Plasma Proteomics Identify Biomarkers and Pathogenesis of COVID-19.

The coronavirus disease 2019 (COVID-19) pandemic is a global public health crisis. However, little is known about the pathogenesis and biomarkers of COVID-19. Here, we profiled host responses to COVID-19 by performing plasma proteomics of a cohort of COVID-19 patients, including non-survivors and survivors recovered from mild or severe symptoms, and uncovered numerous COVID-19-associated alterations of plasma proteins. We developed a machine-learning-based pipeline to identify 11 proteins as biomarkers and a set of biomarker combinations, which were validated by an independent cohort and accurately distinguished and predicted COVID-19 outcomes. Some of the biomarkers were further validated by enzyme-linked immunosorbent assay (ELISA) using a larger cohort. These markedly altered proteins, including the biomarkers, mediate pathophysiological pathways, such as immune or inflammatory responses, platelet degranulation and coagulation, and metabolism, that likely contribute to the pathogenesis. Our findings provide valuable knowledge about COVID-19 biomarkers and shed light on the pathogenesis and potential therapeutic targets of COVID-19.

Risk factors for invasive pulmonary aspergillosis in patients with severe fever with thrombocytopenia syndrome: A multicenter retrospective study.

Invasive pulmonary aspergillosis (IPA) is a life-threatening complication in patients with severe fever with thrombocytopenia syndrome (SFTS), yet SFTS-associated IPA (SAPA)'s risk factors remain undefined. A multicenter retrospective cohort study across Hubei and Anhui provinces (May 2013-September 2022) utilized least absolute shrinkage and selection operator (LASSO) regression for variable selection. Multivariable logistic regression identified independent predictors of SAPA, Cox regression highlighted mortality-related risk factors. Of the 1775 screened SFTS patients, 1650 were included, with 169 developing IPA, leading to a 42-day mortality rate of 26.6% among SAPA patients. Multivariable logistic regression revealed SAPA risk factors including advanced age, petechia, hemoptysis, tremor, low albumin levels, elongated activated partial thromboplastin time (APTT), intensive care unit (ICU) admission, glucocorticoid usage, intravenous immunoglobulin (IVIG) and prolonged hospital stays. Cox regression identified predictors of 42-day mortality, including ecchymosis at venipuncture sites, absence of ICU admission, elongated prothrombin time (PT), vasopressor and glucocorticoid use, non-antifungals. Nomograms constructed on these predictors registered concordance indexes of 0.855 (95% CI: 0.826-0.884) and 0.778 (95% CI: 0.702-0.854) for SAPA onset and 42-day mortality, respectively. Lower survival rates for SAPA patients treated with glucocorticoids (p < 0.001) and improved 14-day survival with antifungal therapy (p = 0.036). Improving IPA management in SFTS-endemic areas is crucial, with effective predictive tool.

NLRC3 expression in macrophage impairs glycolysis and host immune defense by modulating the NF-κB-NFAT5 complex during septic immunosuppression.

Impairment of innate immune cell function and metabolism underlies immunosuppression in sepsis; however, a promising therapy to orchestrate this impairment is currently lacking. In this study, high levels of NOD-like receptor family CARD domain containing-3 (NLRC3) correlated with the glycolytic defects of monocytes/macrophages from septic patients and mice that developed immunosuppression. Myeloid-specific NLRC3 deletion improved macrophage glycolysis and sepsis-induced immunosuppression. Mechanistically, NLRC3 inhibits nuclear factor (NF)-κB p65 binding to nuclear factor of activated T cells 5 (NFAT5), which further controls the expression of glycolytic genes and proinflammatory cytokines of immunosuppressive macrophages. This is achieved by decreasing NF-κB activation-co-induced by TNF-receptor-associated factor 6 (TRAF6) or mammalian target of rapamycin (mTOR)-and decreasing transcriptional co-activator p300 activity by inducing NLRC3 sequestration of mTOR and p300. Genetic inhibition of NLRC3 disrupted the NLRC3-mTOR-p300 complex and enhanced NF-κB binding to the NFAT5 promoter in concert with p300. Furthermore, intrapulmonary delivery of recombinant adeno-associated virus harboring a macrophage-specific NLRC3 deletion vector significantly improved the defense of septic mice that developed immunosuppression upon secondary intratracheal bacterial challenge. Collectively, these findings indicate that NLRC3 mediates critical aspects of innate immunity that contribute to an immunocompromised state during sepsis and identify potential therapeutic targets.

Mechanical Properties and Fatigue Life Analysis of Motion Cables in Sensors under Cyclic Loading.

Motion cables, which are widely used in aero-engine sensors, are critical components that determine sensor stability. Because motion cables have unique motion characteristics, the study of their mechanical properties and reliability is very important. In addition, motion cables are complex in structure and cannot be applied to conventional fixed cable research methods. In this study, a new approach is proposed to introduce the theory of anisotropic composites into a simplified cable model, so that the cable is both physically conditioned and has good mechanical properties. While applying the theory of anisotropic composites, the forces of tension and torsion are considered in a motion cable under the combined action. In this context, the reliability of the structure is the fatigue life of the cable. In this paper, the mechanical properties and fatigue life of motion cables are investigated using the finite element method at different inclination angles and fixation points. The simulation results show that there is a positive correlation between the inclination angle and the extreme stress in the motion cables, and the optimal inclination angle of 0° is determined. The number of fixing points should be reduced to minimize the additional moments generated during the movement and to ensure proper movement of the cables. The optimal configuration is a 0° inclination angle and two fixing points. Subsequently, the fatigue life under these optimal conditions is analyzed. The results show that the high-stress zone corresponds to the location of the short-fatigue life, which is the middle of the motion cables. Therefore, minimizing the inclination angle and the number of fixing points of the motion cables may increase their fatigue life and thus provide recommendations for optimizing their reliability.

NLRC3 Participates in Inhibiting the Pulmonary Inflammatory Response of Sepsis-Induced Acute Lung Injury.

Acute lung injury (ALI) progresses rapidly, is difficult to treat, and has a high fatality rate. The excessive inflammatory response is an important pathological mechanism of ALI. NLRC3 (NLR family CARD domain-containing 3), a non-inflammasome member of the NLR family, has been found that it could negatively regulates various biological pathways associated with inflammatory response, such as NF-κB (nuclear factor kappa B), PI3K (Phosphatidylinositol 3'-kinase)-Akt (protein kinase B)-mTOR (mammalian target of the rapamycin), and STING (stimulator of interferon genes) pathways, which are responsible for the progression of pulmonary inflammation and participate in regulating the pathological progression of ALI. However, the effects of NLRC3 in sepsis-induced pathological injury of lung tissue remain unclear. In this study, we aimed to investigate the potential effects of NLRC3 in the sepsis-induced ALI. To investigate whether NLRC3 participates in inhibiting the pulmonary inflammatory response of sepsis-induced ALI. Sepsis-induced ALI mice models were established by intrabronchial injection of lipopolysaccharide (LPS) or cecum ligation and puncture (CLP). The lentivirus with overexpression of NLRC3 (LV-NLRC3) and downregulation of NLRC3 (LV-NLRC3-RNAi) were transfected to LPS-induced ALI mice. The expression of NLRC3 was upregulated or downregulated in the lung tissue of sepsis-induced ALI mice. Transfection with NLRC3-overexpression lentivirus significantly decreased inflammatory response in the lung of LPS-induced ALI mice in contrast to the control group. By transfection with NLRC3-silencing lentivirus, the inflammatory response in LPS-induced ALI mice was aggravated. Our study provides evidence of the protective effect of NLRC3 in sepsis-induced ALI by inhibiting excessive inflammatory response of the lung tissue.AbbreviationsAcute lung injury: ALI; intensive care units: ICU; lipopolysaccharide: LPS; acute respiratory distress syndrome: ARDS; bronchoalveolar lavage fluid: BALF; nucleotide-binding oligomerization domain-like receptors: NLRs; NLR family CARD domain containing 3: NLRC3; nuclear factor kappa B: NF-κB; tumor necrosis factor receptor-associated factor 6: TRAF6; Phosphatidylinositol 3'-kinase: PI3K; protein kinase B: Akt; mammalian target of the rapamycin: mTOR; stimulator of interferon genes: STING; TANK-binding kinase 1: TBK1; type I interferon: IFN-I; toll-like receptors: TLRs; tumor necrosis factor: TNF; interleukin: IL; NOD-like receptor protein 3: NLRP3; enhanced green fluorescent protein: EGFP; lentivirus: LV; phosphate-buffered saline: PBS; intrabronchial: i.t.; cecum ligation and puncture: CLP; wet/dry: W/D; Real time polymerase chain reaction: RT-PCR; enzyme-linked immunosorbent assay: ELISA; hematoxylin and eosin: H&E; radio immunoprecipitation assay: RIPA; sodium dodecyl sulfate polyacrylamide gel electrophoresis: SDS-PAGE; polyvinylidene fluoride: PVDF; glyceraldehyde 3-phosphate dehydrogenase: GAPDH; bovine serum albumin: BSA; Tris buffered saline containing Tween 20: TBST; standard deviation: SD; one-way analysis of variance: ANOVA; janus kinase 2: JAK2; activators of transcription 3: STAT3; pathogen associated molecular patterns: PAMPs; danger associated molecular patterns: DAMPs.

Effects of airway pressure release ventilation on lung physiology assessed by electrical impedance tomography in patients with early moderate-to-severe ARDS.

OBJECTIVE: The aim of this study was to investigate the physiological impact of airway pressure release ventilation (APRV) on patients with early moderate-to-severe acute respiratory distress syndrome (ARDS) by electrical impedance tomography (EIT). METHODS: In this single-center prospective physiological study, adult patients with early moderate-to-severe ARDS mechanically ventilated with APRV were assessed by EIT shortly after APRV (T0), and 6 h (T1), 12 h (T2), and 24 h (T3) after APRV initiation. Regional ventilation and perfusion distribution, dead space (%), shunt (%), and ventilation/perfusion matching (%) based on EIT measurement at different time points were compared. Additionally, clinical variables related to respiratory and hemodynamic condition were analyzed. RESULTS: Twelve patients were included in the study. After APRV, lung ventilation and perfusion were significantly redistributed to dorsal region. One indicator of ventilation distribution heterogeneity is the global inhomogeneity index, which decreased gradually [0.61 (0.55-0.62) to 0.50 (0.42-0.53), p < 0.001]. The other is the center of ventilation, which gradually shifted towards the dorsal region (43.31 ± 5.07 to 46.84 ± 4.96%, p = 0.048). The dorsal ventilation/perfusion matching increased significantly from T0 to T3 (25.72 ± 9.01 to 29.80 ± 7.19%, p = 0.007). Better dorsal ventilation (%) was significantly correlated with higher PaO2/FiO2 (r = 0.624, p = 0.001) and lower PaCO2 (r = -0.408, p = 0.048). CONCLUSIONS: APRV optimizes the distribution of ventilation and perfusion, reducing lung heterogeneity, which potentially reduces the risk of ventilator-induced lung injury.

Remimazolam besylate versus propofol for deep sedation in critically ill patients: a randomized pilot study.

OBJECTIVE: To compare the efficacy and safety of remimazolam besylate and propofol for deep sedation in critically ill patients. METHODS: In this single-center, prospective, randomized, controlled pilot study, patients in the intensive care unit (ICU) requiring deep sedation were randomized to receive remimazolam besylate or propofol intravenously. Deep sedation was defined as a Richmond Agitation and Sedation Scale (RASS) score of - 4 or - 5. Sedation depth was monitored using RASS and Narcotrend Index (NI). The primary outcome was the percentage of time within the target sedation range without rescue sedation. The secondary outcomes included ventilator-free hours within 7 days, successful extubation, length of ICU stay, and 28-day mortality. Adverse events during the interventional period were also recorded. RESULTS: Thirty patients were assigned to each group. The median (IQR) RASS score was - 5.0 (- 5.0, - 4.0), and the median (IQR) NI value was 29.0 (21.0, 37.0) during the intervention period. Target RASS was reached a median of 100% of the sedation time in the two groups. No significant differences were observed in ventilator-free hours within 7 days, successful extubation, length of ICU stay, or 28-day mortality among groups. Hypotension occurred in 16 (53.3%) patients of remimazolam group and 18 (60.0%) patients of propofol group (p > 0.05). No patient experienced bradycardia. CONCLUSIONS: Remimazolam besylate appears to be an effective and safe agent for short-term deep sedation in critically ill patients. Our findings warrant large sample-sized randomized clinical trials.

Remimazolam besylate versus propofol for long-term sedation during invasive mechanical ventilation: a pilot study.

OBJECTIVE: The aim of this study was to evaluate the efficacy and safety of remimazolam besylate compared with propofol in maintaining mild-to-moderate sedation in patients receiving long-term mechanical ventilation. METHODS: In this single-centered randomized pilot study, adult patients mechanically ventilated longer than 24 h were randomized to receive remimazolam besylate or propofol. The target sedation range was - 3 to 0 on the Richmond Agitation and Sedation Scale (RASS). The primary outcome was the percentage of time in the target sedation range without rescue sedation. The secondary outcomes were ventilator-free days at day 7, the length of ICU stay and 28-day mortality. RESULTS: Thirty patients were assigned to each group. No difference was identified between the remimazolam group and propofol group in median age [60.0 (IQR, 51.5-66.3) years vs. 64.0 (IQR, 55.0-69.3) years, respectively, p = 0.437] or the median duration of study drug infusion [55.0 (IQR, 28.3-102.0) hours vs. 41.0 (IQR, 24.8-74.3) hours, respectively, p = 0.255]. The median percentage of time in the target RASS range without rescue sedation was similar in remimazolam and propofol groups [73.2% (IQR, 41.5-97.3%) vs. 82.8% (IQR, 65.6-100%), p = 0.269]. No differences were identified between the two groups in terms of ventilator-free days at day 7, length of ICU stay, 28-day mortality or adverse events. CONCLUSIONS: This pilot study suggested that remimazolam besylate was effective and safe for long-term sedation in mechanically ventilated patients compared with propofol.

Application of POCUS in patients with COVID-19 for acute respiratory distress syndrome management: a narrative review.

COVID-19 has inflicted the world for over two years. The recent mutant virus strains pose greater challenges to disease prevention and treatment. COVID-19 can cause acute respiratory distress syndrome (ARDS) and extrapulmonary injury. Dynamic monitoring of each patient's condition is necessary to timely tailor treatments, improve prognosis and reduce mortality. Point-of-care ultrasound (POCUS) is broadly used in patients with ARDS. POCUS is recommended to be performed regularly in COVID-19 patients for respiratory failure management. In this review, we summarized the ultrasound characteristics of COVID-19 patients, mainly focusing on lung ultrasound and echocardiography. Furthermore, we also provided the experience of using POCUS to manage COVID-19-related ARDS.

Role of Cholinergic Anti-Inflammatory Pathway in Protecting Sepsis-Induced Acute Lung Injury through Regulation of the Conventional Dendritic Cells.

BACKGROUND: The cholinergic anti-inflammatory pathway connects the immune response system and the nervous system via the vagus nerve. The key regulatory receptor is the α7-subtype of the nicotinic acetylcholine receptor (α7nAChR). Cholinergic anti-inflammatory pathway has been proved to be effective in suppressing the inflammation responses in acute lung injury (ALI). Dendritic cells (DCs), the important antigen-presenting cells, also express the α7nAChR. Past studies have indicated that reducing the quantity of mature conventional DCs and inhibiting the maturation of pulmonary DCs may prove effective for the treatment of ALI. However, the effects of cholinergic anti-inflammatory pathway on maturation, function, and quantity of DCs and conventional DCs in ALI remain unclear. OBJECTIVE: It was hypothesized that cholinergic anti-inflammatory pathway may inhibit the inflammatory response of ALI by regulating maturation, phenotype, and quantity of DCs and conventional DCs. METHODS: GTS-21 (GTS-21 dihydrochloride), an α7nAchR agonist, was prophylactically administered in sepsis-induced ALI mouse model and LPS-primed bone marrow-derived dendritic cells. The effects of GTS-21 were observed with respect to maturation, phenotype, and quantity of DCs, conventional DCs, and conventional DCs2 (type 2 conventional DCs) and the release of DC-related proinflammatory cytokines in vivo and in vitro. RESULTS: The results of the present study revealed that GTS-21 treatment decreased the maturation of DCs and the production of DC-related proinflammatory cytokines in vitro and in sepsis-induced ALI mouse model; it reduced the quantity of CD11c+MHCII+ conventional DCs and CD11c+CD11b+ conventional DCs2 in vivo experiment. CONCLUSIONS: Cholinergic anti-inflammatory pathway contributes to the reduction in the inflammatory response in ALI by regulating maturation, phenotype, and quantity of DCs, conventional DCs, and conventional DCs2.

Characteristics of Liver Function in Patients With SARS-CoV-2 and Chronic HBV Coinfection.

BACKGROUND & AIMS: Coronavirus disease 2019 (COVID-19) is a major global health threat. We aimed to describe the characteristics of liver function in patients with SARS-CoV-2 and chronic hepatitis B virus (HBV) coinfection. METHODS: We enrolled all adult patients with SARS-CoV-2 and chronic HBV coinfection admitted to Tongji Hospital from February 1 to February 29, 2020. Data of demographic, clinical characteristics, laboratory tests, treatments, and clinical outcomes were collected. The characteristics of liver function and its association with the severity and prognosis of disease were described. RESULTS: Of the 105 patients with SARS-CoV-2 and chronic HBV coinfection, elevated levels of liver test were observed in several patients at admission, including elevated levels of alanine aminotransferase (22, 20.95%), aspartate aminotransferase (29, 27.62%), total bilirubin (7, 6.67%), gamma-glutamyl transferase (7, 6.67%), and alkaline phosphatase (1, 0.95%). The levels of the indicators mentioned above increased substantially during hospitalization (all P < .05). Fourteen (13.33%) patients developed liver injury. Most of them (10, 71.43%) recovered after 8 (range 6-21) days. Notably the other, 4 (28.57%) patients rapidly progressed to acute-on-chronic liver failure. The proportion of severe COVID-19 was higher in patients with liver injury (P = .042). Complications including acute-on-chronic liver failure, acute cardiac injury and shock happened more frequently in patients with liver injury (all P < .05). The mortality was higher in individuals with liver injury (28.57% vs 3.30%, P = .004). CONCLUSION: Liver injury in patients with SARS-CoV-2 and chronic HBV coinfection was associated with severity and poor prognosis of disease. During the treatment of COVID-19 in chronic HBV-infected patients, liver function should be taken seriously and evaluated frequently.

ATP/P2X7r axis mediates the pathological process of allergic asthma by inducing M2 polarization of alveolar macrophages.

Recent studies revealed that macrophages are polarized towards the M2 phenotype in an ovalbumin (OVA)-induced asthmatic model. Alveolar macrophages (AMs) are immune barriers in alveoli to various pathogens in the respiratory tract; AMs suppress Th2 cell proliferation, inhibit interleukin (IL)-4, IL-5, and IL-13 secretion, and protect against airway hyperresponsiveness in allergic asthma. However, the polarization status and effects of different types of AMs in the pathogenesis of asthma are not known. ATP/P2X7r, expressed mainly on macrophages and dendritic cells, is associated with acute and chronic asthmatic airway inflammation and Th2 immune responses in mice and humans and functions by activating the NLRP3 inflammasome complex and inducing proinflammatory cytokine release (IL-1ß and IL-18). Therefore, we evaluated the association between the ATP/P2X7r axis and different types of AMs in the pathology of allergic asthma. A murine AM-depleted asthma model was established by administration of clodronate-encapsulated liposomes, and M1-or M2-AMs were adoptively transferred to confirm the effects of different AMs in allergic asthma. Brilliant Blue G and BzATP were administered to OVA/HDM-induced mice in vivo. Lipopolysaccharide + OVA, ATP, Brilliant Blue G, and BzATP were used to stimulate AMs isolated from control and asthmatic mice. We found that selective depletion of AMs aggravated lung inflammation in asthmatic mice. Further, M2-type AMs may play a key role in mediating asthmatic inflammatory responses via the adoptive transfer of M2-type AMs to AM-depleted asthmatic mice, and the phenotype of AMs differentiated to M2 type in asthma. P2X7r expression in M2-type AMs was higher than that in M1-type AMs. Activating P2X7r induced polarization of M2-type AMs and inhibited polarization of M1-type AMs, while blockage of P2X7r had the opposite effect. The ATP/P2X7r axis may participate in the pathogenesis of asthma by mediating the M2-type AM polarization.

Acute Physiology and Chronic Health Evaluation II Score as a Predictor of Hospital Mortality in Patients of Coronavirus Disease 2019.

OBJECTIVES: Coronavirus disease 2019 has emerged as a major global health threat with a great number of deaths in China. We aimed to assess the association between Acute Physiology and Chronic Health Evaluation II score and hospital mortality in patients with coronavirus disease 2019, and to compare the predictive ability of Acute Physiology and Chronic Health Evaluation II score, with Sequential Organ Failure Assessment score and Confusion, Urea, Respiratory rate, Blood pressure, Age 65 (CURB65) score. DESIGN: Retrospective observational cohort. SETTING: Tongji Hospital in Wuhan, China. SUBJECTS: Confirmed patients with coronavirus disease 2019 hospitalized in the ICU of Tongji hospital from January 10, 2020, to February 10, 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 178 potentially eligible patients with symptoms of coronavirus disease 2019, 23 patients (12.92%) were diagnosed as suspected cases, and one patient (0.56%) suffered from cardiac arrest immediately after admission. Ultimately, 154 patients were enrolled in the analysis and 52 patients (33.77%) died. Mean Acute Physiology and Chronic Health Evaluation II score (23.23 ± 6.05) was much higher in deaths compared with the mean Acute Physiology and Chronic Health Evaluation II score of 10.87 ± 4.40 in survivors (p < 0.001). Acute Physiology and Chronic Health Evaluation II score was independently associated with hospital mortality (adjusted hazard ratio, 1.07; 95% CI, 1.01-1.13). In predicting hospital mortality, Acute Physiology and Chronic Health Evaluation II score demonstrated better discriminative ability (area under the curve, 0.966; 95% CI, 0.942-0.990) than Sequential Organ Failure Assessment score (area under the curve, 0.867; 95% CI, 0.808-0.926) and CURB65 score (area under the curve, 0.844; 95% CI, 0.784-0.905). Based on the cut-off value of 17, Acute Physiology and Chronic Health Evaluation II score could predict the death of patients with coronavirus disease 2019 with a sensitivity of 96.15% and a specificity of 86.27%. Kaplan-Meier analysis showed that the survivor probability of patients with coronavirus disease 2019 with Acute Physiology and Chronic Health Evaluation II score less than 17 was notably higher than that of patients with Acute Physiology and Chronic Health Evaluation II score greater than or equal to 17 (p < 0.001). CONCLUSIONS: Acute Physiology and Chronic Health Evaluation II score was an effective clinical tool to predict hospital mortality in patients with coronavirus disease 2019 compared with Sequential Organ Failure Assessment score and CURB65 score. Acute Physiology and Chronic Health Evaluation II score greater than or equal to 17 serves as an early warning indicator of death and may provide guidance to make further clinical decisions.

Clinical course and predictors of 60-day mortality in 239 critically ill patients with COVID-19: a multicenter retrospective study from Wuhan, China.

BACKGROUND: The global numbers of confirmed cases and deceased critically ill patients with COVID-19 are increasing. However, the clinical course, and the 60-day mortality and its predictors in critically ill patients have not been fully elucidated. The aim of this study is to identify the clinical course, and 60-day mortality and its predictors in critically ill patients with COVID-19. METHODS: Critically ill adult patients admitted to intensive care units (ICUs) from 3 hospitals in Wuhan, China, were included. Data on demographic information, preexisting comorbidities, laboratory findings at ICU admission, treatments, clinical outcomes, and results of SARS-CoV-2 RNA tests and of serum SARS-CoV-2 IgM were collected including the duration between symptom onset and negative conversion of SARS-CoV-2 RNA. RESULTS: Of 1748 patients with COVID-19, 239 (13.7%) critically ill patients were included. Complications included acute respiratory distress syndrome (ARDS) in 164 (68.6%) patients, coagulopathy in 150 (62.7%) patients, acute cardiac injury in 103 (43.1%) patients, and acute kidney injury (AKI) in 119 (49.8%) patients, which occurred 15.5 days, 17 days, 18.5 days, and 19 days after the symptom onset, respectively. The median duration of the negative conversion of SARS-CoV-2 RNA was 30 (range 6-81) days in 49 critically ill survivors that were identified. A total of 147 (61.5%) patients deceased by 60 days after ICU admission. The median duration between ICU admission and decease was 12 (range 3-36). Cox proportional-hazards regression analysis revealed that age older than 65 years, thrombocytopenia at ICU admission, ARDS, and AKI independently predicted the 60-day mortality. CONCLUSIONS: Severe complications are common and the 60-day mortality of critically ill patients with COVID-19 is considerably high. The duration of the negative conversion of SARS-CoV-2 RNA and its association with the severity of critically ill patients with COVID-19 should be seriously considered and further studied.

Vascular smooth muscle cell motility is mediated by a physical and functional interaction of Ca2+/calmodulin-dependent protein kinase IIδ2 and Fyn.

In vascular smooth muscle (VSM) cells, Ca(2+)/calmodulin-dependent protein kinase IIδ2 (CaMKIIδ2) activates non-receptor tyrosine kinases and EGF receptor, with a Src family kinase as a required intermediate. siRNA-mediated suppression of Fyn, a Src family kinase, inhibited VSM cell motility. Simultaneous suppression of both Fyn and CaMKIIδ2 was non-additive, suggesting coordinated regulation of cell motility. Confocal immunofluorescence microscopy indicated that CaMKIIδ2 and Fyn selectively (compared with Src) co-localized with the Golgi in quiescent cultured VSM cells. Stimulation with PDGF resulted in a rapid (<5 min) partial redistribution and co-localization of both kinases in peripheral membrane regions. Furthermore, CaMKIIδ2 and Fyn selectively (compared with Src) co-immunoprecipitated, suggesting a physical interaction in a signaling complex. Stimulation of VSM cells with ionomycin, a calcium ionophore, resulted in activation of CaMKIIδ2 and Fyn and disruption of the complex. Pretreatment with KN-93, a pharmacological inhibitor of CaMKII, prevented activation-dependent disruption of CaMKIIδ2 and Fyn, implicating CaMKIIδ2 as an upstream mediator of Fyn. Overexpression of constitutively active CaMKII resulted in the dephosphorylation of Fyn at Tyr-527, which is required for Fyn activation. Taken together, these data demonstrate a dynamic interaction between CaMKIIδ2 and Fyn in VSM cells and indicate a mechanism by which CaMKIIδ2 and Fyn may coordinately regulate VSM cell motility.

Endoplasmic reticulum stress-mediated autophagy protects against lipopolysaccharide-induced apoptosis in HL-1 cardiomyocytes.

Apoptosis of cardiomyocytes limits the contractile efficiency of the heart during sepsis. Prosurvival autophagy has been proposed as a novel mechanism to maintain normal heart function. Here, we demonstrated that autophagy was activated in lipopolysaccharide (LPS)-treated HL-1 cells, and it counteracted the LPS-induced apoptosis. We investigated further the mechanism by which LPS triggered autophagy in HL-1 cells. We discovered that endoplasmic reticulum (ER) stress played an important role in LPS-triggered autophagy. The ER activated a survival pathway through the ER-localized transmembrane protein PERK, which was essential for LPS-induced autophagy. Lipopolysaccharide increased expression of GRP78, phosphorylated PERK and phosphorylated eukaryotic initiation factor 2α. Similar results were observed after administration of tunicamycin, a well-known ER stressor. Most importantly, we found that 4-phenylbutyrate, an inhibitor of ER stress, suppressed LPS-activated autophagy in the presence of LPS in HL-1 cells. The same results were observed after small interfering RNA-mediated silencing of PERK protein. We also noticed that LPS-induced apoptosis appeared early, at 4 h. Our findings revealed that PERK, one arm of ER stress, facilitated survival of LPS-treated HL-1 cells by promoting autophagy, and could serve as a potential therapeutic strategy to alleviate septic myocardial dysfunction.

[Effect of sodium tanshinone II (A) sulfonate on Ang II -induced atrial fibroblast collagen synthesis and TGF-beta1 activation].

OBJECTIVE: To observe the effect of sodium tanshinone II (A) sulfonate (STS) on Ang II -induced atrial fibroblast collagen synthesis and TGF-beta1 activation. METHOD: Atrial fibroblasts of neonatal rats were cultured to determine the content of collagen protein. The original synthesis rate determined by the [3H]-proline incorporation method was taken as the index for myocardial fibrosis. The content of active TGF-beta1 and total TGF-beta1 in cell culture supernatants were tested and cultured by ELISA. The expression of thrombospondin-1 (TSP-1) was assessed by using Western blot. RESULT: Ang II could significantly increase the content of atrial fibroblast collagen and the collagen synthesis rate, the TSP-1 expression and the concentration of active TGF-beta1, without any obvious change in total TGF-beta1. After the STS treatment, all of the indexes, apart from total TGF-beta1, were obviously down-regulated. CONCLUSION: STS could decrease the secretion of Ang II -induced atrial fibroblast collagen and the synthesis rate. Its mechanism is related to the inhibition of TSP-1/TGF-beta1 pathway.