Protective Effect of Cobra Venom Factor on Lung Injury Induced by Cecal Puncture in Septic Rats

Objective:To investigate the protective effect of cobra venom factor(CVF)on lung tissue injury in rats with sepsis induced by cecal puncture,with a view to providing theoretical basis for the development of new anti-sepsis drugs.Methods:A total of 144 rats were randomly divided into sham operation group,sepsis group and CVF group,with 48 rats in each group.Cecal ligation and puncture(CLP)was used to establish a rat model of sepsis.And 8 rats were taken from each group at 2,4,8,12,16and 24 h to observe the differences in lung wet/dry weight ratio,lung histopathological changes,and serum inflammatory factor levels.Results:CVF treatment significantly alleviated the degree of pulmonary edema and swelling in septic rats,slowed down the trend of elevated lung wet/dry weight ratio,and reduced the pathological damage of lungs.The degree of vascular congestion,edema and inflammatory cell infiltration in lung tissue of the sepsis group increased with time,and the degree of lesions in the CVF group was milder than that in the sepsis group.The TNF-αlevel in lung tissue of septic rats was significantly down-regulated by CVF treatment,and the TNF-αlevels in the CVF group during the 8-24 h period ranged from[8 h:(1.47±0.14)ng/ml]to[24 h:(1.14±0.03)ng/ml],which was closer to that in sham operation group.Meanwhile,the IL-10level decreased from(91.3±5.5)ng/L to(39.8±13.4)ng/L during 8-24 h,which was higher than other groups.Conclusion:CVF can play a protective role against injury by down-regulating TNF-αand up-regulating IL-10 pathways,which can serve to alleviate focal lung injury and pulmonary edema from sepsis.

Carrimycin ameliorates lipopolysaccharide and cecal ligation and puncture-induced sepsis in mice

Carrimycin(CA),sanctioned by China’s National Medical Products Administration(NMPA)in 2019 for treating acute bronchitis and sinusitis,has recently been observed to exhibit multifaceted biological activities,encompassing anti-inflammatory,antiviral,and anti-tumor properties.Despite these applications,its efficacy in sepsis treatment remains unexplored.This study introduces a novel function of CA,demonstrating its capacity to mitigate sepsis induced by lipopolysaccharide(LPS)and cecal ligation and puncture(CLP)in mice models.Our research employed in vitro assays,real-time quantitative polymerase chain reaction(RT-qPCR),and RNA-seq analysis to establish that CA significantly reduces the levels of pro-inflammatory cytokines,namely tumor necrosis factor-alpha(TNF-α),interleukin 1 beta(IL-1β),and interleukin 6(IL-6),in response to LPS stimulation.Additionally,Western blotting and immunofluorescence assays revealed that CA impedes Nuclear Factor Kappa B(NF-κB)activation in LPS-stimulated RAW264.7 cells.Complementing these findings,in vivo experiments demonstrated that CA effectively alleviates LPS-and CLP-triggered organ inflammation in C57BL/6 mice.Further insights were gained through 16S sequencing,highlighting CA’s pivotal role in enhancing gut microbiota diversity and modulating metabolic pathways,particularly by augmenting the production of short-chain fatty acids in mice subjected to CLP.Notably,a comparative analysis revealed that CA’s anti-inflammatory efficacy surpasses that of equivalent doses of aspirin(ASP)and TIENAM.Collectively,these findings suggest that CA exhibits significant therapeutic potential in sepsis treatment.This discovery provides a foundational theoretical basis for the clinical application of CA in sepsis management.

Sodium tanshinone IIA sulfonate attenuates cardiac dysfunction and improves survival of rats with cecal ligation and puncture-induced sepsis

Cardiac dysfunction, a common consequence of sepsis, is the major contribution to morbidity and mortality in patients. Sodium tanshinone IIA sulfonate(STS) is a water-soluble derivative of Tanshinone IIA(TA), a main active component of Salvia miltiorrhiza Bunge, which has been widely used in China for the treatment of cardiovascular and cerebral system diseases. In the present study, the effect of STS on sepsis-induced cardiac dysfunction was investigated and its effect on survival rate of rats with sepsis was also evaluated. STS treatment could significantly decrease the serum levels of C-reactive protein(CRP), procalcitonin(PCT), cardiac troponin Ⅰ(cTn-Ⅰ), cardiac troponin T(cTn-T), and brain natriuretic peptide(BNP) in cecal ligation and puncture(CLP)-induced) septic rats and improve left ventricular function, particularly at 48 and 72 h after CLP. As the pathogenesis of septic myocardial dysfunction is attributable to dysregulated systemic inflammatory responses, several key cytokines, including tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), interleukin-6(IL-6), interleukin-10(IL-10) and high mobility group protein B1(HMGB1), were detected to reveal the possible mechanism of attenuation of septic myocardial dysfunction after being treated by STS. Our study showed that STS, especially at a high dose(15 mg×kg–1), could efficiently suppress inflammatory responses in myocardium and reduce myocardial necrosis through markedly reducing production of myocardial TNF-α, IL-6 and HMGB1. STS significantly improved the 18-day survival rate of rats with sepsis from 0% to 30%(P < 0.05). Therefore, STS could suppress inflammatory responses and improve left ventricular function in rats with sepsis, suggesting that it may be developed for the treatment of sepsis.

Changes of the immunological barrier of intestina mucosa in rats with sepsis

BACKGROUND： Sepsis has become the greatest threat to in-patients, with a mortality of over 25%.The dysfunction of gut barrier, especially the immunological barrier, plays an important role in the development of sepsis. This dysfunction occurs after surgery, but the magnitude of change does not differentiate patients with sepsis from those without sepsis. Increased intestinal permeability before surgery is of no value in predicating sepsis. The present study aimed to observe the changes of intestinal mucosal immunologic barrier in rat models of sepsis induced by cecal ligation and puncture.METHODS： Sixty Sprague-Dawley rats were randomly divided into a sepsis group （n=45） and a control group （n=15）. The rats in the sepsis group were subjected to cecal ligation and puncture （CLP）, whereas the rats in the control group underwent a sham operation. The ileac mucosa and segments were harvested 3, 6 and 12 hours after CLP, and blood samples were collected. Pathological changes, protein levels of defensin-5 （RD-5） and trefoil factor-3 （TFF3） mRNA, and lymphocytes apoptosis in the intestinal mucosa were determined. In an additional experiment, the gut-origin bacterial DNA in blood was detected.RESULTS： The intestinal mucosa showed marked injury with loss of ileal villi, desquamation of epithelium, detachment of lamina propria, hemorrhage and ulceration in the sepsis group. The expression of TFF3 mRNA and level of RD-5 protein were decreased and the apoptosis of mucosal lymphocyte increased （P〈0.05） in the sepsis group compared with the control group. Significant differences were observed in RD-5 and TFF3 mRNA 3 hours after CLP and they were progressively increased 6 and 12 hours after CLP in the sepsis group compared with the control group （P〈0.05, RD-5 F=11.76, TFF3 F=16.86 and apoptosis F=122.52）. In addition, the gut-origin bacterial DNA detected in plasma was positive in the sepsis group.CONCLUSION： The immunological function of the intestinal mucosa was impaired in septic rats and further deteriorated in the course of sepsis.

Accelerated Autophagy of Cecal Ligation and Puncture-Induced Myocardial Dysfunction and Its Correlation with Mammalian Target of Rapamycin Pathway in Rats

Background：Recent studies have indicated that autophagy is involved in sepsis-induced myocardial dysfunction.This study aimed to investigate the change of autophagy in cecal ligation and puncture （CLP）-induced myocardium dysfunction and its relationship with mammalian target of rapamycin （mTOR） pathway.Methods：Totally,12 rats were randomly divided into CLP group or sham-operated （SHAM） group.Cardiac tissues were harvested 18 h after CLP or sham operation.Pathology was detected by hematoxylin and eosin staining,cardiac functions by echocardiography,distribution ofmicrotubule-associated protein light chain 3 type Ⅱ （LC3II） by immunohistochemical staining,and autophagic vacuoles by transmission electron microscopy.Moreover,phosphorylation of mTOR （p-mTOR）,phosphorylation of S6 kinase-1 （PS6K1）,and LC3II and p62 expression were measured by western blotting.Pearson＇s correlation coefficient was used to analyze the correlation of two parameters.Results：The results by pathology and echocardiography revealed that there was obvious myocardial injury in CLP rats （left ventricle ejection fraction：SHAM 0.76 ± 0.06 vs.CLP 0.59 ± 0.l l,P 〈 0.01;fractional shortening：SHAM 0.51 ± 0.09 vs.CLP 0.37 ± 0.06,P 〈 0.05）.We also found that the autophagy process was elevated by CLE the ratio of LC3II/LC3I was increased （P 〈 0.05） while the expression of p62 was decreased （P 〈 0.05） in the CLP rats,and there were also more autophagosomes and autolysosomes in the CLP rats.Furthermore,the mTOR pathway in CLP myocardium was inhibited when compared with the sham-operated rats;p-mTOR （P 〈 0.01） and PS6K 1 （P 〈 0.05） were both significantly suppressed following CLP challenge.Interestingly,we found that the mTOR pathway was closely correlated with the autophagy processes.In our study,while p-mTOR in the myocardium was significantly correlated with p62 （r=0.66,P =0.02）,PS6K1 was significantly positively correlated with p62 （r =0.70,P =0.01） and negatively correlated with LC31I （r =-0.71,P =0.01）.Conclusions：The autophagy process in the myocardium was accelerated in CLP rats,which was closely correlated with the inhibition of the mTOR pathway.

Astragaloside IV Attenuates Polymicrobial Sepsis-Induced Cardiac Dysfunction in Rats via IKK/NF-κB Pathway

Objective To evaluate the protective effects of Astragaloside IV(AST)in a rat model of myocardial injury induced by cecal ligation and puncture(CLP).Methods The model of sepsis-induced cardiac dysfunction was induced by CLP.Using a random number table,50 specific pathogen free grade of Sprague Dawley rats were randomized into 5 groups:the sham group(sham),the model group(CLP,18 h/72 h)and AST group(18 h/72 h).Except the sham group,the rats in other groups received CLP surgery to induce sepsis.CLP groups received intragastric administration with normal saline after CLP.AST groups received intragastric administration with AST solution(40 mg/kg)once a day.The levels of inflammatory mediators and oxidative stress markers in the serum of the septic rats were determined via enzyme-linked immunosorbent assay(ELISA)at different time point,such as interleukin 6(IL-6),IL-10,high mobility group box-1 protein B1(HMGB-1),superoxide dismutase(SOD),and malondialdehyde(MDA).Cardiac function was determined by echocardiography.Moreover,changes in myocardial pathology were evaluated using hematoxylin and eosin staining.The levels of lactate dehydrogenase(LDH)and creatine kinase-MB(CK-MB)were analysed to determine the status of CLP-induced myocardium.In addition,the apotosis of myocardial cells was analysed by terminal-deoxynucleoitidyl transferase mediated nick end labeling(TUNEL).The protein levels of B-cell lymphoma-2(Bcl-2),Bcl-2-associated X(Bax),IκB kinaseα(IKKα),nuclear factor kappa B p65(NF-κB p65)were detected by Western blot analysis.Moreover,survival rate was investigated.Results AST improved the survival rate of CLP-induced rats by up to 33.3%(P<0.05).The cardioprotective effect of AST was observed by increased ejection fraction,fractional shortening and left ventricular internal diameter in diastole respectively(P<0.01 or P<0.05).Subsequently,AST attenuated CLP-induced myocardial apoptosis and the ratio of Bcl-2/Bax in the myocardium,as well as the histological alterations of myocardium(P<0.01 or P<0.05);the generation of inflammatory cytokines(IL-6,IL-10,HMGB-1)and oxidative stress markers(SOD,MDA)in the serum was significantly alleviated(P<0.01 or P<0.05).On the other hand,AST markedly suppressed CLP-induced accumulation of IKK-αand NF-κB p65 subunit phosphorylation(P<0.01 or P<0.05).Conclusions AST plays a significant protective role in sepsis-induced cardiac dysfunction and survival outcome.The possible mechanism of cardioprotection is dependent on the activation of the IKK/NF-κB pathway in cardiomyocytes.