in the innate inflammatory response along with various cofactors and receptors that regulate its downstream effects. The evidence demonstrating increased levels of HMGb1 in human inflammatory diseases and conditions is presented, along with a summary of current small molecule or peptide-like antagonists proven to specifically target HMGb1. Additionally, we delineate the measures needed toward validating this protein as a clinically relevant biomarker or bioindicator and as a relevant drug target.

Thrombomodulin favors leukocyte microvesicle fibrinolytic activity, reduces NETosis and prevents septic shock-induced coagulopathy in rats

BACKGROUND

Septic shock-induced disseminated intravascular coagulation is responsible for increased occurrence of multiple organ dysfunction and mortality. Immunothrombosis-induced coagulopathy may contribute to hypercoagulability. We aimed at determining whether recombinant human thrombomodulin (rhTM) could control exaggerated immunothrombosis by studying procoagulant responses, fibrinolysis activity borne by microvesicles (MVs) and NETosis in septic shock.

METHODS

In a septic shock model after a cecal ligation and puncture-induced peritonitis (H0), rats were treated with rhTM or a placebo at H18, resuscitated and monitored during 4 h. At H22, blood was sampled to perform coagulation tests, to characterize MVs and to detect neutrophils extracellular traps (NETs). Lungs were stained with hematoxylin-eosin for inflammatory injury assessment.

RESULTS

Coagulopathy was attenuated in rhTM-treated septic rats compared to placebo-treated rats, as attested by a significant decrease in procoagulant annexin A5+-MVs and plasma procoagulant activity of phospholipids and by a significant increase in antithrombin levels (84 ± 8 vs. 64 ± 6%, p < 0.05), platelet count (582 ± 157 vs. 319 ± 91 × 109/L, p < 0.05) and fibrinolysis activity borne by MVs (2.9 ± 0.26 vs. 0.48 ± 0.29 U/mL urokinase, p < 0.05). Lung histological injury score showed significantly less leukocyte infiltration. Decreased procoagulant activity and lung injury were concomitant with decreased leukocyte activation as attested by plasma leukocyte-derived MVs and NETosis reduction after rhTM treatment (neutrophil elastase/DNA: 93 ± 33 vs. 227 ± 48 and citrullinated histones H3/DNA: 96 ± 16 vs. 242 ± 180, mOD for 109 neutrophils/L, p < 0.05).

CONCLUSION

Thrombomodulin limits procoagulant responses and NETosis and at least partly restores hemostasis control during immunothrombosis. Neutrophils might thus stand as a promising therapeutic target in septic shock-induced coagulopathy.

THBD sequence variants potentially related to recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a frequently occurring disease, which is classified as idiopathic in more than 50% of cases. THBD, the endothelial cell receptor for thrombin, has been associated with distinct biological processes and considered a coherent RPL-related candidate gene. In the present study, we have sequenced the complete coding region of THBD in 262 patients affected by RPL. Bioinformatics analysis and screening of controls strongly suggested that the THBD-p.Trp153Gly mutation might be related to RPL aetiology. It could be used, after its validation by functional assays, as a molecular marker for diagnostic/prognostic purposes.