Organellophagy regulates cell death:A potential therapeutic target for inflammatory diseases.

BACKGROUND: Dysregulated alterations in organelle structure and function have a significant connection with cell death, as well as the occurrence and development of inflammatory diseases. Maintaining cell viability and inhibiting the release of inflammatory cytokines are essential measures to treat inflammatory diseases. Recently, many studies have showed that autophagy selectively targets dysfunctional organelles, thereby sustaining the functional stability of organelles, alleviating the release of multiple cytokines, and maintaining organismal homeostasis. Organellophagy dysfunction is critically engaged in different kinds of cell death and inflammatory diseases. AIM OF REVIEW: We summarized the current knowledge of organellophagy (e.g., mitophagy, reticulophagy, golgiphagy, lysophagy, pexophagy, nucleophagy, and ribophagy) and the underlying mechanisms by which organellophagy regulates cell death. KEY SCIENTIFIC CONCEPTS OF REVIEW: We outlined the potential role of organellophagy in the modulation of cell fate during the inflammatory response to develop an intervention strategy for the organelle quality control in inflammatory diseases.

Targeting the mechanism of IRF3 in sepsis-associated acute kidney injury via the Hippo pathway.

Sepsis-induced inflammatory damage and adaptive repair are critical in the pathophysiological mechanisms of acute kidney injury (AKI). Here, we investigated the role of interferon regulatory factor three (IRF3) and subsequent activation of the Hippo pathway in inflammatory damage and repair using an in vitro cell model of LPS-induced AKI. LPS caused the phosphorylation and activation of IRF3 in the early stages of sepsis, and activated IRF3 enhanced the production of type I interferon (IFN), resulting in an excessive inflammatory response. Furthermore, LPS generated considerably more inflammatory injury than intended cell death, and IRF3 activation triggered the Hippo pathway, causing a reduction in YAP, which eventually impaired proliferation and repair in surviving renal tubular epithelial cells and exacerbated the development of AKI. In conclusion, IRF3 promoted the development of sepsis-associated AKI (SAKI) by modulating the Hippo pathway.

Corrigendum: Bioinformatics and system biology approach to identify the influences among COVID-19, ARDS and sepsis.

[This corrects the article DOI: 10.3389/fimmu.2023.1152186.].

Bioinformatics and system biology approach to identify the influences among COVID-19, ARDS and sepsis.

Background Severe coronavirus disease 2019 (COVID -19) has led to severe pneumonia or acute respiratory distress syndrome (ARDS) worldwide. we have noted that many critically ill patients with COVID-19 present with typical sepsis-related clinical manifestations, including multiple organ dysfunction syndrome, coagulopathy, and septic shock. The molecular mechanisms that underlie COVID-19, ARDS and sepsis are not well understood. The objectives of this study were to analyze potential molecular mechanisms and identify potential drugs for the treatment of COVID-19, ARDS and sepsis using bioinformatics and a systems biology approach. Methods Three RNA-seq datasets (GSE171110, GSE76293 and GSE137342) from Gene Expression Omnibus (GEO) were employed to detect mutual differentially expressed genes (DEGs) for the patients with the COVID-19, ARDS and sepsis for functional enrichment, pathway analysis, and candidate drugs analysis. Results We obtained 110 common DEGs among COVID-19, ARDS and sepsis. ARG1, FCGR1A, MPO, and TLR5 are the most influential hub genes. The infection and immune-related pathways and functions are the main pathways and molecular functions of these three diseases. FOXC1, YY1, GATA2, FOXL, STAT1 and STAT3 are important TFs for COVID-19. mir-335-5p, miR-335-5p and hsa-mir-26a-5p were associated with COVID-19. Finally, the hub genes retrieved from the DSigDB database indicate multiple drug molecules and drug-targets interaction. Conclusion We performed a functional analysis under ontology terms and pathway analysis and found some common associations among COVID-19, ARDS and sepsis. Transcription factors-genes interaction, protein-drug interactions, and DEGs-miRNAs coregulatory network with common DEGs were also identified on the datasets. We believe that the candidate drugs obtained in this study may contribute to the effective treatment of COVID-19.

Fallopian tubal infertility: the result of Chlamydia trachomatis-induced fallopian tubal fibrosis.

Chlamydia trachomatis is one of the most common pathogens of sexually transmitted diseases, and its incidence in genital tract infections is now 4.7% in south China. Infertility is the end result of C. trachomatis-induced fallopian tubal fibrosis and is receiving intense attention from scientists worldwide. To reduce the incidence of infertility, it is important to understand the pathology-related changes of the genital tract where C. trachomatis infection is significant, especially the mechanism of fibrosis formation. During fibrosis development, the fallopian tube becomes sticky and occluded, which will eventually lead to tubal infertility. At present, the mechanism of fallopian tubal fibrosis induced by C. trachomatis infection is unclear. Our study attempted to summarize the possible mechanisms of fibrosis caused by C. trachomatis infection in the fallopian tube by reviewing published studies and further providing potential therapeutic targets to reduce the occurrence of infertility. This study also provides ideas for future research. Factors leading to fallopian tube fibrosis include inflammatory factors, miRNA, ECT, cHSP, and host factors. We hypothesized that C. trachomatis mediates the transcription and translation of EMT and ECM via upregulating TGF signaling pathway, which leads to the formation of fallopian tube fibrosis and ultimately to tubal infertility.

Frequency of and risk factors for intensive care unit-acquired sacrum pressure injuries in critically ill patients: A multicenter cross-sectional study in China.

RATIONALE AIMS AND OBJECTIVES: Hospital-acquired pressure injuries (HAPI) prolong hospital stays and are an important health problem worldwide. The aim of this study was to assess the frequency of and risk factors for intensive care unit (ICU)-acquired pressure injuries (IAPI) on the sacrum in critically ill patients in China. METHODS: We performed a multicenter, cross-sectional survey of IAPI on the sacrum in 23 adult ICUs in 19 hospitals in China. Data for 421 critically ill patients were collected on December 13, 2019, and January 13, 2020, including patient characteristics, physiological, and clinical information. Logistic regression was used to analyze the risk factors for IAPI on the sacrum in the ICU. RESULTS: Forty-one patients presented sacrum pressure injuries in the ICU, with a frequency of 9.74%. Risk factors that significantly increased the risk of IAPI on the sacrum were lower body mass index (BMI, odds ratio [OR] = 1.115, confidence interval [CI]: 1.011-1.229, P = .029), chronic obstructive pulmonary disease (COPD, OR = 3.183, CI: 1.261-8.037, P = .014), multiple organ dysfunction syndrome (MODS, OR = 2.670, CI: 1.031-6.903, P = .043), and a lower Braden risk score (OR = 1.409, CI: 1.197-1.659, P < .001). CONCLUSION: Lower BMI, COPD, MODS, and lower Braden risk score are independent risk factors for sacrum IAPI in China.

[Design and application of a multifunctional infrared wind heating medical rewarming equipment].

Hypothermia can have adverse effects on various systems of trauma patients, and significantly increase the mortality. All of the current rewarming equipments are contact rewarming equipment, which have the shortcomings of single function and poor effect. The medical staff of the First People's Hospital of Chenzhou designed a multi-functional infrared heating medical rewarming equipment, and obtained the National Utility Model Patent of China (ZL 2018 2 1705172.9). By integrating the infrared heating lamp tube and the air heating device and controlling them independently, the equipment can not only treat the wound by infrared alone, but also keep the wound warm by using the air heating function at low room temperature. In addition, it can also warm the patients with hypothermia separately. The device's dual functions of promoting wound healing and rewarming by infrared therapy and wind-heating are accurate. It is easy to operate with good controllability, and contributes to individualized precision treatment, which is worthy of transformation and promotion.

LncRNA GAS5 inhibits miR-579-3p to activate SIRT1/PGC-1α/Nrf2 signaling pathway to reduce cell pyroptosis in sepsis-associated renal injury.

Sepsis is a life-threatening condition that can lead to several organ failures including kidney. In this study, we investigated the roles of GAS5 and miR-579-3p in regulating cell pyroptosis in the sepsis-induced renal injury model. Lipopolysaccharide (LPS) treatment or cecal ligation and puncture (CLP) surgery was used to create the in vitro and in vivo sepsis-induced renal injury model. The interactions between GAS5 and miR-579-3p, and miR-579-3p and SIRT1 were determined by bioinformatic prediction, luciferase reporter assay, and RIP assay. In vitro cell pyroptosis was examined by flow cytometry marked with active caspase-1 and PI. The protein levels of IL-1ß and IL-18 induced by cell pyroptosis were quantified using ELISA assay. In vivo renal injuries were evaluated with HE and TUNEL stainings, bacterial load in serum and creatinine, and blood urea nitrogen content analyses. Expression levels of GAS5, miR-579-3p, pyroptosis, and SIRT1/PGC-1a/Nrf2 pathway-related molecules were evaluated by qRT-PCR or Western blot. GAS5 and SIRT1 were downregulated, whereas miR-579-3p was upregulated in in vitro and in vivo sepsis-induced renal injury models. GAS5 negatively and directly regulated miR-579-3p to reduce cell pyroptosis via the activation of SIRT1/PGC-1a/Nrf2 pathway. In addition, miR-579-3p suppressed PGC-1a/Nrf2 pathway to induce cell pyroptosis by directly targeting SIRT1. What's more, overexpression of GAS5, or knockdown of miR-579-3p, enhanced SIRT1 expression that led to the improved survival rate, reduced the weight loss, and relieved renal injuries in septic mice. Overexpression of GAS5 demonstrated protective effects against sepsis-induced renal injury via downregulating miR-579-3p and activating SIRT1/PGC-1α/Nrf2 pathway to inhibit cell pyroptosis.

Prevalence and genotype distribution of HPV infection among 214,715 women from Southern China, 2012-2018: baseline measures prior to mass HPV vaccination.

BACKGROUND: The epidemiology on the human papillomavirus (HPV) among females in Southern China is not well-established. Baseline data on the prevalence of HPV infection in China prior to mass prophylactic HPV vaccination would be useful. Thus, this study aims to determine the type-specific HPV prevalence and distribution among females from Southern China prior to mass HPV vaccination. METHODS: A retrospective cross-sectional study employing 214,715 women attending ChenZhou NO.1 People's Hospital for cervical screening during 2012-2018 was conducted prior to widespread HPV vaccination. HPV genotype was detected using nucleic acid molecular diversion hybridization tests. The overall prevalence, age-specific prevalence, type distribution, and annual trend were analyzed. RESULTS: The overall HPV prevalence was 18.71% (95% confidence interval [CI], 18.55-18.88%) among Southern China females. During 2012-2018, the prevalence of HPV infection showed a downward tendency, from 21.63% (95% CI, 21.07-22.20%) in 2012 to 18.75% (95% CI, 18.35-19.16%) in 2018. Age-specific HPV distribution displayed a peak at young women aged less than 21 years (33.11, 95% CI, 31.13-35.15%), 20.07% (95% CI, 19.70-20.44%) among women aged 21-30 years, 17.29% (95% CI, 17.01-17.57%) among women aged 31-40 years, 17.23% (95% CI, 16.95-17.51%) among women aged 41-50 years, 21.65% (95% CI, 21.11-22.20%) among women aged 51-60 years, and 25.95% (95% CI, 24.86-27.07%) among women aged over 60 years. Of the 21 subtypes identified, the top three prevalent high-risk HPV (HR-HPV) genotypes were HPV52 (5.12%; 95% CI, 21.11-22.20%), - 16 (2.96%; 95% CI, 2.89-3.03%), and - 58 (2.51%; 95% CI, 2.44-2.58%); the predominant low-risk HPV (LR-HPV) genotypes were HPV81 (1.86%; 95%CI, 1.80-1.92%) and - 6 (0.69%; 95% CI, 0.66-0.73%) respectively. Incidence of HR-HPV only, LR-HPV only and mixed LR- and HR-HPV were 15.17, 2.07 and 1.47% respectively. Besides, single HPV infection accounted for 77.30% of all positive cases in this study. CONCLUSIONS: This study highlights 1) a high prevalence of HPV infection among females with a decreasing tendency towards 2012-2018, especially for young women under the age of 21 prior to mass HPV vaccination; 2) HPV52, - 16 and - 58 were the predominant HPV genotypes, suggesting potential use of HPV vaccine covering these HPV genotypes in Southern China.

The interaction between C/EBPß and TFAM promotes acute kidney injury via regulating NLRP3 inflammasome-mediated pyroptosis.

Sepsis-induced inflammatory damage is a crucial cause of acute kidney injury (AKI), and AKI is an ecumenical fearful complication in approximately half of patients with sepsis. CCAAT/enhancer-binding protein ß (C/EBPß) plays roles in regulating acute phase responses and inflammation. However, the role and mechanism of C/EBPß in AKI are unclear. LPS combined with ATP-treated renal epithelial cells HK2 and cecal ligation-peferation (CLP)-mice were used as models of AKI in vitro and in vivo. Cell damage, the secretion of interleukin-1 beta (IL-1ß), IL-18 and cysteinyl aspartate specific proteinase 1 (caspase-1) activity were tested by LDH, ELISA assay and flow cytometry analysis, respectively. The expression levels of TFAM, C/EBPß, and pyroptosis-related molecules were tested by qRT-PCR and Western blotting. Chromatin immunoprecipitation (ChIP) assessed the interaction between C/EBPß with TFAM. Hematoxylin-Eosin (H&E) staining detected pathological changes of kidney tissues, and immunohistochemistry measured TFAM and C/EBPß in mice kidney tissues. C/EBPß or TFAM were up-regulated in LPS combined with ATP -induced HK2 cells. Knockdown of C/EBPß could suppress cell injury and the secretion of IL-1ß and IL-18 induced by LPS combined with ATP. Furthermore, C/EBPß up-regulated the expression levels of TFAM via directly binding to TFAM promoter. Overexpression of TFAM reversed the effects of C/EBPß deficiency on pyroptosis. Knockdown of C/EBPß could inhibit NLRP3 inflammasome-mediated caspase-1 signaling pathway by inactivating TFAM/RAGE pathway. It was further confirmed in the AKI mice that C/EBPß and TFAM promoted AKI by activating NLRP3-mediated pyroptosis. The interaction of between C/EBPß and TFAM facilitated pyroptosis by activating NLRP3/caspase-1 signal axis, thereby promoting the occurrence of AKI.

Role of Parkin-mediated mitophagy in the protective effect of polydatin in sepsis-induced acute kidney injury.

BACKGROUND: We have reported that polydatin (PD) alleviates mitochondrial dysfunction in rat models of sepsis-induced acute kidney injury (SI-AKI), but the mechanism is not well understood. Here, we investigated the role of Parkin-mediated mitophagy in the protective effects of PD in SI-AKI in mice. METHODS: Sepsis was induced in the mice by caecal ligation and puncture. Mitophagy was determined by mitochondrial mass. NLRP3 inflammasome activation was determined by NLRP3, ASC and caspase-1. Mitophagy was blocked by treatment with mitochondrial division inhibitor-1 and Parkin knockout. KEY RESULTS: PD treatment increased the sepsis-induced loss of mitochondrial mass, indicating the upregulation of mitophagy. Furthermore, PD treatment mediated Parkin translocation from the cytoplasm to the mitochondria. This suggests that Parkin-mediated mitophagy is an underlying mechanism. This was confirmed by the suppression of PD-induced mitophagy in Parkin-/- mice and in mice that were treated with a mitophagy inhibitor. PD-induced Parkin translocation and mitophagy were blocked by inhibiting SIRT1; thus, activation of SIRT1 might be an important molecular mechanism that is triggered by PD. Additionally, PD treatment protected against sepsis-induced kidney injury. These effects were blocked by inhibition of Parkin-dependent mitophagy. Furthermore, PD also protected against mitochondrial dysfunction and mitochondria-dependent apoptosis, and the effect was blocked when Parkin-dependent mitophagy was inhibited. Finally, PD suppressed NLRP3 inflammasome activation that was also dependent on Parkin-mediated mitophagy. CONCLUSIONS: These findings indicate that Parkin-mediated mitophagy is important for the protective effect of PD in SI-AKI, and the underlying mechanisms include the inhibition of mitochondrial dysfunction and NLRP3 inflammasome activation.

Involvement of phosphatase and tensin homolog-induced putative kinase 1-Parkin-mediated mitophagy in septic acute kidney injury.

BACKGROUND: Studies have reported mitophagy activation in renal tubular epithelial cells (RTECs) in acute kidney injury (AKI). Phosphatase and tensin homolog-induced putative kinase 1 (PINK1) and E3 ubiquitin-protein ligase Parkin are involved in mitophagy regulation; however, little is known about the role of PINK1-Parkin mitophagy in septic AKI. Here we investigated whether the PINK1-Parkin mitophagy pathway is involved in septic AKI and its effects on cell apoptosis in vitro and on renal functions in vivo. METHODS: Mitophagy-related gene expression was determined using Western blot assay in human RTEC cell line HK-2 stimulated with bacterial lipopolysaccharide (LPS) and in RTECs from septic AKI rats induced by cecal ligation and perforation (CLP). Autophagy-related ultrastructural features in rat RTECs were observed using electron microscopy. Gain- and loss-of-function approaches were performed to investigate the role of the PINK1-Parkin pathway in HK-2 cell mitophagy. Autophagy activators and inhibitors were used to assess the effects of mitophagy modulation on cell apoptosis in vitro and on renal functions in vivo. RESULTS: LPS stimulation could significantly induce LC3-II and BECN-1 protein expression (LC3-II: 1.72 ±â€Š0.05 vs. 1.00 ±â€Š0.05, P < 0.05; BECN-1: 5.33 ±â€Š0.57 vs. 1.00 ±â€Š0.14, P < 0.05) at 4 h in vitro. Similarly, LC3-II, and BECN-1 protein levels were significantly increased and peaked at 2 h after CLP (LC3-II: 3.33 ±â€Š0.12 vs. 1.03 ±â€Š0.15, P < 0.05; BECN-1: 1.57 ±â€Š0.26 vs. 1.02 ±â€Š0.11, P < 0.05) in vivo compared with those after sham operation. Mitochondrial deformation and mitolysosome-mediated mitochondria clearance were observed in RTECs from septic rats. PINK1 knockdown significantly attenuated LC3-II protein expression (1.35 ±â€Š0.21 vs. 2.38 ±â€Š0.22, P < 0.05), whereas PINK1 overexpression markedly enhanced LC3-II protein expression (2.07 ±â€Š0.21 vs. 1.29 ±â€Š0.19, P < 0.05) compared with LPS-stimulated HK-2 cells. LPS-induced proapoptotic protein expression remained unchanged in autophagy activator-treated HK-2 cells and was significantly attenuated in PINK1-overexpressing cells, but was remarkably upregulated in autophagy inhibitor-treated and in PINK1-depleted cells. Consistent results were observed in flow cytometric apoptosis assay and in renal function indicators in rats. CONCLUSION: PINK1-Parkin-mediated mitophagy might play a protective role in septic AKI, serving as a potential therapeutic target for septic AKI.

Upregulation of Mitochondrial Transcription Factor A Promotes the Repairment of Renal Tubular Epithelial Cells in Sepsis by Inhibiting Reactive Oxygen Species-Mediated Toll-Like Receptor 4/p38MAPK Signaling.

BACKGROUND: Mitochondrial transcription factor A (TFAM) plays multiple pathophysiologic roles in mitochondrial DNA (mtDNA) maintenance. However, the role of TFAM in sepsis-induced acute kidney injury (AKI) remains largely unknown. METHODS: Lipopolysaccharide (LPS) treatment of HK-2 cells mimics the in vitro model of AKI inflammation. pcDNA3.1 plasmid was used to construct pcDNA3.1-TFAM. sh-TFAM-543, sh-TFAM-717, sh-TFAM-765, sh-TFAM-904 and pcDNA3.1-TFAM were transfected into HK-2 cells using Lipofectamine 2000. MtDNA transcriptional levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR). 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay was performed to assess the cell viability. Changes in reactive oxygen species (ROS) and mitochondrial membrane potential in HK-2 cells were detected using the corresponding kits. Immunofluorescence experiment was used to investigate the displacement of TFAM. mRNA and protein expression levels of TFAM and its related genes were measured by qRT-PCR and western blot respectively. Mice in sepsis were administered cecal ligation and puncture surgery. RESULTS: LPS treatment was a non-lethal influencing factor, leading to the upregulation of ROS levels and downregulation of mtDNA copy number and NADH dehydrogenase subunit-1 (ND1) expression, and caused damage to the mitochondria. As the LPS treatment time increased, TFAM was displaced from the periphery of the nucleus to cytoplasm. TFAM reduced ROS and P38MAPK levels by inhibiting toll-like receptor 4 (TLR4) expression, ultimately inhibiting inflammation and repairing mtDNA. CONCLUSIONS: Our results indicate that TFAM repairs mtDNA by blocking the TLR4/ROS/P38MAPK signaling pathway in inflammatory cells, thereby repairing septic tubular epithelial cells, and TFAM may serve as a new target for sepsis therapy.

Evidence for SIRT1 Mediated HMGB1 Release From Kidney Cells in the Early Stages of Hemorrhagic Shock.

BACKGROUND: This study is to explore the effect of SIRT1 deacetylating inactivation on organ-derived high mobility group box 1 (HMGB1) during the development of severe hemorrhagic shock (HS). METHODS: Hemorrhagic shock model was reproduced in rats by blood shedding and mimicked in HK-2 cells by hypoxia-reoxygenation (H/R) treatment. The level and acetylation of HMGB1 and the expression and activity of SIRT1 were detected in tissue, serum and cultured cells and supernatant. The deacetylated sites of HMGB1 was determined by Co-IP. RESULTS: Serum HMGB1 in HS rats was increased but were reduced in multiple organs, especially in kidney tissue, with enhanced HMGB1 acetylation, and reduced deacetylase SIRT1 activity in isolated RTECs. HMGB1 in suspension of H/R-treated HK-2 cells was increased, accompanying with enhanced HMGB1 acetylation, and nuclear-plasma translocation. SIRT1 down-regulated by siRNA aggravated acetylation of HMGB1 and nucleus-to-cytoplasm translocation and resulted in increased HMGB1 in cultured HK-2 suspension. Immunoprecipitation data suggested that SIRT1-indcuced deacetylated sites of HMGB1 were K90 and K177 following H/R. SIRT1 overexpression inhibited the acetylation of HMGB1 and reduced the content of extracellular HMGB1 in H/R-treated HK-2 cells. Inhibiting mutation of SIRT1 restored the acetylation of HMGB1 and HMGB1 content in extracellular suspension. In HS rat model, the neutralization of HMGB1 with antibody could reduce serum HMGB1 and pro-inflammatory cytokine contents, but had no effect on SIRT1 protein expression and activity. Polydatin (PD), a potential SIRT1 agonist, up-regulated SIRT1 activity and inhibited nucleus-to-cytoplasm translocation of HMGB1 in RTECs. Moreover, PD also attenuated RTEC apoptosis, protected renal function, and prolonged survival in HS rats. These beneficial effect of PD is largely blocked by specific inhibition of SIRT1 with Ex527. CONCLUSION: The acetylation of HMGB1 in K99 and K177 is enhanced during HS due to the downregulation of SIRT1. The nucleus-to-cytoplasm translocation and the release of acetylated HMGB1 from RTECs of kidney might exacerbate the pro-inflammatory effects of HMGB1 during the development of HS.

Potential Role of HMGCS2 in Tumor Angiogenesis in Colorectal Cancer and Its Potential Use as a Diagnostic Marker.

Objective: HMGCS2 is the rate-limiting enzyme of ketogenesis, which is vital for tumor initiation or metastasis. The aim of this study is to determine the relationship between HMGCS2 and tumor angiogenesis. Materials and Methods: The study consisted of 100 cases with colorectal cancer and healthy control, the expression of HMGCS2 and the microvessel density (MVD) (marker: CD31) were analyzed by immunohistochemistry and tube formation, and the centration of ß-hydroxybutyrate in serum was assessed by biochemical analysis. Results: The results showed that HMGCS2 expression is significantly reduced in colorectal cancer compared with healthy control, which is inversely correlated with MVD in colorectal cancer by IHC analysis. What is more, knockdown HMGCS2 expression in HT-29 cells significantly contributed endothelial cell tube formation. Conclusion: These findings implying HMGCS2 may have a negative regulation of tumor angiogenesis and provide an approach to inhibit tumor angiogenesis.

Polydatin mediates Parkin-dependent mitophagy and protects against mitochondria-dependent apoptosis in acute respiratory distress syndrome.

Mitophagy removes dysfunctional mitochondria and is known to play an important role in the pathogenesis of several diseases; however, the role of mitophagy in acute respiratory distress syndrome (ARDS) remains poorly understood. While we have previously demonstrated that polydatin (PD) improves lipopolysaccharide (LPS)-induced ARDS, the specific mechanism remains unclear. In present study, we aimed to determine whether PD activates Parkin-dependent mitophagy to protect against LPS-induced mitochondria-dependent apoptosis and lung injury. To establish the ARDS model, C57BL/6 mice were intratracheally injected with LPS (5 mg/kg) in vivo and Beas-2B cells were exposured to 0.5 mM LPS in vitro. Our results indicate that PD facilitates Parkin translocation to mitochondria and promotes mitophagy in ARDS-challenged mice and LPS-treated Beas-2B cells. However, PD-induced mitophagy was suppressed in Parkin-/- mice and Parkin siRNA transfected cells, indicating that PD activates Parkin-dependent mitophagy. Furthermore, the protective effects of PD against LPS-induced mitochondria-dependent apoptosis and lung injury were suppressed when Parkin was depleted both in vivo and in vitro. The inhibition of mitophagy with mitophagy inhibitor mitochondrial division inhibitor-1 in vivo and silencing of autophagy-related gene 7 in vitro also blocked the protective effects mediated by PD. Our data suggest that Parkin-dependent mitophagy induced by PD provides protection against mitochondria-dependent apoptosis in ARDS.

SIRT1-mediated HMGB1 deacetylation suppresses sepsis-associated acute kidney injury.

Sepsis is the leading cause of death in the intensive care unit and continues to lack effective treatment. It is widely accepted that high-mobility group box 1 (HMGB1) is a key inflammatory mediator in the pathogenesis of sepsis. Moreover, some studies indicate that the functions of HMGB1 depend on its molecular localization and posttranslational modifications. Our previous study confirms that sirtuin 1, silent information regulator 2-related enzyme 1 (SIRT1), a type III deacetylase, can ameliorate sepsis-associated acute kidney injury (SA-AKI). We explored the effect and mechanism of SIRT1 on HMGB1 using a mouse model of cecal ligation and puncture-induced sepsis and LPS-treated human kidney (HK-2) cell line. We found that HMGB1 is elevated in the serum but is gradually reduced in kidney cells in the later stages of septic mice. The acetylation modification of HMGB1 is a key process before its nucleus-to-cytoplasm translocation and extracellular secretion in kidney cells, accelerating the development of SA-AKI. Moreover, SIRT1 can physically interact with HMGB1 at the deacetylated lysine sites K28, K29, and K30, subsequently suppressing downstream inflammatory signaling. Thus the SIRT1-HMGB1 signaling pathway is a crucial mechanism in the development of SA-AKI and presents a novel experimental perspective for future SA-AKI research.

[Predictive value of four different scoring systems for septic patient's outcome: a retrospective analysis with 311 patients].

OBJECTIVE: To study the predicting value of four different scoring systems such as the acute physiology and chronic health evaluation II (APACHE II) score, sequential organ failure assessment (SOFA) score, quick SOFA (qSOFA) score and systemic inflammatory response syndrome (SIRS) score for the prognosis of septic patients. METHODS: A retrospective analysis were conducted. Septic patients in intensive care unit (ICU) of the First People's Hospital of Chenzhou form July 1st, 2012 to June 30th, 2016 were enrolled. Patients were divided into survival group and death group according to 28-day outcome. The difference of clinic data, the worst clinical index value within 24 hours, whether mechanical ventilation performed on first day, length of stay in ICU, APACHE II score, SOFA score, qSOFA score and SIRS score were compared between the two groups. The significant different factors of sepsis outcome in univariate analysis were analyzed by multiple logistic regression, and the ability of four scoring systems was tested by receiver operating characteristic (ROC) curve. RESULTS: 311 patients were enrolled in this study (221 survivals, 90 deaths, 28-day mortality rate 28.9%). Univariate analysis showed age, mechanical ventilation ratio, urine output, length of stay in ICU and the fastest heart beat rate (HR), the lowest systolic blood pressure (SBP), the lowest mean arterial pressure (MAP), HCO3-, minimum arterial blood oxygen partial pressure (PaO2), minimum oxygenation index (PaO2/FiO2), the maximum fraction of inspired oxygen (FiO2), Na+, the highest concentration of blood urea nitrogen (BUN), the highest concentration of serum creatinine (SCr), minimum concentration of plasma albumin (Alb), Glasgow coma score (GCS) score, APACHE II score, SOFA score, qSOFA score, within 24 hours after diagnosis were significantly different between two groups (all P < 0.05). Multiple logistic regression showed age [odds ratio (OR) = 1.388, 95% confidence interval (95%CI) = 1.074-1.794, P = 0.012], PaO2/FiO2 (OR = 0.459, 95%CI = 0.259-0.812, P = 0.007), concentration of plasma Alb (OR = 0.523, 95%CI = 0.303-0.903, P = 0.020), GCS score (OR = 0.541, 95%CI = 0.303-0.967, P = 0.038) and SOFA scores (OR = 3.189, 95%CI = 1.813-5.610, P = 0.000) were independent risk factors for sepsis outcome. ROC curve test showed the APACHE II score, SOFA score and qSOFA score had the ability to predict the outcome in critical ill patients with sepsis, the SOFA score of the most powerful, the area under the ROC curve (AUC) was 0.700, when the cut-off value was 7.5 points, the sensitivity was 73.3% and specificity was 58.8%. CONCLUSIONS: APACHE II score, SOFA score and qSOFA score have the predictive properties for septic patients. SOFA score is an independent prognostic risk factor of sepsis, while qSOFA score can be widely used in clinical practice as the advantage of quick evaluating.

Dexmedetomidine attenuates lipopolysaccharide-induced acute lung injury by inhibiting oxidative stress, mitochondrial dysfunction and apoptosis in rats.

Previous studies have identified that dexmedetomidine (DEX) treatment can ameliorate the acute lung injury (ALI) induced by lipopolysaccharide and ischemia-reperfusion. However, the molecular mechanisms by which DEX ameliorates lung injury remain unclear. The present study investigated whether DEX, which has been reported to exert effects on oxidative stress, mitochondrial permeability transition pores and apoptosis in other disease types, can exert protective effects in lipopolysaccharide (LPS)­induced ALI by inhibiting oxidative stress, mitochondrial dysfunction and mitochondrial­dependent apoptosis. It was revealed that LPS­challenged rats exhibited significant lung injury, characterized by the deterioration of histopathology, vascular hyperpermeability, wet­to­dry weight ratio and oxygenation index (PaO2/FIO2), which was attenuated by DEX treatment. DEX treatment inhibited LPS­induced mitochondrial dysfunction, as evidenced by alleviating the cellular ATP and mitochondrial membrane potential in vitro. In addition, DEX treatment markedly prevented the LPS­induced mitochondrial­dependent apoptotic pathway in vitro (increases of cell apoptotic rate, cytosolic cytochrome c, and caspase 3 activity) and in vivo (increases of |terminal deoxynucleotidyl transferase dUTP nick­end labeling positive cells, cleaved caspase 3, Bax upregulation and Bcl­2 downregulation). Furthermore, DEX treatment markedly attenuated LPS­induced oxidative stress, as evidenced by downregulation of cellular reactive oxygen species in vitro and lipid peroxides in serum. Collectively, the present results demonstrated that DEX ameliorates LPS­induced ALI by reducing oxidative stress, mitochondrial dysfunction and mitochondrial-dependent apoptosis.

SIRT1/3 Activation by Resveratrol Attenuates Acute Kidney Injury in a Septic Rat Model.

Sepsis often results in damage to multiple organ systems, possibly due to severe mitochondrial dysfunction. Two members of the sirtuin family, SIRT1 and SIRT3, have been implicated in the reversal of mitochondrial damage. The aim of this study was to determine the role of SIRT1/3 in acute kidney injury (AKI) following sepsis in a septic rat model. After drug pretreatment and cecal ligation and puncture (CLP) model reproduction in the rats, we performed survival time evaluation and kidney tissue extraction and renal tubular epithelial cell (RTEC) isolation. We observed reduced SIRT1/3 activity, elevated acetylated SOD2 (ac-SOD2) levels and oxidative stress, and damaged mitochondria in RTECs following sepsis. Treatment with resveratrol (RSV), a chemical SIRT1 activator, effectively restored SIRT1/3 activity, reduced acetylated SOD2 levels, ameliorated oxidative stress and mitochondrial function of RTECs, and prolonged survival time. However, the beneficial effects of RSV were greatly abrogated by Ex527, a selective inhibitor of SIRT1. These results suggest a therapeutic role for SIRT1 in the reversal of AKI in septic rat, which may rely on SIRT3-mediated deacetylation of SOD2. SIRT1/3 activation could therefore be a promising therapeutic strategy to treat sepsis-associated AKI.