LncRNA 220, a newly discovered long non-conding RNA inhibiting apoptosis and autophagy in Kupffer cells in LPS-induced endotoxemic mice through the XBP1u-PI3K-AKT pathway.

Sepsis is recognized as a potentially fatal condition characterized by acute organ dysfunction resulting from an imbalanced immune response to infection. Acute liver injury (ALI) arises as an inflammatory outcome of immune response dysregulation associated with sepsis. Kupffer cells, which are liver-specific macrophages, are known to have a significant impact on ALI, although the precise regulatory mechanism remains unclear. Numerous studies have showcased the regulatory impact of long non-coding RNAs (lncRNAs) on the progression of diverse ailments, yet their precise regulatory mechanisms remain predominantly unexplored. In this study, a novel long non-coding RNA (lncRNA), referred to as lncRNA 220, was discovered using high-throughput sequencing. The expression of lncRNA 220 was found to be significantly elevated in the livers of mice with lipopolysaccharide (LPS)-induced endotoxemia, specifically during the 8-hour time period. Furthermore, in Kupffer cells treated with LPS, lncRNA 220 was observed to inhibit apoptosis and autophagy by activating the PI3K-AKT-mTORC1 pathway. This effect was achieved through the reduction of X-box protein 1 unspliced (Xbp1u) mRNA stability and suppression of its translation in the context of endoplasmic reticulum stress (ERS). Ultimately, this intervention mitigated the progression of LPS-induced ALI. To summarize, our study establishes lncRNA 220 as a newly identified regulator that suppresses apoptosis and autophagy in Kupffer cells subjected to LPS treatment, indicating its potential as a molecular target for ALI in endotoxemic mice.

Integrated Analyses of Single-Cell Transcriptome and Mendelian Randomization Reveal the Protective Role of Resistin in Sepsis Survival in Intensive Care Unit.

The high morbidity and mortality rates associated with sepsis highlight the challenges of finding specific remedies for this condition in the intensive care unit (ICU). This study aimed to explore the differentially expressed genes (DEGs) specific to cell types in sepsis and investigate the role of resistin in the survival of sepsis patients through Mendelian randomization (MR) analyses. We used single-cell and bulk transcriptome data to identify cell type-specific DEGs between sepsis and healthy controls. MR analyses were then conducted to investigate the causal relationships between resistin (one of the identified DEGs) levels and the survival of sepsis patients. Additionally, we utilized meQTL (methylation quantitative trait loci) to identify cytosine-phosphate-guanine (CpG) sites that may directly affect sepsis. We identified 560 cell type-specific DEGs between sepsis and healthy controls. Notably, we observed the upregulation of resistin levels in macrophages during sepsis. In bulk transcriptome, RETN is also upregulated in sepsis samples compared with healthy controls. MR analyses revealed a negative association existed between the expression of resistin, at both gene and protein levels, and the mortality or severity of sepsis patients in ICU. Moreover, there were no associations observed between resistin levels and death or organ failure due to other causes. We also identified three methylation CpG sites, located in RETN or its promoter region-cg06633066, cg22322184, and cg02346997-that directly affected both resistin protein levels and sepsis death in the ICU. Our findings suggest that resistin may provide feasible protection for sepsis patients, particularly those with severe cases, without serious side effects. Therefore, resistin could be a potential drug candidate for sepsis treatment. Additionally, we identified two CpG sites, cg06633066 and cg22322184, that were associated with RETN protein levels and sepsis death, providing novel insights into the underlying mechanisms of sepsis.

LILAR, a novel long noncoding RNA regulating autophagy in the liver tissues of endotoxemic mice through a competing endogenous RNA mechanism.

Sepsis is an often-deadly complication of infection that can lead to multiple organ failure. Previous studies have demonstrated that autophagy has a protective effect on liver injury in sepsis. Here, we report a novel long noncoding RNA (lncRNA), named lipopolysaccharide (LPS)-induced liver autophagy regulator (LILAR), which was highly induced in the liver tissues of endotoxemic mice. LILAR deficiency significantly increased the susceptibility of mice to LPS. In contrast, LILAR overexpression rescued the liver injury mediated by LILAR deficiency and increased the survival of LILAR knockout mice with endotoxemia. Autophagy-related protein 13 (Atg13) is a potential downstream target gene of LILAR. LILAR deficiency notably decreased Atg13 expression and suppressed autophagy in the livers of mice challenged with LPS. A reporter gene assay showed that LILAR competitively adsorbed miR-705 to increase the expression of Atg13 in cultured cells, indicating that LILAR participates in the regulation of the autophagy in the liver tissues of endotoxemic mice through a competitive endogenous RNA mechanism. In summary, we identified a novel lncRNA, LILAR, as a hepatic autophagy regulator, which not only promotes our understanding of liver pathophysiology but also provides a potential therapeutic target and/or diagnostic biomarker for liver injury in endotoxemia.

Keratin7 and Desmoplakin are involved in acute lung injury induced by sepsis through RAGE.

Keratin 7 (Krt7) is a member of the keratin family and is primarily involved in cytoskeleton composition. It has been shown that Krt7 is able to influence its own remodeling and interactions with other signaling molecules via phosphorylation at specific sites unique to Krt7. However, its molecular mechanism in acute lung injury (ALI) remains unclear. In this study, differential proteomics was used to analyze lung samples from the receptor for advanced glycation end products (RAGE)-deficient and (wild-type)WT-septic mice. We screened for the target protein Krt7 and identified Ser53 as the phosphorylation site using mass spectrometry (MS), and this phosphorylation further triggered the deformation and disintegration of Desmoplakin (Dsp), ultimately leading to epithelial barrier dysfunction. Furthermore, we demonstrated that in sepsis, mDia1/Cdc42/p38 MAPK signaling activation plays a role in septic lung injury. We also explored the mechanism of alveolar dysfunction of the Krt7-Dsp complex in the epithelial cell barrier. In summary, the present findings increase our understanding of the pathogenesis of septic acute lung injury.

Sustained induction of IP-10 by MRP8/14 via the IFNß-IRF7 axis in macrophages exaggerates lung injury in endotoxemic mice.

Background: As a damage-associated molecular pattern, the myeloid-related protein 8/14 (MRP8/14) heterodimer mediates various inflammatory diseases, such as sepsis. However, how MRP8/14 promotes lung injury by regulating the inflammatory response during endotoxemia remains largely unknown. This study aims at illuminating the pathological functions of MRP8/14 in endotoxemia. Methods: An endotoxemic model was prepared with wild-type and myeloid cell-specific Mrp8 deletion (Mrp8ΔMC) mice for evaluating plasma cytokine levels. Lung injury was evaluated by hematoxylin and eosin (H&E) staining, injury scoring and wet-to-dry weight (W/D) ratio. The dynamic profile of interferon γ (IFNγ)-inducible protein 10 (IP-10) mRNA expression induced by macrophage MRP8/14 was determined by quantitative real-time polymerase chain reaction (qPCR). Immunoblotting was used to evaluate the increase in IP-10 level induced by activation of the JAK-STAT signaling pathway. Luciferase reporter assay was performed to detect the involvement of IRF7 in Ip-10 gene transcription. In vivo air pouch experiments were performed to determine the biological function of IP-10 induced by MRP8/14. Results: Experiments with Mrp8ΔMC mice showed that MRP8/14 promoted the production of cytokines, including IP-10, in the bronchoalveolar lavage fluid (BALF) and lung injury in endotoxic mice. The result of qPCR showed sustained expression of Ip-10 mRNA in macrophages after treatment with MRP8/14 for 12 h. Neutralization experiments showed that the MRP8/14-induced Ip-10 expression in RAW264.7 cells was mediated by extracellular IFNß. Western blotting with phosphorylation-specific antibodies showed that the JAK1/TYK2-STAT1 signaling pathway was activated in MRP8/14-treated RAW264.7 cells, leading to the upregulation of Ip-10 gene expression. IRF7 was further identified as a downstream regulator of the JAK-STAT pathway that mediated Ip-10 gene expression in macrophages treated with MRP8/14. In vivo air pouch experiments confirmed that the IFNß-JAK1/TYK2-STAT1-IRF7 pathway was required for chemokine (C-X-C motif) receptor 3 (CXCR3)+ T lymphocyte migration, which promoted lung injury in the context of endotoxemia. Conclusions: In summary, our study demonstrates that MRP8/14 induces sustained production of IP-10 via the IFNß-JAK1/TYK2-STAT1-IRF7 pathway to attract CXCR3+ T lymphocytes into lung tissues and ultimately results in lung injury by an excessive inflammatory response in the context of endotoxemia.

LncRNA 220: A Novel Long Non-Coding RNA Regulates Autophagy and Apoptosis in Kupffer Cells via the miR-5101/PI3K/AKT/mTOR Axis in LPS-Induced Endotoxemic Liver Injury in Mice.

Sepsis is a severe medical condition distinguished by immune systematic dysfunction and multiple organic injury, or even failure, resulting from an acute systemic inflammatory response. Acute liver injury (ALI) could be considered as a notable inflammatory outcome of sepsis. Studies have demonstrated the essential roles played by long non-coding RNAs (lncRNAs) in mediating the processes of various diseases, including their ability to engage in interactions with microRNAs (miRNAs) as complexes of competing endogenous RNA (ceRNA) to modulate signaling pathways. In this study, a newly discovered lncRNA, named 220, was identified to function in regulating autophagy and apoptosis in Kupffer cells treated with lipopolysaccharide (LPS). This was achieved through sponging miR-5101 as a ceRNA complex, as identified via high-throughput sequencing. The expression of 220 was found to be significantly different in the hepatic tissues of endotoxemic mice that were treated with LPS for 8 h, ultimately modulating the ALI process. Our studies have collectively demonstrated that 220 is a novel regulator that acts on LPS-induced autophagy and apoptosis in Kupffer cells, thereby mediating the ALI process induced by LPS. Furthermore, the validation of our findings using clinical databases suggests that 220 could potentially serve as a molecular target of clinical, diagnostic, and therapeutic significance in septic liver injury.

Interfacial assembly of chitin/Mn3O4 composite hydrogels as photothermal antibacterial platform for infected wound healing.

To combat bacteria and even biofilm infections, developing alternative antibacterial wound dressings independent of antibiotics is imperative. Herein, this study developed a series of bioactive chitin/Mn3O4 composite hydrogels under mild conditions for infected wound healing application. The in situ synthesized Mn3O4 NPs homogeneously distribute throughout chitin networks and strongly interact with chitin matrix, and as well as endow the chitin/Mn3O4 hydrogels with NIR-assisted outstanding photothermal antibacterial and antibiofilm activities. Meantime, the chitin/Mn3O4 hydrogels exhibit favorable biocompatibility and antioxidant property. Furthermore, the chitin/Mn3O4 hydrogels with the assist of NIR show an excellent skin wound healing performance in a mouse full-thickness S. aureus biofilms-infected wound model, by accelerating the phase transition from inflammation to remodeling. This study broadens the scope for the fabrication of chitin hydrogels with antibacterial property, and offers an excellent alternative for the bacterial-associated wound infection therapy.

Pregnancy-induced changes to the gut microbiota drive macrophage pyroptosis and exacerbate septic inflammation.

The physiological and immune changes that occur during pregnancy are associated with worsened disease outcomes during infection and sepsis. How these perturbations exacerbate inflammation has not been explored. Here, using antibiotic treatment and fecal microbial transfers, we showed that sepsis susceptibility is driven by pregnancy-induced changes to gut microbiome in mice and humans. Integrative multiomics and genetically engineered bacteria revealed that reduced Parabacteroides merdae (P. merdae) abundance during pregnancy led to decreased formononetin (FMN) and increased macrophage death. Mechanistically, FMN inhibited macrophage pyroptosis by suppressing nuclear accumulation of hnRNPUL2 and subsequent binding to the Nlrp3 promoter. Treatment with FMN or deletion of murine hnRNPUL2 protected against septic inflammation. Intestinal abundances of P. merdae and FMN inversely correlated with the progression of septic patients. Our data reveal a microbe-immune axis that is disrupted in pregnant septic hosts, highlighting the potential of the FMN-hnRNPUL2-NLRP3 axis in providing promising therapeutic strategies for sepsis.

Gut microbial metabolite hyodeoxycholic acid targets the TLR4/MD2 complex to attenuate inflammation and protect against sepsis.

Sepsis, a critical condition resulting from the systemic inflammatory response to a severe microbial infection, represents a global public health challenge. However, effective treatment or intervention to prevent and combat sepsis is still lacking. Here, we report that hyodeoxycholic acid (HDCA) has excellent anti-inflammatory properties in sepsis. We discovered that the plasma concentration of HDCA was remarkably lower in patients with sepsis and negatively correlated with the severity of the disease. Similar changes in HDCA levels in plasma and cecal content samples were observed in a mouse model of sepsis, and these changes were associated with a reduced abundance of HDCA-producing strains. Interestingly, HDCA administration significantly decreased systemic inflammatory responses, prevented organ injury, and prolonged the survival of septic mice. We demonstrated that HDCA suppressed excessive activation of inflammatory macrophages by competitively blocking lipopolysaccharide binding to the Toll-like receptor 4 (TLR4) and myeloid differentiation factor 2 receptor complex, a unique mechanism that characterizes HDCA as an endogenous inhibitor of inflammatory signaling. Additionally, we verified these findings in TLR4 knockout mice. Our study highlights the potential value of HDCA as a therapeutic molecule for sepsis.

NONO regulates multiple cytokine production in sepsis via the ERK1/2 signaling pathway.

The massive release of pro-inflammatory cytokines is a crucial step in triggering the inflammatory cascade in sepsis. Exploring the key molecules regulating the expression and release of multiple cytokines has important value for revealing the mechanism of the cytokine storm in sepsis. This study aimed to investigate the role of multifunctional nuclear protein non-POU domain containing octamer-binding protein (NONO) in the sepsis cytokine storm and to elucidate the underlying mechanism. We found that NONO expression in tissues and cells of sepsis mice was significantly upregulated. Downregulation of NONO expression inhibited the mRNA expression of multiple cytokines, including IL-6, IL-1ß, MCP-1, MIP-1α, and MIP-1ß in inflammatory cells from mice and human leukemic monocyte-THP1 cells challenged with lipopolysaccharide (LPS), and significantly decreased the level of these cytokines and TNF-α in the supernatant of THP1 cells challenged by LPS. Nono knockout also reduced the levels of TNF-α, IL-6, MIP-1α, and MIP-1ß in serum, alleviated hepatocyte edema, and improved the survival rate of sepsis mice. Reduced NONO expression decreased the phospho-ERK1/2 level in inflammatory cells from sepsis mice or THP1 cells challenged by LPS. Phospho-ERK1/2 inhibitor decreased the mRNA expression and concentration of cytokines in the culture supernatant of LPS-induced THP1 cells, similar to the effect of NONO knockdown. After LPS challenge, the levels of phospho-ERK1/2 and NONO were increased, with obvious colocalization in the nucleus and vesicular-like organelles in macrophages. NONO knockdown decreased nuclear translocation of phospho-ERK1/2 in LPS-challenged THP1 cells. These results suggest that NONO is a potentially critical molecule involved in multiple cytokine production in sepsis. Upregulated NONO in sepsis may promote the expression and release of multiple cytokines to participate in a sepsis cytokine storm by promoting ERK1/2 phosphorylation.

Mepiquat chloride application combined with high plant population density promotes carbon remobilization in the roots of upland cotton.

Carbon reserves in cotton roots can be remobilized to support reproductive growth, thus potentially affecting cotton yield. However, the regulation of carbon remobilization in cotton roots and its relationship with cotton yield are still poorly understood. Plant population density (PPD) and mepiquat chloride (MC) have been hypothesized to affect the dynamics of nonstructural carbohydrate content and the resulting carbon remobilization in cotton roots through the regulation of carbohydrate metabolism enzyme activities. A mid-maturation cotton line 4003-6 was field-grown in 2019 and 2020. Three different levels of PPD (D1: 2.25 plants m-2, D2: 4.5 plants m-2, and D3: 6.75 plants m-2) and two levels of MC dosage (M0: 0 g hm-2, M1: 82.5 g hm-2) were combined to create six populations differing in terms of the source-sink relationship. The changes in the hexose, sucrose, and starch contents and the key carbon metabolic enzyme activities in cotton roots were examined during peak squaring (PS) to late boll opening (LB). The combination of the PPD of 6.75 plants m-2 and MC application (M1D3) exhibited the greatest cotton yield and reproductive biomass-to-leaf area ratio from peak flowering (PF) onwards. M1D3 presented the greatest total nonstructural carbohydrate (TNC) remobilization amount of 2.96 and 3.80 g m-2, the highest efficiency of 39.11% and 48.39%, and the largest gross contribution to seed cotton yield of 0.66% and 0.79% in 2019 and 2020, respectively. The three parameters were positively correlated with the seed cotton yield except for the remobilization rate in 2019. Unlike the other treatments, the greater carbohydrate content per unit ground area in M1D3 prior to the PF stage was attributed to the higher sucrose phosphate synthase (SPS) and ADP-glucose pyrophosphorylase (AGPase) activities during the PS to first flowering (FF) stages. Conversely, the greater α-amylase and ß-amylase activities in M1D3 at the PF stage accounted for the lower starch content at the EB stage, and the smaller vacuolar invertase (VIN) and cell wall invertase (CWIN) activities at the EB stage could be responsible for the lower hexose concentration at that time. The TNC remobilization amount had a positive association with the AGPase and SPS activities at the FF stage and with ß-amylase activity at the PF stage in cotton tap roots in 2019 and 2020. This study provides a cotton yield-improving alternative through the promotion of carbon remobilization in roots using certain agronomic practices.

Methylation-Mediated Silencing of RBP7 Promotes Breast Cancer Progression through PPAR and PI3K/AKT Pathway.

Retinoid-binding protein7 (RBP7) is a member of the cellular retinol-binding protein (CRBP) family, which is involved in the pathogenesis of breast cancer. The study aims to illustrate the prognostic value and the potential regulatory mechanisms of RBP7 expression in breast cancer. Bioinformatics analysis with the TCGA and CPTAC databases revealed that the mRNA and protein expression levels of RBP7 in normal were higher compared to breast cancer tissues. Survival analysis displayed that the lower expression of RBP7, the worse the prognosis in ER-positive (ER+) breast cancer patients. Genomic analysis showed that low expression of RBP7 correlates with its promoter hypermethylation in breast cancer. Functional enrichment analysis demonstrated that downregulation of RBP7 expression may exert its biological influence on breast cancer through the PPAR pathway and the PI3K/AKT pathway. In summary, we identified RBP7 as a novel biomarker that is helpful for the prognosis of ER+ breast cancer patients. Promoter methylation of RBP7 is involved in its gene silencing in breast cancer, thus regulating the occurrence and development of ER+ breast cancer through the PPAR and PI3K/AKT pathways.

Identification of differentially expressed genes at the single-cell level and prognosis prediction through bulk RNA sequencing data in breast cancer.

Background: The invention and development of single-cell technologies have contributed a lot to the understanding of tumor heterogeneity. The objective of this research was to investigate the differentially expressed genes (DEGs) between normal and tumor cells at the single-cell level and explore the clinical application of these genes with bulk RNA-sequencing data in breast cancer. Methods: We collected single-cell, bulk RNA sequencing (RNA-seq) and microarray data from two public databases. Through single-cell analysis of 23,909 mammary gland cells from seven healthy donors and 33,138 tumor cells from seven breast cancer patients, cell type-specific DEGs between normal and tumor cells were identified. With these genes and the bulk RNA-seq data, we developed a prognostic signature and validated the efficacy in two independent cohorts. We also explored the differences of immune infiltration and tumor mutational burden (TMB) between the different risk groups. Results: A total of 6,175 cell-type-specific DEGs were obtained through the single-cell analysis between normal and tumor cells in breast cancer, of which 1,768 genes intersected with the bulk RNA-seq data. An 18-gene signature was constructed to assess the outcomes in breast cancer patients. The efficacy of the signature was notably prominent in two independent cohorts. The low-risk group showed higher immune infiltration and lower TMB. Among the 18 genes in the signature, 16 were also differentially expressed in the bulk RNA-seq dataset. Conclusion: Cell-type-specific DEGs between normal and tumor cells were identified through single-cell transcriptome data. The signature constructed with these DEGs could stratify patients efficiently. The signature was also closely correlated with immune infiltration and TMB. Nearly all the genes in the signature were also differentially expressed at the bulk RNA-seq level.

1,25(OH)2D3 promotes the elimination of Klebsiella pneumoniae infection by inducing autophagy through the VDR-ATG16L1 pathway.

OBJECTIVE: Previous studies have shown that vitamin D has regulatory functions in both innate and adaptive immune responses, indicating that it can perform essential roles in host resistance to pathogen infections. This study aimed to verify its effects on Klebsiella pneumoniae (Kp) infection and explore the underlying mechanisms. METHODS: THP-1-derived macrophages were infected with Kp and then incubated with 1,25(OH)2D3. Autophagy induced by 1,25(OH)2D3 was investigated by western blotting and immunofluorescence. Real-time PCR (qPCR) was performed to determine the expression of inflammatory mediators. Baf A1 and 3-MA were used to inhibit autophagy. The intracellular killing of Kp was measured using qPCR and colony-forming unit assays. RNA interference assays were used to silence VDR or ATG16L1. The lungs of C57BL/6 mice were infected with Kp via intratracheal instillation, and the established pneumonia models were used for in vivo validation experiments. RESULTS: Treatment with 1,25(OH)2D3 enhanced the bactericidal activity of macrophages and concomitantly reduced the expression of the pro-inflammatory mediators TNF-α and IL-6. Kp infection led to a lower expression level of VDR in macrophages than in the control, whereas co-treatment with 1,25(OH)2D3 up-regulated VDR expression and robustly induced autophagy via the VDR signaling pathway. Silencing ATG16L1 significantly counteracted autophagy induced by 1,25(OH)2D3 in Kp-infected macrophages. Furthermore, we found that when autophagy activity was diminished by ATG16L1 siRNA or blocked by Baf A1, the ability of 1,25(OH)2D3 to promote macrophages to eliminate Kp infection was obviously impaired, as were its anti-inflammatory effects. These protective efficacies of 1,25(OH)2D3 against Kp infection were also validated in vivo using a mouse model of pneumonia. CONCLUSIONS: The present study demonstrated the protective features of 1,25(OH)2D3 in macrophages against Kp infection and may provide evidence for further exploration of its potential as an adjunctive therapy agent for the treatment of bacterial infections.

XBP1 impacts lung adenocarcinoma progression by promoting plasma cell adaptation to the tumor microenvironment.

Background: The activation of X-box binding protein 1 (XBP1) plays an essential role in the unfolded protein response (UPR) of the endoplasmic reticulum (ER). XBP1 is commonly expressed in various tumors and is closely related to tumorigenesis and progression. However, the role of XBP1 in lung adenocarcinoma (LUAD), especially the prognostic value of its alternative splicing isoforms, remains largely unknown. Methods: The LUAD datasets were retrieved from the The Cancer Genome Atlas, ArrayExpress and Gene Expression Omnibus. GEPIA2 and meta-analysis were employed to explore the prognostic value, and bioinformatics analysis with the TIMER2.0 database was used to investigate immune cell infiltration. We performed single-cell analyses to identify cell types with high XBP1 expression. In addition, polymerase chain reaction (PCR) and DNA sequencing were performed to verify the authenticity of the new spliceosome. Results: In this study, we found that high expression of XBP1 was significantly associated with a good prognosis, and XBP1 expression was significantly positively correlated with B cell infiltration in LUAD. In addition, we found that high-level expression of a novel splicing isoform, XBP1 (XBP1-003), improved the prognosis of LUAD. Protein structural analysis demonstrated that XBP1-003 has several specific protein domains that are different from those of other XBP1 isoforms, indicating a unique function of this isoform in LUAD. Conclusion: All these results suggest that XBP1 plays an antitumorigenic role in LUAD through alternative splicing, which may be related to the adaptation of plasma cells. This sheds new light on the potential strategy for LUAD prognosis evaluation and immunotherapy.

Identification of heptapeptides targeting a lethal bacterial strain in septic mice through an integrative approach.

Effectively killing pathogenic bacteria is key for the treatment of sepsis. Although various anti-infective drugs have been used for the treatment of sepsis, the therapeutic effect is largely limited by the lack of a specific bacterium-targeting delivery system. This study aimed to develop antibacterial peptides that specifically target pathogenic bacteria for the treatment of sepsis. The lethal bacterial strain Escherichia coli MSI001 was isolated from mice of a cecal ligation and puncture (CLP) model and was used as a target to screen bacterial binding heptapeptides through an integrative bioinformatics approach based on phage display technology and high-throughput sequencing (HTS). Heptapeptides binding to E. coli MSI001 with high affinity were acquired after normalization by the heptapeptide frequency of the library. A representative heptapeptide VTKLGSL (VTK) was selected for fusion with the antibacterial peptide LL-37 to construct the specific-targeting antibacterial peptide VTK-LL37. We found that, in comparison with LL37, VTK-LL37 showed prominent bacteriostatic activity and an inhibitive effect on biofilm formation in vitro. In vivo experiments demonstrated that VTK-LL37 significantly inhibited bacterial growth, reduced HMGB1 expression, alleviated lesions of vital organs and improved the survival of mice subjected to CLP modeling. Furthermore, membrane DEGP and DEGQ were identified as VTK-binding proteins by proteomic methods. This study provides a novel strategy for targeted pathogen killing, which is helpful for the treatment of sepsis in the era of precise medicine.

The multiomics landscape of serum exosomes during the development of sepsis.

INTRODUCTION: Sepsis is an infection-induced severe inflammatory disorder leading to multiple organ dysfunction. It remains a highly lethal condition for which early diagnosis and therapy achieve unsatisfactory results. Circulating exosomes containing biomarkers and mediators of sepsis have recently received attention, but the progress has been far from optimal. OBJECTIVES: The present study focuses on the profiles of molecular dynamics in serum exosomes and explores the potential molecular mechanisms on serum exosomes during the process of sepsis. METHODS: We used high-performance liquid chromatography-tandem mass spectrometry and RNA-seq to detect the dynamic profiles of exosome proteins and RNAs (including mRNAs, lncRNAs and miRNAs) in serum exosomes from 3 healthy individuals and 9 septic patients at the different stages. Then integrative multiomics analyses were performed and the results were validated by qRT-PCR, LiquiChip assay and metabolomics analysis on mice subjected to cecal ligation and puncture (CLP) modeling. RESULTS: A total of 354 proteins, 195 mRNAs, 82 lncRNAs and 55 miRNAs were identified as differentially expressed molecules in serum exosomes from septic patients. Integrative multiomics analysis showed that exosome components were associated with cytokine storm, complement and clotting cascades, the endothelial barrier, 20S proteasome-dependent protein degradation and vitamin metabolism. Importantly, pretreatment with serum exosomes derived from mice subjected to CLP significantly restrained proinflammatory cytokine expression and alleviated tissue injury in septic mice. Further metabolomics analysis demonstrated that pretreatment with septic serum exosomes significantly affected the metabolites associated with vitamin digestion and absorption in CLP mice. CONCLUSION: Our study for the first time describes the landscape of the molecular dynamics of serum exosomes during the development of sepsis and proposes some hypothetical molecular mechanisms by integrative multiomics analysis, which may provide helpful diagnostic and therapeutic insights for the ongoing battle against sepsis.

Identification of a pyroptosis-related prognostic signature in breast cancer.

BACKGROUND: The relationship between pyroptosis and cancer is complex. It is controversial that whether pyroptosis represses or promotes tumor development. This study aimed to explore prognostic molecular characteristics to predict the prognosis of breast cancer (BRCA) based on a comprehensive analysis of pyroptosis-related gene expression data. METHODS: RNA-sequcing data of BRCA were collected from The Cancer Genome Atlas (TCGA) and Gene Expression Ominibus (GEO) datasets. First, pyroptosis-related differentially expressed genes (DEGs) between normal and tumor tissues were identified from the TCGA database. Based on the DEGs, 1053 BRCA patients were divided into two clusters. Second, DEGs between the two clusters were used to construct a signature by a least absolute shrinkage and selection operator (LASSO) Cox regression model, and the GEO cohort was used to validate the signature. Various statistical methods were applied to assess this gene signature. Finally, Single-sample gene set enrichment analysis (ssGSEA) was employed to compare the enrichment scores of 16 types of immune cells and 13 immune-related pathways between the low- and high-risk groups. We calculated the tumor mutational burden (TMB) of TCGA cohort and evaluated the correlations between the TMB and riskscores of the TCGA cohort. We also compared the TMB between the low- and high-risk groups. RESULTS: A total of 39 pyroptosis-related DEGs were identified from the TCGA-breast cancer dataset. A prognostic signature comprising 16 genes in the two clusters of DEGs was developed to divide patients into high-risk and low-risk groups, and its prognostic performance was excellent in two independent patient cohorts. The high-risk group generally had lower levels of immune cell infiltration and lower activity of immune pathway activity than did the low-risk group, and different risk groups revealed different proportions of immune subtypes. The TMB is higher in high-risk group compared with low-risk group. OS of low-TMB group is better than that of high-TMB group. CONCLUSION: A 16-gene signature comprising pyroptosis-related genes was constructed to assess the prognosis of breast cancer patients and its prognostic performance was excellent in two independent patient cohorts. The signature was found closely associated with the tumor immune microenvironment and the potential correlation could provide some clues for further studies. The signature was also correlated with TMB and the mechanisms are still warranted.

Antioxidant Fusion Protein SOD1-Tat Increases the Engraftment Efficiency of Total Bone Marrow Cells in Irradiated Mice.

Total body irradiation is a standard procedure of bone marrow transplantation (BMT) which causes a rapid increase in reactive oxygen species (ROS) in the bone marrow microenvironment during BMT. The increase in ROS reduces the engraftment ability of donor cells, thereby affecting the bone marrow recovery of recipients after BMT. In the early weeks following transplantation, recipients are at high risk of severe infection due to weakened hematopoiesis. Thus, it is imperative to improve engraftment capacity and accelerate bone marrow recovery in BMT recipients. In this study, we constructed recombinant copper/zinc superoxide dismutase 1 (SOD1) fused with the cell-penetrating peptide (CPP), the trans-activator of transcription (Tat), and showed that this fusion protein has penetrating ability and antioxidant activity in both RAW264.7 cells and bone marrow cells in vitro. Furthermore, irradiated mice transplanted with SOD1-Tat-treated total bone marrow donor cells showed an increase in total bone marrow engraftment capacity two weeks after transplantation. This study explored an innovative method for enhancing engraftment efficiency and highlights the potential of CPP-SOD1 in ROS manipulation during BMT.