Andrographolide ameliorates sepsis-induced acute lung injury by promoting autophagy in alveolar macrophages via the RAGE/PI3K/AKT/mTOR pathway.

Autophagy in alveolar macrophages (AMs) is an important mechanism for maintaining immune homeostasis and normal lung tissue function, and insufficient autophagy in AMs may mediate the development of sepsis-induced acute lung injury (SALI). Insufficient autophagy in AMs and the activation of the NLRP3 inflammasome were observed in a mouse model with SALI induced by cecal ligation and puncture (CLP), resulting in the release of a substantial quantity of proinflammatory factors and the formation of SALI. However, after andrographolide (AG) intervention, autophagy in AMs was significantly promoted, the activation of the NLRP3 inflammasome was inhibited, the release of proinflammatory factors and pyroptosis were suppressed, and SALI was then ameliorated. In the MH-S cell model stimulated with LPS, insufficient autophagy was discovered to promote the overactivation of the NLRP3 inflammasome. AG was found to significantly promote autophagy, inhibit the activation of the NLRP3 inflammasome, and attenuate the release of proinflammatory factors. The primary mechanism of AG promoting autophagy was to inhibit the activation of the PI3K/AKT/mTOR pathway by binding RAGE to the membrane. In addition, it inhibited the activation of the NLRP3 inflammasome to ameliorate SALI. Our findings suggest that AG promotes autophagy in AMs through the RAGE/PI3K/AKT/mTOR pathway to inhibit the activation of the NLRP3 inflammasome, remodel the functional homeostasis of AMs in SALI, and exert anti-inflammatory and lung-protective effects. It has also been the first to suggest that RAGE is likely a direct target through which AG regulates autophagy, providing theoretical support for a novel therapeutic strategy in sepsis.

Chromofungin, a chromogranin A-derived peptide, protects against sepsis-induced acute lung injury by inhibiting LBP/TLR4-dependent inflammatory signaling.

Chromofungin (CHR) is a biologically active peptide derived from chromogranin A that exhibits anti-inflammatory effects. However, it remains unclear whether and how CHR protects against sepsis-induced acute lung injury (ALI). A murine model of sepsis-induced ALI was established through cecal ligation and puncture, with intraperitoneal injection of CHR. Lung inflammation and macrophage polarization were examined by measuring the levels of cytokines and markers of M1 (CD86, inducible nitric oxide synthase [iNOS]) or M2 macrophages (arginase-1 [Arg1], resistin-like molecule α1 [Fizz1] and CD206). In vitro, mouse MH-S cells pretreated with CHR was employed to explore the interplay between the lipopolysaccharide-binding protein (LBP)/toll-like receptor 4 (TLR4) signaling pathway and M1/M2 polarity. The results revealed CHR's ability to enhance the 7-day survival rate and protect lung pathological injury in sepsis-induced ALI. CHR increased the expression of interleukin-4 and interleukin-10 but decreased the expression of tumour necrosis factor-α and interleukin-1ß. In addition, CHR notably facilitated M2 macrophage polarization, while significantly suppressingM1 polarization of alveolar macrophages. Mechanistic investigations delineated CHR's role in macrophage polarization by downregulating nuclear factor-κB expression through modulation of the LBP/TLR4 signaling pathway. Therefore, CHR may represent a novel strategy for the prevention of sepsis-induced ALI.

Synergistic effect of bovine cateslytin-loaded nanoparticles combined with ultrasound against Candida albicans biofilm.

Purpose: To investigate the synergistic effect of bovine cateslytin-loaded nanoparticles (bCAT-NPs) combined with ultrasound against Candida albicans biofilm and uncover the underlying mechanism. Methods: bCAT-NPs were prepared by the double emulsion method, and toxicity was observed by the hemolysis ratio. The metabolic activity and viable cell biomass, morphology and membrane permeability of C. albicans biofilm were observed. The expression of ALS3 mRNA, the content of reactive oxygen species, was detected. Finally, bCAT structure was analyzed. Results & conclusion: The hemolysis ratio of the bCAT-NPs group was significantly lower than that of the bCAT group. bCAT-NPs combined with ultrasound significantly reduced biofilm metabolic activity, inhibited the formation of hyphae, decreased the expression of ALS3 mRNA and increased the intracellular reactive oxygen species content. In the in vivo experiments, the colony-forming units/ml in the ultrasound+bCAT-NPs group decreased, and a few planktonic fungal cells were observed.

Chromogranin A-derived peptide CGA47-66 protects against septic brain injury by reducing blood-brain barrier damage through the PI3K/AKT pathway.

CGA47-66 (Chromofungin, CHR), is a peptide derived from the N-terminus of chromogranin A (CgA), has been proven to inhibit the lipopolysaccharide (LPS)-induced brain injury. However, the underlying mechanism is still unknown. We found that CGA47-66 exerted a protective effect on cognitive impairment by inhibiting the destruction of the blood-brain barrier (BBB) in the LPS-induced sepsis mice model. In addition, the hCMEC/D3 cell line was used to establish an in vitro BBB model. Under LPS stimulation, CGA47-66 could significantly alleviate the hyperpermeability of the BBB, the destruction of tight junction proteins, and the rearrangement of F-actin. To investigate the underlying mechanism, we used LY294002, a PI3K inhibitor, which partially reduced the protective effect of CGA47-66 on the integrity of BBB. Indicating that the PI3K/AKT pathway plays a vital role in the brain-protective function of CGA47-66, which might be a potential therapeutic target for septic brain injury.

Pulmonary embolism secondary to deep venous thrombosis: A retrospective and observational study for clinical characteristics and risk stratification.

OBJECTIVE: To investigate the risk factors, predilection sites in pulmonary embolism (PE) patients caused by deep venous thrombosis (DVT) and explore the value of scoring systems in assessing the risk of PE in DVT patients. METHODS: A total of 692 DVT patients were enrolled, and divided into no pulmonary embolism (NPE, 226, 32.66%), silent pulmonary embolism (SPE, 330, 47.67%) and featuring pulmonary embolism (FPE, 136, 19.65%) groups. For each group, the differences of clinical data and PE locations were compared, and the risk factors of PE secondary to DVT were analyzed. The predictive value of the scoring system for the diagnosis of PE and FPE was evaluated. RESULTS: PE presented more in the bilateral pulmonary arteries (PAs) (249, 53.43%) and has no significant difference in PESI scores in different locations. Gender, DVT locations, and previous surgery were the independent risk factors of PE. DVT locations, previous history of COPD, and previous surgical interventions were the independent risk factors of FPE. The results for areas under the ROC curves were: AUC(Wells) = 0.675, AUC (Revised Geneva) = 0.601, AUC(D-dimer) = 0.595 in the PE group; AUC(Wells) = 0.722, AUC (Revised Geneva) = 0.643, AUC(D-dimer) = 0.557 in the FPE group. CONCLUSIONS: PE secondary to DVT mostly occurs in the bilateral PAs. Male gender, DVT locations, and previous surgery increased the risk of PE. The Wells scoring system was more advantageous for evaluating the diagnosis of PE in patients with DVT.

[A study of inhibitory effect of chromogranin A derived peptide CGA(47 _ 66) on hyper - permeability of endothelium induced by serum of septic patient].

OBJECTIVE: To explore the role of chromogranin A ( CGA) derived peptide CGA47~ ( Chromfungin, CHR) on septic serum induced high permeability of vascular endothelial cells. METHODS: Human umbilical venous endothelial cell line (EA.hy926 cells) was exposed to CHR, serum of septic shock patient, and tumor necrosis factor-a (TNF-a) respectively. Methyl thiazolyl tetrazolium (MTT) method, Transwell assay and immunofluorescence were performed to determine cell viability (absorbance (A) value J, permeability of monolayer endothelial cells (A value) , and the morphological characteristic and distribution ofF -actin respectively. RESULTS: Compared with the blank control group, when EA.hy926 were exposed to CHR with 1, 10, 100 nmol/L the cell activity was not significantly affected (A value: 1.219 ± 0.253, 1.179 ± 0.065, 1.179 ± 0.062 vs. 1.306 ± 0.162, all P>0.05), while when the cells was exposed to CHR in 1 000 nmol/L the cell activity was significantly inhibited (A value: 1.049 ± 0.256 vs. 1.306 ± 0.162, t=-2.390, P=0.031 ). Compared with blank control group, when the cells were exposed to CHR of 1, 10, 100 nmol/L a significant decrease in permeability in EA.hy926 cells was observed (A value: 1.619 ± 0.324, 1.496 ± 0.356, 1.132 ± 0.280 vs. 2.315 ± 0.440, P<0.05 or P<0.01 ). Treatment of septic shock patient's serum or TNF-a to EA. hy926 produced an obvious increase in its permeability (septic serum group A value: 1.204 ± 0.248 vs. 0.277 ± 0.017, P<0.01; TNF-a group A value: 2.485 ± 0.113 vs. 1.602 ± 0.679, P<0.05). High-permeability induced by TNF-a or septic shock patient's serum was alleviated hy CHR in the concentration of 1, 10, 100 nmol/L in a dose-dependent manner (septic serum + CHR group A value: 0.299 ± 0.065, 0.224 ± 0.028, 0.131 ± 0.015 vs. 1.204 ± 0.248; TNF -a + CHR group A value: 1.995 ± 0.394, 1.920 ± 0.096, 1.744 ± 0.475 vs. 2.485 ± 0.113, P<0.05 or P<0.01 ). Under a laser scanning confocal microscope, it was found that the F-actin cytoskeleton of EA.hy926 cells was redistributed, and more stress fibers were found in the septic shock patient's serum group and TNF-α group, while CHR obviously alleviated the above effects induced by septic shock patient's serum or TNF-α. CONCLUSION: In a dose-dependent manner, CHR may inhibit increased permeability of vascular endothelial cells induced by septic shock patient's serum, its underlying mechanism may be related to inhibition of the effect of TNF-α.