PARP1 promotes NLRP3 activation via blocking TFEB-mediated autophagy in rotenone-induced neurodegeneration.

Rotenone, a widely used pesticide, causes dopaminergic neurons loss and increase the risk of Parkinson's disease (PD). However, few studies link the role of PARP1 to neuroinflammatory response and autophagy dysfunction in rotenone-induced neurodegeneration. Here, we identified that PARP1 overactivation caused by rotenone led to autophagy dysfunction and NLRP3-mediated inflammation. Further results showed that PARP1 inhibition could reduce NLRP3-mediated inflammation, which was effectively eliminated by TFEB knockdown. Moreover, PARP1 poly(ADP-ribosyl)ated TFEB that reduced autophagy. Of note, PARP1 inhibition could rescue rotenone-induced dopaminergic neurons loss. Overall, our study revealed that PARP1 blocks autophagy through poly (ADP-ribosyl)ating TFEB and inhibited NLRP3 degradation, which suggests that intervention of PARP1-TFEB-NLRP3 signaling can be a new treatment strategy for rotenone-induced neurodegeneration.

Secreted S100A4 causes asthmatic airway epithelial barrier dysfunction induced by house dust mite extracts via activating VEGFA/VEGFR2 pathway.

The airway epithelial barrier dysfunction plays a crucial role in pathogenesis of asthma and causes the amplification of downstream inflammatory signal pathway. S100 calcium binding protein A4 (S100A4), which promotes metastasis, have recently been discovered as an effective inflammatory factor and elevated in bronchoalveolar lavage fluid in asthmatic mice. Vascular endothelial growth factor-A (VEGFA), is considered as vital regulator in vascular physiological activities. Here, we explored the probably function of S100A4 and VEGFA in asthma model dealt with house dust mite (HDM) extracts. Our results showed that secreted S100A4 caused epithelial barrier dysfunction, airway inflammation and the release of T-helper 2 cytokines through the activation of VEGFA/VEGFR2 signaling pathway, which could be partial reversed by S100A4 polyclonal antibody, niclosamide and S100A4 knockdown, representing a potential therapeutic target for airway epithelial barrier dysfunction in asthma.

Targeting circNCLN/miR-291a-3p/TSLP signaling axis alleviates lipopolysaccharide-induced acute lung injury.

Acute lung injury (ALI) is a life-threatening disease caused by the severe and acute response of the lungs to a variety of direct and indirect insults. Patients with ALI are currently treated mainly with respiratory support due to inadequate understanding of ALI progression. Alveolar epithelial cells produced thymic stromal lymphopoietin (TSLP) has been proved to worsen ALI by triggering airway inflammation. However, the regulation mechanism of TSLP expression remains unclear. In this study, we identified the crucial role played by circNCLN in lipopolysaccharide (LPS)-induced ALI. We demonstrated for the first time that miR-291a-3p could directly bind to the 3'UTR of TSLP and suppress TSLP expression in alveolar epithelial cells. Mechanistically, our data identified that circNCLN acts as a molecular sponge to antagonize miR-291a-3p and thereby maintaining the expression of TSLP in alveolar epithelial cells. Importantly, targeting circNCLN by its antisense oligonucleotide (ASO) markedly alleviated LPS-induced ALI. Therefore, our results suggested that circNCLN/miR-291a-3p/TSLP axis may be an important signaling in LPS-induced ALI and circNCLN inhibition may serve as a potential treatment of ALI.

The splicing factor SRSF1 stabilizes the mRNA of TSLP to enhance acute lung injury.

Acute lung injury (ALI) is a severe disease with a high rate of morbidity and mortality, characterized by excessive and uncontrolled inflammatory response in lung. Recent studies demonstrated that serine arginine-rich splicing factor 1 (SRSF1) is involved in inflammation. However, whether SRSF1 modulates ALI remains to be determined. In this study, we established an ALI mouse model that induced by lipopolysaccharide (LPS), with or without the treatment of SRSF1 antibody. Our result showed that SRSF1 expression was elevated in LPS-induced ALI. Importantly, treatment with SRSF1 antibody notably ameliorated ALI in mice, as determined by reduction in lung W/D ratios, histopathological changes, lung inflammation and TSLP expression. Besides, exposure of human alveolar epithelial A549 cells to LPS enhanced the expression of both SRSF1 and TSLP, while knockdown or overexpression of SRSF1 significantly lowered or upregulated the expression of TSLP induced by LPS. Interestingly, the expression of SRSF1 and TSLP showed a positive correlation in normal human lung tissues. Mechanistically, we found that SRSF1 directly bound with the mRNA of TSLP and may exert its function by stabilizing the mRNA of TSLP in LPS-induced ALI. Therefore, our results indicated that SRSF1 may be an important contributor in lung inflammation of LPS-induced ALI and SRSF1 signaling blocking may serve as a potential treatment of ALI.

The effect of continuous venovenous hemofiltration on neutrophil gelatinase-associated lipocalin plasma levels in patients with septic acute kidney injury.

BACKGROUND: It is known that continuous venonenous hemofiltration (CVVH) does not affect the plasma level of neutrophil gelatinase-associated lipocalin (pNGAL) in acute kidney injury (AKI) patients. However, because of the unique pathophysiology underlying AKI caused by sepsis, the effect of CVVH on pNGAL in this clinical setting is less certain. The purpose of this study was to determine the effect of CVVH on pNGAL in sepsis-induced AKI patients. METHODS: Between August 1, 2014, and December 31, 2014, 42 patients with sepsis-induced AKI underwent CVVH in the general intensive care unit of our institution and were consecutively enrolled in this study. Prefilter, postfilter, and ultrafiltrate pNGAL measurements were taken at the initiation of continuous renal replacement therapy (CRRT) and repeated after 2, 4, 8, and 12 h (T0, T2h, T4h, T8h, and T12h, respectively). The mass transfer, plasma clearance, and sieving coefficient were calculated based on the mass conservation principle. RESULTS: Following CVVH initiation, we found that pNGAL in the ultrafiltrate decreased significantly (P = 0.013); however, levels at the inlet and outlet showed no significant change (P > 0.05 for both). Furthermore, there was no change in the total mass removal rate, total mass adsorption rate, and plasma clearance over time (P > 0.05 for all), and a significant decrease in the sieving coefficient (P = 0.007) was seen. CONCLUSIONS: The results of this study show a limited effect of CVVH on pNGAL in sepsis-induced AKI patients. This suggests that pNGAL may be used as an indicator of renal progression in these patients. However, a larger study to confirm these findings is needed. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02536027 . Retrospectively registered on 20th August 2015.

Diagnostic value of neutrophil gelatinase-associated lipocalin, cystatin C, and soluble triggering receptor expressed on myeloid cells-1 in critically ill patients with sepsis-associated acute kidney injury.

INTRODUCTION: Neutrophil gelatinase-associated lipocalin (NGAL), cystatin C (Cys-C), and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) are novel diagnostic biomarkers of acute kidney injury (AKI). We aimed to determine the diagnostic properties of these biomarkers for detecting AKI in critically ill patients with sepsis. METHODS: We divided 112 patients with sepsis into non-AKI sepsis (n = 57) and AKI sepsis (n = 55) groups. Plasma and urine specimens were collected on admission and every 24 hours until 72 hours and tested for NGAL, Cys-C, and TREM-1 concentrations. Their levels were compared on admission, at diagnosis, and 24 hours before diagnosis. RESULTS: Both plasma and urine NGAL, Cys-C, and sTREM-1 were significantly associated with AKI development in patients with sepsis, even after adjustment for confounders by using generalized estimating equations. Compared with the non-AKI sepsis group, the sepsis AKI group exhibited markedly higher levels of these biomarkers at diagnosis and 24 hours before AKI diagnosis (P < 0.01). The diagnostic and predictive values of plasma and urine NGAL were good, and those of plasma and urine Cys-C and sTREM-1 were fair. CONCLUSION: Plasma and urine NGAL, Cys-C, and sTREM-1 can be used as diagnostic and predictive biomarkers for AKI in critically ill patients with sepsis.

Ketamine Promotes LPS-Induced Pulmonary Autophagy and Reduces Apoptosis through the AMPK/mTOR Pathway.

To explore the protective effect of ketamine on acute lung injury (ALI) in sepsis mice regarding the autophagy and apoptosis, lipopolysaccharide (LPS) was used to construct a sepsis-induced ALI model. In in vivo experiments, ketamine at a concentration of 20 mg/kg was injected before modeling. The serum levels of inflammatory factors IL-1ß, IL-6, and TNF-α were detected by enzyme-linked immunosorbent assay (ELISA) kit. At the same time, quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect apoptosis-related factors Bax and Bcl-2 and autophagy-related factors Beclin-1 and P62. In in vitro experiment, firstly, Cell Counting Kit-8 (CCK8) assay was used to detect the cell viability and identify optimal concentration of ketamine. TUNEL staining, Western blotting (WB), and qRT-PCR were used to detect alveolar type II epithelial cells (AEC II) AEC II cell apoptosis. The content of inflammatory factors in the cell supernatant was detected by kits and the autophagy intensity of AEC II cells was detected by PCR and WB. At the same time, the expression changes of AMPK/mTOR pathway were detected by WB technology. Compared with the Sham group, the dry-wet ratio of the lung tissue in the LPS group was obviously increased, the expression of inflammatory factors in the serum was upregulated, and apoptosis and autophagy activation occurred. In the LPS + ketamine group, ketamine significantly promoted autophagy intensity and inhibited inflammatory response, thereby reducing apoptosis. In vitro, 1 mmol/L ketamine can effectively improve the viability of AEC II cells after LPS treatment, promote autophagy, and decrease cell apoptosis. And we found that the above-mentioned effect of ketamine was by regulating the activation of AMPK/mTOR pathway. In this study, we demonstrated that LPS treatment can induce inflammation and autophagy and induce apoptosis in lung cells. In contrast, AMPK expression was activated after ketamine treatment, inhibiting the mTOR pathway and promoting autophagy, thereby alleviating the apoptosis of AEC II cells.

Case report: Blood purification effectively relieves multiple system failure in patient with rabies.

Rabies is an infectious disease of animal origin with a high mortality rate. In the early stages of rabies, the rabies virus (RABV) is usually undetectable in saliva and cerebrospinal fluid (CSF). In addition, there are still no effective drugs and treatments. Here, we present a case in which blood purification alleviated multisystem failures. The patient was a 45-year-old woman who presented with the fear of water and wind, restlessness, and hyperactivity. RABV was detected in her saliva by high-throughput sequencing Next Generation Sequencing (NGS) and polymerase chain reaction (PCR). Based on typical clinical symptoms and the result of NGS and PCR, the patient was diagnosed as a confirmed case of rabies. Hemodialysis combined with antiviral therapy and intensive care unit (ICU) treatment can effectively relieve circulatory failure, respiratory failure, and renal failure. Finally, she died of brain death on the 34th day of admission. The case report showed that blood purification was positive for rabies-induced organ failure. Blood purification combined with antiviral therapy can prolong the lives of patients with rabies to some extent.

Rotenone-Induced Neurodegeneration Is Enabled by a p38-Parkin-ROS Signaling Feedback Loop.

Rotenone, a component of pesticides, is widely used in agriculture and potentially causes Parkinson's disease (PD). However, the regulatory mechanisms of rotenone-induced PD are unclear. Here, we revealed a novel feedback mechanism of p38-Parkin-ROS regulating rotenone-induced PD. Rotenone treatment led to not only the activation of p38 but also Parkin inactivation and reactive oxygen species (ROS) overproduction in SN4741 cells. Meanwhile, p38 activation regulated Parkin phosphorylation at serine 131 to disrupt Parkin-mediated mitophagy. Notably, both p38 inhibition and Parkin overexpression decreased ROS levels. Additionally, the ROS inhibitor N-acetyl-l-cysteine (NAC) inhibited p38 and activated Parkin-mediated mitophagy. Both p38 inhibition and the ROS inhibitor NAC exerted a protective effect by restoring cell death and mitochondrial function in rotenone-induced PD models. Based on these results, the p38-Parkin-ROS signaling pathway is involved in neurodegeneration. This pathway represents a valuable treatment strategy for rotenone-induced PD, and our study provides basic research evidence for the safe use of rotenone in agriculture.

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.

The impact of tracheotomy on levels of procalcitonin in patients without sepsis: a prospective study.

OBJECTIVE: Procalcitonin is a reliable biomarker of infection and sepsis. We aimed to determine whether tracheotomy influences the procalcitonin concentrations in patients without sepsis and assess whether operative duration and procedure affect the peak procalcitonin level. METHODS: A total of 38 non-septic patients who required a tracheotomy underwent either a percutaneous dilatational tracheotomy (n=19) or a surgical tracheotomy (n=19). Procalcitonin levels were measured at the beginning of the tracheotomy and at 2 h, 4 h, 8 h, 24 h, 48 h and 72 h after the procedure. RESULTS: The baseline procalcitonin concentration before the tracheotomy was 0.24 ± 0.13 ng/mL. The postoperative levels increased rapidly, with a 4-fold elevation after 2 h, reaching a peak 4 h later with a 5-fold increase over baseline. Thereafter, the levels gradually returned to 2-fold greater than the baseline level within 72 h. The peak levels of procalcitonin showed a significant positive correlation with operative durations (r=0.710, p<0.001) and procedures (rho=0.670, p<0.001). CONCLUSION: In patients without sepsis, tracheotomy induces a rapid release of serum procalcitonin, and the operative duration and procedure have significant impacts on the peak procalcitonin levels. Thus, the nonspecific increase in procalcitonin levels following tracheotomy needs to be considered when this measure is used to evaluate infection.

The impact of tracheotomy on levels of procalcitonin in patients without sepsis: a prospective study

OBJECTIVE:Procalcitonin is a reliable biomarker of infection and sepsis. We aimed to determine whether tracheotomy influences the procalcitonin concentrations in patients without sepsis and assess whether operative duration and procedure affect the peak procalcitonin level.METHODS:A total of 38 non-septic patients who required a tracheotomy underwent either a percutaneous dilatational tracheotomy (n=19) or a surgical tracheotomy (n=19). Procalcitonin levels were measured at the beginning of the tracheotomy and at 2 h, 4 h, 8 h, 24 h, 48 h and 72 h after the procedure.RESULTS:The baseline procalcitonin concentration before the tracheotomy was 0.24±0.13 ng/mL. The postoperative levels increased rapidly, with a 4-fold elevation after 2 h, reaching a peak 4 h later with a 5-fold increase over baseline. Thereafter, the levels gradually returned to 2-fold greater than the baseline level within 72 h. The peak levels of procalcitonin showed a significant positive correlation with operative durations (r=0.710, p<0.001) and procedures (rho=0.670, p<0.001).CONCLUSION:In patients without sepsis, tracheotomy induces a rapid release of serum procalcitonin, and the operative duration and procedure have significant impacts on the peak procalcitonin levels. Thus, the nonspecific increase in procalcitonin levels following tracheotomy needs to be considered when this measure is used to evaluate infection.