Transforming growth factor-β receptor type 2 is required for heparin-binding protein-induced acute lung injury and vascular leakage for transforming growth factor-β/Smad/Rho signaling pathway activation

C5a/C5aR regulates Th1/Th2 imbalance in sepsis-associated lung injury by promoting neutrophil activation to increase PAD4 expression

OBJECTIVE

Multi-organ failure frequently complicates sepsis, with lungs being the primary target. T helper (Th) cell activation and phenotypic imbalance among them contribute significantly to sepsis-associated lung injury. Additionally, the complement system could regulate the polarized phenotype of T lymphocytes. Therefore, this study investigated the effect of C5a/C5a receptor (C5aR)/Peptidylarginine deiminase 4 (PAD4) on the Th1/Th2 ratio in sepsis-induced lung injury.

METHODS

ELISA was used to detect the expression of PAD4, HBP, MPO, IL-1β, IL-10, IL-6, IL-4, syndecan-1, endocan and H3Cit. An LPS-induced septic lung injury mouse model was constructed, with HE and PAS stains evaluating lung damage. BCA kit quantified BALF total protein, Western blot examined C5aR, syndecan-1, endocan, PAD4 levels, while TUNEL and flow cytometry assessed tissue cellular apoptosis. Furthermore, flow cytometry was used to detect the +Th1 and Th2 cells proportion in peripheral blood, and CCK-8 was used to detect BEAS-2B activity.

RESULTS

The results indicated that PAD4 and inflammatory factors were increased in lesion samples compared with controls. In sepsis-induced lung injury mice, addition of GSK484, a PAD4 inhibitor, effectively alleviated sepsis-induced lung edema and inflammatory responses. GSK484 was found to inhibit C5a/C5aR expression and suppress apoptosis and lung injury. Furthermore, GSK484 markedly inhibited Th1 cell phenotypes in vitro. Additionally, GSK484 intervention on Th1 cell phenotype further affected lung epithelial cell injury.

CONCLUSION

In summary, we revealed the mechanism of C5a/C5aR-induced PAD4 upregulation via neutrophil activation in sepsis-associated lung injury, causing a Th1/Th2 imbalance and lung injury, providing a novel approach for sepsis-associated lung injuries treatment.

Neutrophil-derived heparin-binding protein increases endothelial permeability in acute lung injury by promoting TRIM21 and the ubiquitination of P65

Acute lung injury (ALI), which poses a significant public health threat, is commonly caused by sepsis. ALI is associated with permeability and glycolysis changes in pulmonary microvascular endothelial cells. Our study demonstrates that heparin-binding protein (HBP), released from neutrophils during sepsis, exacerbates endothelial permeability and glycolysis, thereby triggering ALI. Through coimmunoprecipitation and mass spectrometry, TRIM21 was identified as a HBP interaction partner. Notably, HBP enhances the protein stability of TRIM21 by inhibiting K48 ubiquitination. TRIM21 binds to and promotes K63-linked ubiquitination of P65, facilitating its nuclear translocation. TRIM21 regulates HPMEC permeability and glycolysis in a manner dependent on P65 nuclear translocation. HBP stabilizes TRIM21 and enhances TRIM21 interactions with P65. Rescue experiments conducted in vivo and in vitro demonstrate that modulation of endothelial permeability and glycolysis by HBP is predominantly mediated through the TRIM21-P65 axis. Our results suggest that targeting the HBP/TRIM21/P65 axis is a novel therapeutic strategy to ameliorate ALI.

Transfusion-Related Acute Lung Injury: from Mechanistic Insights to Therapeutic Strategies

Transfusion-related acute lung injury (TRALI) is a potentially lethal complication of blood transfusions, characterized by the rapid onset of pulmonary edema and hypoxemia within six hours post-transfusion. As one of the primary causes of transfusion-related mortality, TRALI carries a significant mortality rate of 6-12%. However, effective treatment strategies for TRALI are currently lacking, underscoring the urgent need for a comprehensive and in-depth understanding of its pathogenesis. This comprehensive review provides an updated and detailed analysis of the current landscape of TRALI, including its clinical presentation, pathogenetic hypotheses, animal models, cellular mechanisms, signaling pathways, and potential therapeutic targets. By highlighting the critical roles of these pathways and therapies, this review offers valuable insights to inform the development of preventative and therapeutic strategies and to guide future research efforts aimed at addressing this life-threatening condition.

Analysis of the inflammatory storm response and heparin binding protein levels for the diagnosis and prognosis of sepsis-associated encephalopathy

BACKGROUND

Sepsis-associated encephalopathy (SAE) is a complication of impaired neurologic function during the development of sepsis. Its occurrence is closely related to severe systemic infection. The increase of serum Interleukin 6 kit and other inflammatory cytokines has certain clinical significance in the diagnosis of sepsis, However, there is no research at home or abroad indicating whether the high expression of related inflammatory cytokines (inflammatory cytokine storm, ICS) is valuable for the diagnosis and prognosis of SAE patients.

OBJECTIVES

The aim of this study was to analyze serum inflammatory cytokines 6 kit [IL-2/4/6/10, TNF-α, and gamma interferon (IFN-γ)], heparin-binding protein (HBP), and serum cholinesterase levels and their clinical significance in septic patients. In this study, we defined the values of inflammatory storm (IL-6 > 5000 pg/ml, IL-10 > 1000 pg/ml, and HBP > 300 ng/ml) to analyze the diagnostic value and 28-day prognostic predictive ability of inflammatory cytokine storm and the severity score in SAE patients.

METHODS

A total of 140 patients with sepsis in the ICU and EICU of the Lianyungang First People's Hospital were included in the present study from October 2021 to March 2023. Based on the Diagnostic criteria for SAE, the 140 cases were divided into 62 cases in the SAE group and 78 cases in the non-SAE group. On admission to the ICU/EICU, the patients gender, age, vital signs, and serum levels of various cytokines were recorded. The Glasgow Coma Scale (GCS), Sequential Organ Failure Scale (SOFA), and Acute Physiological and Chronic Health Score II (APACHE-II) scores were also assessed to analyze the risk cytokines for the occurrence of SAE.

RESULTS

The age, Sofa score, APACHE-II score, 28-day mortality rate, serological cellular inflammatory cytokines (IL-2/6/10, INF-α, and interferon-gamma), HBP were significantly higher in the SAE group than in the non-SAE group (P < 0.05). In addition, the GCS score and serum cholinesterase levels in the SAE group were lower than in the non-SAE group (P < 0.05). Subsequently, Multi-factor logistic regression analysis revealed that ultra-high IL-6 (> 5000 pg/ml), IL-10 (> 1000 pg/ml), and HBP (> 300 ng/ml) levels and elevated SOFA and APACHE-II scores were risk cytokines for the development of SAE (P < 0.05). 28-day mortality was significantly higher in patients in the SAE group and in the IL-6 > 5000 pg/ml group compared to patients in the USAE and IL-6 < 5000 pg/ml groups(P < 0.001).The four screened predictors of HBP > 300 ng/ml, IL-6 > 5000 pg/ml, decreased GCS score, and decreased APACHEII score were combined into a new predictive data model (risk score).In the SAE group, patients with high risk scores had a higher 28-day mortality rate compared with the low risk score group (P < 0.001).

CONCLUSIONS

The occurrence of SAE is closely correlated with age, concomitant diabetes, SOFA score, APACHE II score, serum cytosolic inflammatory cytokine levels (IL-2/6/10, TNF-α, and IFN-γ), HBP, and serum cholinesterase levels. In addition, inflammatory storms are associated with the mechanism of SAE, and high expression levels of the inflammatory cytokines IL-6 > 5000 pg/ml, IL-10 > 1000 pg/ml, and HBP > 300 ng/ml in patients with sepsis contribute to the early diagnosis of SAE. In addition, IL-6 > 5000 pg/ml was also associated with an increase in 28-day mortality (P < 0.05), suggesting that the level of inflammatory storms may be related to the mechanism of sepsis-related SAE and 28-day mortality. According to the LASSO results, when SAE patients admitted to the intensive care unit satisfy HBP > 300 ng/ml, IL6 > 5000 pg/ml, decreased GCS score, and increased APACHEII score, it suggests that the patient's 28-day mortality rate is higher, and it also validates that inflammatory storm can be used as a predictor of prognosis for SAE patients.

Heparin in sepsis: current clinical findings and possible mechanisms

Sepsis is a clinical syndrome resulting from the interaction between coagulation, inflammation, immunity and other systems. Coagulation activation is an initial factor for sepsis to develop into multiple organ dysfunction. Therefore, anticoagulant therapy may be beneficial for sepsis patients. Heparin possesses a variety of biological activities, so it has a broad prospect in sepsis. Previous studies suggested that patients with sepsis-induced disseminated intravascular coagulation and high disease severity might be suitable for anticoagulant therapy. With the development of artificial intelligence (AI), recent studies have shown that patients with severe coagulation activation represent the targeted patients for anticoagulant therapy in sepsis. However, it remains necessary to accurately define the relevant biomarkers indicative of this phenotype and validate their clinical utility by large randomized controlled trials (RCTs). Analyses of data from early small RCTs, subgroup analyses of large RCTs and meta-analyses have collectively suggested that anticoagulant therapy, particularly the use of heparin, may be an effective approach for managing sepsis patients. Concurrently, debate persists regarding the optimal selection of anticoagulants, proper timing, usage and dosage of administration that should be employed to assess treatment efficacy. The primary mechanisms of heparin are acting on heparan sulfate, histones, high mobility group box 1 and heparin-binding protein, which interfere with the regulation of inflammation, vascular permeability, coagulation, endothelial function and other biological activities. However, the underlying pathophysiological processes mediating the potential therapeutic effects of heparin in the context of sepsis remain incompletely understood and warrant additional rigorous investigation to establish the mechanism more conclusively.

Heparin-binding protein and sepsis-induced coagulopathy: Modulation of coagulation and fibrinolysis via the TGF-β signalling pathway

BACKGROUND

Heparin-binding protein (HBP) levels have been linked to organ failure and may represent an inflammatory biomarker of sepsis. We found disseminated intravascular coagulation (DIC) is associated with higher HBP levels in patients and in in vivo and in vitro models. This prospective, single-center observational study investigated the effects and underlying mechanisms of HBP on the coagulation cascade in sepsis.

METHODS

538 patients with sepsis from June 2016 to December 2019 were enrolled. Mechanisms underlying HBP and the coagulation system were investigated in human umbilical vein endothelial cells (HUVEC) and C57 mice.

RESULTS

Increased HBP was associated with sepsis-induced DIC. The optimal cutoff value was 37.5 ng/mL (sensitivity: 56 %, specificity: 65 %). Antithrombin-III (AT-III) activity, plasmin-a2 plasmin inhibitor complex (PIC), procalcitonin (PCT), hemoglobin, and HBP ≥37.5 ng/mL were associated with of DIC occurrence. In HUVECs &C57 mice models, Western blotting, qPCR, and immunohistochemistry analysis showed that the binding between HBP and TGF-β receptor 2 (TGFBR2) caused elevation of plasminogen activator inhibitor-1 (PAI-1) levels. Furthermore, we found that mice stimulated with HBP had higher levels of fibrinogen and D-dimer in the blood. HBP treatment caused the accumulation of fibrinogen in mice lung tissue. Treatment with TGFBR2-small interfering RNAs inhibited the effects.

CONCLUSION

Patients with sepsis having HBP ≥37.5 ng/mL at admission were more likely to develop DIC. HBP upregulates the expression of fibrinogen and PAI-1 via TGFBR2 and the TGF-β signalling pathway.

Signaling pathways and potential therapeutic targets in acute respiratory distress syndrome (ARDS)

Acute respiratory distress syndrome (ARDS) is a common condition associated with critically ill patients, characterized by bilateral chest radiographical opacities with refractory hypoxemia due to noncardiogenic pulmonary edema. Despite significant advances, the mortality of ARDS remains unacceptably high, and there are still no effective targeted pharmacotherapeutic agents. With the outbreak of coronavirus disease 19 worldwide, the mortality of ARDS has increased correspondingly. Comprehending the pathophysiology and the underlying molecular mechanisms of ARDS may thus be essential to developing effective therapeutic strategies and reducing mortality. To facilitate further understanding of its pathogenesis and exploring novel therapeutics, this review provides comprehensive information of ARDS from pathophysiology to molecular mechanisms and presents targeted therapeutics. We first describe the pathogenesis and pathophysiology of ARDS that involve dysregulated inflammation, alveolar-capillary barrier dysfunction, impaired alveolar fluid clearance and oxidative stress. Next, we summarize the molecular mechanisms and signaling pathways related to the above four aspects of ARDS pathophysiology, along with the latest research progress. Finally, we discuss the emerging therapeutic strategies that show exciting promise in ARDS, including several pharmacologic therapies, microRNA-based therapies and mesenchymal stromal cell therapies, highlighting the pathophysiological basis and the influences on signal transduction pathways for their use.

The Profiling of 179 miRNA Expression in Serum from Limb Girdle Muscular Dystrophy Patients and Healthy Controls

Limb girdle muscular dystrophies (LGMDs) are a group of genetically inherited neuromuscular diseases with a very variable clinical presentation and overlapping traits. Over the last few years there has been an increasing interest in the use of non-invasive circulating biomarkers to monitor disease progression and to evaluate the efficacy of therapeutic approaches. Our aim was to identify the miRNA signature with potential value for LGMD patient screening and stratification. Using miRCURY LNA miRNA qPCR Serum/Plasma Panel, we analyzed 179 miRNAs from 16 patients, divided in four pools based on their genetic diagnosis, and from healthy controls. The miRNAs analysis showed a total of 107 dysregulated miRNAs in LGMD patients when compared to the healthy controls. After filtering via skeletal tissue expression and gene/pathways target analysis, the number of dysregulated miRNAs drastically reduced. Six selected miRNAs-let-7f-5p (in LGMDR1), miR-20a-5p (in LGMDR2), miR-130b-5p, miR-378a-5p (both in LGMDR3), miR-376c-3p and miR-382-5p (both in LGMDR4)-whose expression was significantly lower compared to controls in the different LGMD pools, were further investigated. The bioinformatic analysis of the target genes in each selected miRNA revealed ECM-receptor interaction and TGF-beta signaling as the most involved pathways. The correlation analysis showed a good correlation of let-7f-5p with fibrosis and with the cross sectional area of type I and type II fibers, while miR-130b-5p showed a good correlation with the age of onset of the disease. The receiver operating characteristic curves showed how single miRNAs were able to discriminate a specific group of LGMD patients and how the combination of six miRNAs was able to discriminate LGMD patients from controls.