CTGF promotes the repair and regeneration of alveoli after acute lung injury by promoting the proliferation of subpopulation of AEC2s.

BACKGROUND: Functional alveolar regeneration is essential for the restoration of normal lung homeostasis after acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Lung is a relatively quiescent organ and a variety of stem cells are recruited to participate in lung repair and regeneration after lung tissue injury. However, there is still no effective method for promoting the proliferation of endogenous lung stem cells to promote repair and regeneration. METHODS: Using protein mass spectrometry analysis, we analyzed the microenvironment after acute lung injury. RNA sequencing and image cytometry were used in the alveolar epithelial type 2 cells (AEC2s) subgroup identification. Then we used Sftpc+AEC2 lineage tracking mice and purified AEC2s to further elucidate the molecular mechanism by which CTGF regulates AEC2s proliferation both in vitro and in vivo. Bronchoalveolar lavage fluid (BALF) from thirty ARDS patients who underwent bronchoalveolar lavage was collected for the analysis of the correlation between the expressing of Krt5 in BALF and patients' prognosis. RESULTS: Here, we elucidate that AEC2s are the main facultative stem cells of the distal lung after ALI and ARDS. The increase of connective tissue growth factor (CTGF) in the microenvironment after ALI promoted the proliferation of AEC2s subpopulations. Proliferated AEC2s rapidly expanded and differentiated into alveolar epithelial type 1 cells (AEC1s) in the regeneration after ALI. CTGF initiates the phosphorylation of LRP6 by promoting the interaction between Krt5 and LRP6 of AEC2s, thus activating the Wnt signaling pathway, which is the molecular mechanism of CTGF promoting the proliferation of AEC2s subpopulation. CONCLUSIONS: Our study verifies that CTGF promotes the repair and regeneration of alveoli after acute lung injury by promoting the proliferation of AEC2s subpopulation.

Cytokine Biomarker Phenotype for Early Prediction and Triage of Sepsis in Blunt Trauma Patients.

BACKGROUND: Altered levels of inflammatory markers secondary to severe trauma present a major problem to physicians and are prone to interfering with the clinical identification of sepsis events. This study aimed to establish the profiles of cytokines in trauma patients to characterize the nature of immune responses to sepsis, which might enable early prediction and individualized treatments to be developed for targeted intervention. METHODS: A 15-plex human cytokine magnetic bead assay system was used to measure analytes in citrated plasma samples. Analysis of the kinetics of these cytokines was performed in 40 patients with severe blunt trauma admitted to our trauma center between March 2016 and February 2017, with an Injury Severity Score (ISS) greater than 20 with regard to sepsis (Sepsis-3) over a 14-d time course. RESULTS: In total, the levels of six cytokines were altered in trauma patients across the 1-, 3-, 5-, 7-, and 14-d time points. Additionally, IL-6, IL-10, IL-15, macrophage derived chemokine (MDC), GRO, sCD40 L, granulocyte colony-stimulating factor (G-CSF), and fibroblast growth factor (FGF)-2 levels could be used to provide a significant discrimination between sepsis and nonsepsis patients at day 3 and afterward, with an area under the curve (AUC) of up to 0.90 through a combined analysis of the eight biomarkers (P < 0.001). Event-related analysis demonstrated 1.5- to 4-fold serum level changes for these cytokines within 72 h before clinically apparent sepsis. CONCLUSIONS: Cytokine profiles demonstrate a high discriminatory ability enabling the timely identification of evolving sepsis in trauma patients. These abrupt changes enable sepsis to be detected up to 72 h before clinically overt deterioration. Defining cytokine release patterns that distinguish sepsis risk from trauma patients might enable physicians to initiate timely treatment and reduce mortality. Large prospective studies are needed to validate and operationalize the findings. TRIAL REGISTRATION: Clinicaltrials, NCT01713205. Registered October 22, 2012, https://register. CLINICALTRIALS: gov/NCT01713205.

A New Method for Programmable RNA Editing Using CRISPR Effector Cas13X.1.

Type VI CRISPR-Cas13 is the only CRISPR system that can bind and cleave RNA without DNase activity. We used the newly discovered, smaller Cas13X.1 protein to construct an editing system in mammalian cells, aiming to break the delivery restrictions of CRISPR-Cas13 system in vivo and promote the application of Cas13X system in clinical therapy. We employed exogenous fluorescence reporter gene mCherry and endogenous gene transketolase (TKT) closely related to cancer cell metabolism as target genes to evaluate the Cas13X.1 system. The recombinant plasmids targeting exogenous gene mCherry and endogenous gene TKT were constructed based on Cas13X.1 backbone plasmid. The editing efficiency, protein expression level, downstream gene transcript level and safety of Cas13X.1 system were evaluated. Both TKT transcripts of endogenous genes and mCherry transcripts of exogenous genes were significantly degraded by Cas13X.1 system with a knockdown efficiency up to 50%. At the same time, Cas13X.1 down-regulated the expression of the corresponding protein level in the editing of transcripts. In addition, the transcripts of key metabolic enzymes related to TKT were also down-regulated synchronously, suggesting that the degradation of TKT transcripts by Cas13X.1 system affected the main metabolic pathways related to TKT. The morphology, RNA integrity and apoptosis of cells loaded with Cas13X.1 system were not affected. The Cas13X.1 system we constructed had strong RNA knockdown ability in mammalian cells with low cellular toxicity. Compared with other CRISPR-Cas13 systems, Cas13X.1 system with smaller molecular weight has more advantages in vivo delivery. The Cas13X.1 system targeting TKT transcripts also provides an alternative method for the study of anti-cancer therapy.

MiR-608 Exerts Anti-inflammatory Effects by Targeting ELANE in Monocytes.

miR-608 has been indicated to play an important role in the pathogenesis of various inflammation-related diseases, including sepsis and several types of cancers. However, there is little information about the underlying mechanism, especially in inflammatory cells. In this study, an hsa-miR-608-inhibition cell model was constructed in U937 cells using a lentivirus, and gene expression profiles were determined by a cDNA microarray. Altogether, 682 genes showed a difference greater than 1.2-fold, including 184 genes downregulated and 498 genes upregulated. Among these genes, one potential miR-608-target gene, ELANE, was further investigated. A positive relationship between the expression of miR-608 and that of ELANE was found both in vivo and in vitro. In addition, decreased expression of miR-608 resulted in overexpression of ELANE at both the mRNA and protein levels. Cotransfection of HEK293T cells with a miR-608 mimic inhibited reporter activity, and mutation of the miRNA seed sequences abolished the repression of reporter activity. These results suggest that miR-608 is an important posttranscriptional regulator of ELANE expression in human monocytes and may play an important role in the process of inflammation. miR-608 and neutrophil elastase may be novel targets for the diagnosis or treatment of sepsis.

The Hippo-YAP pathway regulates the proliferation of alveolar epithelial progenitors after acute lung injury.

Regeneration of pulmonary epithelial cells plays an important role in the recovery of acute lung injury (ALI), which is defined by pulmonary epithelial cell death. However, the mechanism of the regenerative capacity of alveolar epithelial cells is unknown. Using a lung injury mouse model induced by hemorrhagic shock and lipopolysaccharide, a protein mass spectrometry-based high-throughput screening and linage tracing technology to mark alveolar epithelial type 2 cells (AEC2s), we analyzed the mechanism of alveolar epithelial cells proliferation. We demonstrated that the expression of Hippo-yes-associated protein 1 (YAP1) key proteins were highly consistent with the regularity of the proliferation of alveolar epithelial type 2 cells after ALI. Furthermore, the results showed that YAP1+ cells in lung tissue after ALI were mainly Sftpc lineage-labeled AEC2s. An in vitro proliferation assay of AEC2s demonstrated that AEC2 proliferation was significantly inhibited by both YAP1 small interfering RNA and Hippo inhibitor. These findings revealed that YAP functioned as a key regulator to promote AEC2s proliferation, with the Hippo signaling pathway playing a pivotal role in this process.

Enhancer polymorphism rs10865710 associated with traumatic sepsis is a regulator of PPARG gene expression.

BACKGROUND: Peroxisome proliferator-activated receptor gamma (PPARγ) is a major regulator in sepsis. Our previous study identified the enhancer polymorphism rs10865710C/G to be associated with susceptibility to sepsis in trauma patients. We performed two-stage cohort studies integrating biological experiments of potential functional variants that modify susceptibility to traumatic sepsis. METHODS: Improved multiplex ligation detection reaction (iMLDR) was used to genotype rs10865710 in 797 Han Chinese trauma patients in Chongqing. Clinical relevance was validated in 334 patients in Guizhou. The potential function of rs10865710 in transcriptional regulation was explored through a dual luciferase reporter assay and electrophoretic mobility shift assay (EMSA). Expression of PPARγ was assessed by expression quantitative trait locus (e-QTL) and western blot analyses. RESULTS: The association results confirmed rs10865710 to be significantly strongly associated with sepsis risk in trauma patients of the Chongqing and Guizhou cohorts (OR = 1.41 (1.11-1.79), P = 0.004 and OR = 1.45 (1.01-2.09), P = 0.046, both for allele-dose effect, respectively). A meta-analysis of both cohorts and a previous study indicated strong evidence for this association (OR = 1.41 (1.17-1.71), P = 0.0004 for the dominant model, OR = 1.78 (1.34-2.36), P < 0.0001 for the recessive model and OR = 1.38 (1.20-1.58), P < 0.0001 for the allelic model). Functional experiments verified that rs10865710 was a causative variant influencing enhancer activity (G vs. C, 0.068 ± 0.004 vs. 0.096 ± 0.002, P = 0.0005) and CREB2 binding. Expression analysis also indicatevd rs10865710 genotypes to be associated with levels of PPARγ expression (P = 9.2 × 10-5 for dominant effect and P = 0.005 for recessive effect). CONCLUSIONS: Our study provides evidence that the enhancer-region polymorphism rs10865710 might influence transcription factor binding and regulate PPARγ expression, thus conferring susceptibility to traumatic sepsis. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01713205. Registered 18 October 2012, retrospectively registered.

Host genetic variants in sepsis risk: a field synopsis and meta-analysis.

BACKGROUND: Published data revealed that host genetic variants have a substantial influence on sepsis susceptibility. However, the results have been inconsistent. We aimed to systematically review the published studies and quantitatively evaluate the effects of these variants on the risk of sepsis. METHODS: We searched the PubMed, EMBASE, Medline, Web of Knowledge, and HuGE databases to identify studies that investigated the associations between genetic variants and sepsis risk. Then, we conducted meta-analyses of the associations for genetic variants with at least three study populations and applied the Venice criteria to assess the association result credibility. RESULTS: A literature search identified 349 eligible articles that investigated 405 variants of 172 distinct genes. We performed 204 primary and 185 subgroup meta-analyses for 76 variants of 44 genes. The results showed that 29 variants of 23 genes were significantly associated with the risk of sepsis, including 8 variants of pattern recognition receptors (PRRs), 14 variants of cytokines, one variant of an immune-related gene and 6 variants of other genes. Furthermore, the cumulative epidemiological evidence of a significant association between each variant and the risk of sepsis was classified as strong or moderate for 18 variants. For the 329 variants with fewer than three study populations, 63 variants of 48 genes have been reported to be significantly associated with the risk of sepsis in a systematic review. CONCLUSION: We identified several genetic variants that could influence the susceptibility to sepsis by systematic review and meta-analysis. This study provides a comprehensive overview of the genetic architecture of variants involved in sepsis susceptibility and novel insight that may affect personalized targeted treatment in the future clinical management of sepsis.

The cellular kinetics of lung alveolar epithelial cells and its relationship with lung tissue repair after acute lung injury.

BACKGROUND: Organ regeneration in mammals is hypothesized to require a functional pool of stem or progenitor cells, but the role of these cells in lung regeneration is unknown. METHODS: Based on the fact that postnatal regeneration of alveolar tissue has been attributed to alveolar epithelial cells, we established a hemorrhagic shock and Lipopolysaccharide (LPS) lung injury model. Using this model, we analyzed the cellular kinetics of lung alveolar epithelial cells. RESULTS: The results showed that alveolar epithelium type 2 cells (AEC2s) are damage resistant during acute lung injury, they might be the main cells involved in lung injury and repair. Then we observed the relationship between the expression of HGF, c-Met following ALI in rat lung and proliferation of AEC2s. The proliferation of AEC2s was inhibited when isolated primary AEC2s were co-cultured with c-Met inhibitor SU11274. Furthermore, the numbers of AEC2s was significantly decreased when ALI rats were administrated with SU11274 in vivo. It provided further evidence that the HGF/c-Met signaling plays a vital role in ALI-induced AEC2s proliferation. CONCLUSIONS: AEC2s are damage resistant during acute lung injury and the HGF/c-Met signaling pathway is of vital importance in the proliferation of AEC2s after ALI.

Rs1800625 in the receptor for advanced glycation end products gene predisposes to sepsis and multiple organ dysfunction syndrome in patients with major trauma.

INTRODUCTION: The receptor for advanced glycation end products (RAGE) is a transmembrane receptor of the immunoglobulin superfamily, it plays pivotal roles in the pathogenesis of sepsis in several ways. Our previous study showed that rs1800625 (-429T/C) revealed a strong clinical relevance with sepsis morbidity rate and multiple organ dysfunction syndrome (MODS) in patients with major trauma. In this study, we enlarged the sample size, added two validation populations and examined the expression of RAGE on the surface of peripheral leukocytes to ex vivo lipopolysaccharide (LPS) stimulation in subjects with different genotypes. METHODS: Rs1800625 was genotyped using pyrosequencing in 837 Chinese Han patients with major trauma in Chongqing. We then validated the clinical relevance in 340 Zhejiang and 347 Yunnan patients. The expression of RAGE on the surface of peripheral blood mononuclear cells was measured by flow cytometric analysis. RESULTS: The results indicated that rs1800625 was significantly associated with sepsis morbidity rate and MODS in patients with major trauma in the Chongqing, Zhejiang and Yunnan districts. Patients with CC genotype had lower sepsis morbidity rate and MODS after major trauma. Furthermore, patients with CC genotype had significantly higher RAGE expression (P = 0.009). CONCLUSIONS: The rs1800625 polymorphism is a functional single nucleotide polymorphism and confers host susceptibility to sepsis and MODS in patients with major trauma.

An integrative model with HLA-DR, CD64, and PD-1 for the diagnostic and prognostic evaluation of sepsis.

BACKGROUND: Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection and progressive immunosuppression with high mortality. HLA-DR, CD64, and PD-1 were assumed to be useful biomarkers for sepsis prediction. However, the ability of a combination of these biomarkers has not been clarified. METHODS: An observational case-control study was conducted that included 30 sepsis patients, 30 critically ill patients without sepsis admitted to the intensive care unit (ICU), and 32 healthy individuals. The levels of HLA-DR, CD64, and PD-1 expression in peripheral blood immune cells and subsets was assayed on Days 1, 3, and 5, and the clinical information of patients was collected. We compared these biomarkers between groups and evaluated the predictive validity of single and combined biomarkers on sepsis mortality. RESULTS: The results indicate that PD-1 expression on CD4- CD8- T (PD-1+ CD4- CD8- T) (19.19% ± 10.78% vs. 9.88% ± 1.79%, p = .004) cells and neutrophil CD64 index (nCD64 index) (9.15 ± 5.46 vs. 5.33 ± 2.34, p = .001) of sepsis patients were significantly increased, and HLA-DR expression on monocytes (mHLA-DR+ ) was significantly reduced (13.26% ± 8.06% vs. 30.17% ± 21.42%, p = 2.54 × 10-4 ) compared with nonsepsis critically ill patients on the first day. Importantly, the expression of PD-1+ CD4- CD8- T (OR = 0.622, 95% CI = 0.423-0.916, p = .016) and mHLA-DR+ (OR = 1.146, 95% CI = 1.014-1.295, p = .029) were significantly associated with sepsis mortality. For sepsis diagnosis, the mHLA-DR+ , PD-1+ CD4- CD8- T, and nCD64 index showed the moderate individual performance, and combinations of the three biomarkers achieved greater diagnostic value (AUC = 0.899, 95% CI = 0.792-0.962). When adding PCT into the combined model, the AUC increased to 0.936 (95% CI = 0.840-0.983). For sepsis mortality, combinations of PD-1+ CD4- CD8- T and mHLA-DR+ , have a good ability to predict the prognosis of sepsis patients, with an AUC = 0.921 (95% CI = 0.762-0.987). CONCLUSION: These findings indicate that the combinations of HLA-DR, CD64, and PD-1 outperformed each of the single indicator in diagnosis and predicting prognosis of sepsis.

Non-enzymatic heparanase enhances gastric tumor proliferation via TFEB-dependent autophagy.

Heparanase (HPA) is the predominant enzyme that cleaves heparan sulfate and plays a critical role in a variety of pathophysiological processes. HPA activity has been traditionally correlated with tumor metastasis due to participation in the cleavage and remodeling of the extracellular matrix (ECM). Apart from its well-characterized catalytic properties, HPA was noticed to exert biological functions not rely on its enzymatic activity. This feature is supported by studies showing induction of signaling events, such as Src and AKT, by nonenzymatic HPA mutant. We provide evidence here that active HPA and inactive HPA mutant proteins enhance gastric cancer cell growth, possibly attributed to TFEB-mediated autophagy. Similarly, HPA gene silencing resulted in decreased gastric cancer cell proliferation and autophagy. Besides, TFEB inhibition reduced cell growth and autophagy induced by nonenzymatic HPA. Notably, HPA and TFEB were significantly elevated in gastric carcinomas compared with the adjacent gastric tissue. Moreover, the elevation of HPA gene expression and upregulation of TFEB levels have been associated with advanced clinical stage and poor prognosis of gastric cancer, providing strong clinical support for a connection between TFEB and HPA. Thus, neutralizing the nonenzymatic function of HPA and the related TFEB-driven autophagy may profoundly impact gastric cancer progression.

Glycyrrhizin alleviates sepsis-induced acute respiratory distress syndrome via suppressing of HMGB1/TLR9 pathways and neutrophils extracellular traps formation.

BACKGROUND: Neutrophil extracellular traps (NETs) are involved in the development of sepsis-induced acute respiratory distress syndrome (ARDS). Glycyrrhizin (GL), the main active ingredient of the traditional Chinese medicine Glycyrrhiza glabra, has anti-inflammatory, anti-viral, and immunomodulatory effects. OBJECTIVE: The study aims to explore the efficacy and potential mechanism of GL on sepsis-induced ARDS in mice. MATERIALS AND METHODS: Mice were randomly divided into 3 groups: Control, CLP, and GL + CLP. Mice sepsis ARDS model was induced by cecal ligation and puncture (CLP) followed by intraperitoneal GL treatment. Then, the 7-day survival rate of mice was recorded. The lung function of mice was determined by whole-body plethysmography. Lung pathology and scores were observed by hematoxylin-eosin staining. The wet/dry ratio (W/D) of the lung was measured by weighing method. The protein concentration in bronchoalveolar lavage fluid (BALF) was measured by the BCA method. NETs formation in lung tissue was detected by immunofluorescence. Furthermore, HMGB1、TLR9、MyD88 and IL6 expression in lung tissue were detected by western blot and by quantitative real-time PCR, respectively. RESULTS: The results showed that GL improved the survival rate, attenuated lung tissue injury and reduced the expression of inflammatory factors in mice with CLP-induced sepsis. Meanwhile, we confirmed that GL could inhibit TLR9 / MyD88 activation from reducing NETs formation by decreasing HMGB1 expression. The formation of NETs is regulated by HMGB1 / TLR9 / MyD88. In addition, GL improved lung function in mice with sepsis-induced ARDS. Lung function suggested that GL increased alveolar ventilation, alleviated ventilator fatigue and reduced airway resistance in mice with ARDS induced by sepsis. CONCLUSIONS: GL ameliorated sepsis-induced ARDS and reduced the NETs formation in lung tissues, which may be associated with the inhibition of the HMGB1 / TLR9 pathway.

[Value of peripheral blood monocyte subsets and CD64 expression in the diagnosis and prognosis of sepsis].

OBJECTIVE: To explore the value of monocyte subsets and CD64 expression in the diagnosis and prognosis of sepsis. METHODS: A prospective case-control study was designed. 30 septic patients and 30 non-septic patients who were admitted to the intensive care unit (ICU) of the PLA Army Characteristic Medical Center from March 2021 to March 2022 were enrolled. After 1, 3, and 5 days of ICU admission, peripheral blood samples were taken from patients. Flow cytometry was used to detect the proportion of monocyte subsets and the expression level of CD64 on the surface, and the difference of expression between patients in two group was analyzed. The risk variables for sepsis were analyzed using single-factor and multi-factor Logistic regression. The diagnostic efficacy of each risk factor for sepsis was determined using the receiver operator characteristic curve (ROC curve). RESULTS: One day after ICU admission, the proportions of monocytes and classic monocytes in white blood cells (WBC) of septic patients were significantly lower than those of non-septic patients [proportion of monocytes to WBC: (4.13±2.03)% vs. (6.53±3.90)%, proportion of classic monocytes to WBC: 1.97 (1.43, 2.83)% vs. 3.37 (1.71, 5.98)%, both P < 0.05]. The proportion of non-classical monocytes in monocytes was significantly higher in septic patients than that in non-septic patients [(11.42±9.19)% vs. (6.57±4.23)%, P < 0.05]. The levels of CD64 expression in monocytes, classic monocytes, intermediate monocytes and non-classic monocytes were significantly higher in sepsis patients than those in non-septic patients [mean fluorescence intensity (MFI): 13.10±6.01 vs. 9.84±2.83 for monocytes, 13.58±5.98 vs. 10.03±2.84 for classic monocytes, 13.48±6.35 vs. 10.22±2.99 for intermediate monocytes, 8.21±5.52 vs. 5.79±2.67 for non-classic monocytes, all P < 0.05]. Multivariate Logistic regression research showed that CD64 in typical monocytes [odds ratio (OR) = 1.299, 95% confidence interval (95%CI) was 1.027-1.471, P = 0.025] and the proportion of non-typical monocytes in monocytes (OR = 1.348, 95%CI was 1.034-1.758, P = 0.027) were the independent risk factors for sepsis. ROC curve showed that the area under the ROC curve (AUC) of CD64 expression of classical monocytes, the fraction of non-classical monocytes in monocytes, and procalcitonin (PCT) in the diagnosis of sepsis was 0.871. A correlation analysis revealed a negative relationship between the acute physiology and chronic health status evaluation II (APACHE II) on the first, third, and fifth days following ICU admission and the expression level of CD64 in patients' classic monocytes (r values were -0.264, -0.428 and -0.368, respectively, all P < 0.05). CONCLUSIONS: Combining the proportion of non-classical monocytes in monocytes, the level of plasma PCT, and the CD64 expression of classic monocytes in peripheral blood has good efficacy in identifying sepsis and assessing its severity.

Exogenous growth hormone functionally alleviates glucocorticoid-induced longitudinal bone growth retardation in male rats by activating the Ihh/PTHrP signaling pathway.

Glucocorticoid (GC)-induced longitudinal bone growth retardation is a common and severe adverse effect in pediatric patients receiving GC immunosuppressive therapy. Molecular mechanisms underlying GC-induced growth inhibition are unclear. GC withdrawal following short-term high-dose use is common, including in the immediate post-transplant period. However, whether skeleton growth recovery is sufficient or whether growth-promoting therapy is required following GC withdrawal is unknown. The aim of this study was to investigate the effect of exogenous growth hormone (GH) on growth plate impairment in GC-induced longitudinal bone growth retardation. Here, apoptotic chondrocytes in the hypertrophic layer of growth plates increased whereas Indian Hedgehog (Ihh) and Parathyroid Hormone Related Peptide (PTHrP) protein levels in the growth plate decreased following GC exposure. The hypertrophic zone of the growth plate expanded following GC withdrawal. Subcutaneously injected GH penetrated the growth plate and modified its organization in rats following GC withdrawal. Ihh and PTHrP expression in GC-induced apoptotic chondrocytes decreased in vitro. GH promoted chondrocyte proliferation by activating Ihh/PTHrP signaling. Downregulating Ihh using specific siRNAs increased chondrocyte apoptosis and inhibited PTHrP, Sox9, and type II collagen (Col2a1) protein expression. GH inhibited apoptosis of Ihh-deficient growth plate chondrocytes by upregulating PTHrP, Sox9, and Col2a1 expression. Thus, reversal of the effect of GC on growth plate impairment following its withdrawal is insufficient, and exogenous GH provides growth plate chondral protection and improved longitudinal growth following GC withdrawal by acting on the Ihh/PTHrP pathway.

PDGFR kinase inhibitor protects against septic death via regulation of BTLA.

Sepsis, defined as life-threatening organ failure caused by a dysregulated host response to severe infection, is a major cause of death among intensive care unit patients. Therapies targeting on immunomodulatory is a new research field in sepsis treatment. B- and T-lymphocyte attenuator (BTLA) is an inhibitory costimulatory factor molecule of B and T lymphocytes. Studies have shown that elevated expression of BTLA in lymphocytes can reduce mortality in sepsis, but its regulatory compounds and the underlying mechanism remains to be elucidated. Here, we show that treatment with CP-673451 significantly decreases mortality of septic mouse. CP-673451 is a PDGFR kinase inhibitor which can promote the expression of BTLA, inhibit the release of chemokines such as CXCL13, and reduce first the chemotaxis of B cells to the peripheral blood and vital organs. CP-673451 also inhibits both the release of cytokines and chemokines such as IL-1ß, IL-6, IL-10, TNF-α, CCL1, CCL2 and CCL7 and reduces both the chemotactic ability of T cells. This suggests that CP-673451 may prevent septic death by inhibiting lymphocyte chemotaxis and alleviating "cytokine storm". In conclusion, our study provides a new therapeutic target and an effective compound for sepsis treatment.

Plasma Vanin-1 as a Novel Biomarker of Sepsis for Trauma Patients: A Prospective Multicenter Cohort Study.

INTRODUCTION: Vanin-1 plays a pivotal role in oxidative stress and the inflammatory response. However, its relationship with traumatic sepsis remains unknown. The aim of our study was to evaluate whether plasma vanin-1 could be used for the early prediction of traumatic sepsis. METHODS: In this three-stage prospective cohort study, severe trauma patients admitted from January 2015 to October 2018 at two hospitals were enrolled. Plasma vanin-1 levels were measured by enzyme-linked immunosorbent assay (ELISA). The associations among variables and traumatic sepsis were identified by logistic regression models and the receiver operating characteristic (ROC) curve was analyzed to evaluate the diagnostic efficiency. RESULTS: A total of 426 trauma patients (22 in the discovery cohort, 283 in the internal test cohort, and 121 in the external validation cohort) and 16 healthy volunteers were recruited. The plasma vanin-1 of trauma patients was significantly higher than that of healthy volunteers (P < 0.05). Patients with sepsis had higher plasma vanin-1 than patients without sepsis in the discovery trauma cohort (P < 0.05). In the internal test cohort, plasma vanin-1 at day 1 after trauma was significantly associated with the incidence of sepsis (OR = 3.92, 95% CI 2.68-5.72, P = 1.62 × 10-12). As a predictive biomarker, vanin-1 afforded a better area under the curve (AUC) (0.82, 95% CI 0.77-0.87) than C-reaction protein (CRP) (0.62, 95% CI 0.56-0.68, P < 0.0001), procalcitonin (PCT) (0.66, 95% CI 0.60-0.71, P < 0.0001), and Acute Physiology and Chronic Health Evaluation II (APACHE II) (0.71, 95% CI 0.65-0.76, P = 6.70 × 10-3). The relevance was further validated in the external validation cohort (OR = 4.26, 95% CI 2.22-8.17, P = 1.28 × 10-5), with an AUC of 0.83 (95% CI 0.75-0.89). Vanin-1 could also improve the diagnostic efficiency of APACHE II (AUC = 0.85). CONCLUSIONS: Our study demonstrated that plasma vanin-1 increased among trauma patients and was independently associated with the risk of sepsis. Vanin-1 might be a potential biomarker for the early prediction of traumatic sepsis. TRIAL REGISTRATION: Clinicaltrials.gov Identifier, NCT01713205.

A Functional Variant of CXCL16 Is Associated With Predisposition to Sepsis and MODS in Trauma Patients: Genetic Association Studies.

PURPOSE: CXC chemokines are mediators which mediate immune cells migration to sites of inflammation and injury. Chemokine C-X-C motif ligand 16 (CXCL16) plays an important role in the occurrence and development of sepsis through leukocyte chemotaxis, leukocyte adhesion and endotoxin clearance. In this study, we selected a set of tagging single nucleotide polymorphisms (tag SNPs) in the CXCL16 gene and investigated their clinical relevance to the development of sepsis and multiple organ dysfunction syndrome (MODS) in patients with major trauma in three independent Chinese Han populations. METHODS: A total of 1,620 major trauma patients were enrolled in this study. Among these patients, 920 came from Chongqing in western China, 350 came from Zhejiang Province in eastern China, and 350 came from Guizhou Province in southwestern China. The improved multiplex ligation detection reaction (iMLDR) method was employed in the genotyping and genetic association analyses to determine the associations between CXCL16 haplotypes and sepsis morbidity rate and higher MOD scores in three cohorts. RESULTS: Only CXCL16 T123V181 haplotype was associated with an increased risk for sepsis morbidity and higher MOD scores in the three cohorts (OR = 1.89, P = 0.001 for the Chongqing cohort; OR = 1.76, P = 0.004 for the Zhejiang cohort; OR = 1.55, P = 0.012 for the Guizhou cohort). The effect of T123V181 haplotype on the chemotaxis, migration and endotoxin clearance of immune cells were further observed. Protein modeling analysis showed that T123 and V181 might alter the structure of the CXCL16 active center. Thus it enhanced the chemotaxis and adhesion ability of immunocytes. CONCLUSION: We demonstrate the mechanism of CXCL16 T123V181 haplotype which regulates the sepsis morbidity rate and thus provide a new biomarker for early diagnosis of sepsis and MODS. CLINICAL TRIAL REGISTRATION: www.ClinicalTrials.gov, identifier NCT01713205 (https://www.clinicaltrials.gov/ct2/results?cond=&term=+NCT01713205&cntry=&state=&city=&dist=).

[Dynamic changes of cellular immune function in trauma patients and its relationship with prognosis].

OBJECTIVE: To study the dynamic changes of cellular immune function in peripheral blood of trauma patients and its role in the evaluation of traumatic complications. METHODS: A prospective cohort study design was conducted. Patients with blunt trauma admitted to Chongqing Emergency Medical Center from November 2019 to January 2020 were consecutively enrolled. The peripheral blood samples were collected at 1, 3, 5, 7, and 14 days after injury. The expressions of CD64, CD274, and CD279 on the surface of neutrophils, lymphocytes, and monocytes as well as CD3+, CD4+ and CD8+ T lymphocyte subsets were measured by flow cytometry. The trauma patients were divided into different groups according to the injury severity score (ISS) and sepsis within 28 days after injury, respectively. The dynamic changes of cellular immune function in different time points after injury and differences between different groups were compared. Furthermore, the correlation with acute physiology and chronic health evaluation II (APACHE II), sequential organ failure assessment (SOFA), and ISS were evaluated by Pearson correlation analysis. RESULTS: A total of 42 patients with trauma were finally enrolled, containing 8 severe trauma patients with ISS greater than 25 scores, 17 patients with ISS between 16 and 25 scores, and 17 patients with ISS less than 16 scores. The sepsis morbidity rates were 14.3% (n = 6) within 28 days after injury. CD64 index and CD4+ T lymphocyte subsets were significantly increased at different time points after trauma (H = 15.464, P = 0.004; F = 2.491, P = 0.035). The CD64 index and positive rates of CD279 in neutrophils, lymphocytes, and monocytes were increased with the severity of injury at day 1 and day 3 after injury, respectively. At the first day after injury, CD64 index were 2.81±1.79, 1.77±0.92, 3.49±1.09; positive rate of CD279 in neutrophils were 1.40% (0.32%, 2.04%), 0.95% (0.44%, 2.70%), 12.73% (3.00%, 25.20%); positive rate of CD279 in lymphocytes were 3.77% (3.04%, 5.15%), 4.71% (4.08%, 6.32%), 8.01% (4.59%, 11.59%); positive rate of CD279 in monocytes were 0.57% (0.24%, 1.09%), 0.85% (0.22%, 1.25%), 6.74% (2.61%, 18.94%) from mild to severe injury groups, respectively. The CD64 index in severe injury group was significantly higher than that in moderate group, and the positive rates of CD279 in neutrophils, lymphocytes and monocytes of severe injury patients were higher than those in other two groups (all P < 0.05). At 3rd day after injury, compared to moderate group, severe injury patients had significantly higher CD64 index and positive rate of CD279 in lymphocytes [4.58±2.41 vs. 2.43±1.68, 7.35% (5.90%, 12.28%) vs. 4.63% (3.26%, 6.06%), both P < 0.05]. Compared with the non-sepsis patients, the sepsis patients had significantly higher CD64 index and positive rate of CD279 in monocytes at day 1 after injury [4.06±1.72 vs. 2.36±1.31, 3.29% (1.14%, 12.84%) vs. 0.67% (0.25%, 1.48%), both P < 0.05], and positive rate of CD279 in lymphocytes significantly higher at 3rd day after injury [8.73% (7.52%, 15.82%) vs. 4.67% (3.82%, 6.21%), P < 0.05]. In addition, correlation analysis showed that positive rate of CD279 in lymphocytes was positively correlated with SOFA and ISS, respectively (r values were 0.533 and 0.394, both P < 0.05), positive rate of CD279 in monocytes was positively correlated with APACHE II, SOFA and ISS scores, respectively (r values were 0.579, 0.452 and 0.490, all P < 0.01), positive rate of CD279 in neutrophils was positively correlated with APACHE II and ISS, respectively (r values were 0.358 and 0.388, both P < 0.05). CONCLUSIONS: CD64 index and CD279 expression in neutrophils, lymphocytes, and monocytes are significantly related to the severity and prognosis of trauma. Dynamic monitoring the cellular immune function may be helpful for assessing the prognosis of trauma patients.

Polygenic Risk Score for Early Prediction of Sepsis Risk in the Polytrauma Screening Cohort.

BACKGROUND: Increasing genetic variants associated with sepsis have been identified by candidate-gene and genome-wide association studies, but single variants conferred minimal alterations in risk prediction. Our aim is to evaluate whether a weighted genetic risk score (wGRS) that aggregates information from multiple variants could improve risk discrimination of traumatic sepsis. METHODS: Sixty-four genetic variants potential relating to sepsis were genotyped in Chinese trauma cohort. Genetic variants with mean decrease accuracy (MDA) > 1.0 by random forest algorithms were selected to construct the multilocus wGRS. The area under the curve (AUC) and net reclassification improvement (NRI) were adopted to evaluate the discriminatory and reclassification ability of weighted genetic risk score (wGRS). RESULTS: Seventeen variants were extracted to construct the wGRS in 883 trauma patients. The wGRS was significantly associated with sepsis after trauma (OR = 2.19, 95% CI = 1.53-3.15, P = 2.01 × 10-5) after being adjusted by age, sex, and ISS. Patients with higher wGRS have an increasing incidence of traumatic sepsis (P trend = 6.81 × 10-8), higher SOFA (P trend = 5.00 × 10-3), and APACHE II score (P trend = 1.00 × 10-3). The AUC of the risk prediction model incorporating wGRS into the clinical variables was 0.768 (95% CI = 0.739-0.796), with an increase of 3.40% (P = 8.00 × 10-4) vs. clinical factor-only model. Furthermore, the NRI increased 25.18% (95% CI = 17.84-32.51%) (P = 6.00 × 10-5). CONCLUSION: Our finding indicated that genetic variants could enhance the predictive power of the risk model for sepsis and highlighted the application among trauma patients, suggesting that the sepsis risk assessment model will be a promising screening and prediction tool for the high-risk population.

Optimal H2O2 preconditioning to improve bone marrow mesenchymal stem cells' engraftment in wound healing.

BACKGROUND: The transplantation of bone marrow mesenchymal stem cells (BMSCs) is a promising therapeutic strategy for wound healing. However, the poor migration capacity and low survival rate of transplanted BMSCs in wounds weaken their potential application. OBJECTIVE: To identify the optimal protocol for BMSCs preconditioned with H2O2 and improve the therapeutic efficacy using H2O2-preconditioned BMSCs in wound healing. METHODS: Mouse BMSCs were exposed to various concentrations of H2O2, and the key cellular functional properties were assessed to determine the optimal precondition with H2O2. The H2O2-preconditioned BMSCs were transplanted into mice with full-thickness excisional wounds to evaluate their healing capacity and tissue engraftment. RESULTS: Treatment BMSCs with 50 µM H2O2 for 12 h could significantly enhance their proliferation, migration, and survival by maximizing the upregulation of cyclin D1, SDF-1, and its receptors CXCR4/7 expressions, and activating the PI3K/Akt/mTOR pathway, but inhibiting the expression of p16 and GSK-3ß. Meanwhile, oxidative stress-induced BMSC apoptosis was also significantly attenuated by the same protocol pretreatment with a decreased ratio of Bax/Bcl-2 and cleaved caspase-9/3 expression. Moreover, after the identification of the optimal protocol of H2O2 precondition in vitro, the migration and tissue engraftment of transfused BMSCs with H2O2 preconditioning were dramatically increased into the wound site as compared to the un-preconditioned BMSCs. The increased microvessel density and the speedy closure of the wounds were observed after the transfusion of H2O2-preconditioned BMSCs. CONCLUSIONS: The findings suggested that 50 µM H2O2 pretreated for 12 h is the optimal precondition for the transplantation of BMSCs, which gives a considerable insight that this protocol may be served as a promising candidate for improving the therapeutic potential of BMSCs for wound healing.