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Objective:To investigate the effect of stress-induced protein Sestrin2 (SESN2) on necroptosis of mouse dendritic cell (DC) induced by lipopolysaccharide (LPS) combined with zVAD, a panaspartate-specific cysteine protease (caspase) inhibitor.Methods:The DC2.4 cell line derived from the bone marrow of mouse in the 3rd to 10th generations was cultured. The cells were stimulated with LPS for 0 hour, 6 hours, 12 hours, and 24 hours, and grouped according to the stimulation time points. Western blotting was performed to determine the protein expression of SESN2 in each group. Overexpression empty lentivirus (NC), SESN2 gene overexpression RNA sequence lentivirus (SESN2 LV-RNA), small interfering empty lentivirus (NS), and SESN2 gene small interfering RNA sequence lentivirus (SESN2 siRNA) were transfected into DC2.4 cells. After 72 hours of transfection, cell fluorescence expression was observed under the inverted fluorescence microscope. Cells in each transfection group were stimulated with LPS for 24 hours. The blank control groups were set up and cultured with phosphate buffered saline (PBS) for 24 hours. Western blotting was performed to measure SESN2 protein expression. In the same groups as above, cells were stimulated with LPS+zVAD for 24 hours. The blank control groups were set up and cultured with PBS for 24 hours. Western blotting was used to determine the expression of mixed lineage kinase domain-like protein (MLKL) and phosphorylated-MLKL (p-MLKL). The p-MLKL levels and the number of positive cells were observed using laser scanning confocal microscopy. The necroptotic cell ratios were assessed by both flow cytometry and Hoechst staining.Results:Compared to the LPS 0 hour group, the expression of SESN2 in the LPS 24 hours group showed a significant increase. Therefore, 24 hours was chosen as the subsequent stimulation time point. After successful lentivirus transduction and 24 hours of cultivation, the MLKL phosphorylation level in the SESN2 siRNA+LPS+zVAD group was significantly higher than that in the NS+LPS+zVAD group. The MLKL phosphorylation in the SESN2 LV-RNA+LPS+zVAD group was significantly lower than that in the NC+LPS+zVAD group. The MLKL phosphorylation levels in both the NS+LPS+zVAD group and the NC+LPS+zVAD group were obviously higher than those in the NS+PBS group and the NC+PBS group, respectively. Laser scanning confocal microscopy showed that the trends in quantity and fluorescence intensity of p-MLKL protein expressions were consistent with the above results. The results from flow cytometry analysis and Hoechst staining showed that the rates of cell necrotic apoptosis in SESN2 siRNA+LPS+zVAD group were significantly higher than those in NS+LPS+zVAD group [flow cytometry analysis: (30.800±1.153)% vs. (20.800±1.114)%, Hoechst staining: (75.267±0.451)% vs. (46.267±3.371)%, both P < 0.05], indicating that knocking down SESN2 further exacerbated the occurrence of necroptosis. The necrotic apoptosis rates in SESN2 LV-RNA+LPS+zVAD group were significantly lower than those in NC+LPS+zVAD group [flow cytometry analysis: (7.160±0.669)% vs. (19.240±2.322)%, Hoechst staining: (32.433±3.113)% vs. (48.567±4.128)%, both P < 0.05], indicating that overexpressing SESN2 reversed such response and markedly reduced the proportion of necroptotic cells compared to the corresponding empty vector group. Conclusion:SESN2 exhibits an inhibitory effect on necroptosis of DC in sepsis. Targeted SESN2 expression may regulate the process of DC-mediated immune response in sepsis.
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Objective:To explore the technique and clinical effects of free medial plantar flap on reconstruction of the severe defect of thumb caused by electric burn.Methods:Surgical techniques and clinical effects were explored in reconstruction with free medial plantar flap for treatment of severe electric burns of thumbs. From July 2016 to July 2021, 18 patients suffered from severe electric burns of thumbs were admitted in the Department of Burn, Zhengzhou First People's Hospital. All the wounds were the entrance of electric burns. After thorough debridement, the arteries, nerves, tendons, phalanges and interphalangeal joints were exposed to various degrees. Damaged digital proper palmar arteries were ligated and defected proper palmar digital nerves were marked and further anastomosed with the nerves carried by the flap. Palmaris longus tendon grafts were employed to reconstruct the defects of flexor pollicis longus tendon. Wounds were closed by transfer of free medial plantar flaps, and the flap donor sites were closed by inguinal skin grafts. Survival of the flap was observed 1 week after surgery, and the survival of the skin graft in the foot donor site 12 days after surgery. Outpatient follow-up including observation of the appearance and texture of the flap, evaluation of sensory function, thumb alignment and finger flexion according to the Evaluation Trial Standards of Upper Limb Partial Functional of Hand Surgery of Chinese Medical Association. Evaluate the scar hyperplasia in the foot donor site and the standing and walking functions of the donor foot.Results:All flaps survived,at 1 week after surgery. On the 12th day after surgery, all 16 foot flap survived, and 2 patients had local necrosis, and the necrosis healed completely after dressing change for 10 days, the wound healed completely. Among them, 3 patients without tendon transfer experienced a rupture of the flexor pollicis longus tendon at 2 months after surgery, and underwent another palmaris longus tendon transfer. After the surgery, functional exercise was performed with the palm and flexor fingers. After 6-12 months of follow-up, the blood supply, appearance, and texture of the flap were good and similar to that of the palmar skin of the thumb, with varying degrees of recovery in sensation. The TPD was 6-11 mm, and the thumb was restored to varying degrees. According to the Evaluation Trial Standards of Upper Limb Partial Functional of Hand Surgery of Chinese Medical Association, 13 cases in excellent and 5 cases in good. Mild scar hyperplasia remains in the flap site of donor feet, which does not affect the standing and walking functions of the donor foot.Conclusion:The texture of medial plantar skin is similar to that of palmar skin, with good wear resistance and good sensation. Furthermore, it causes a little damage to the donor site and without obvious complication. The medial plantar flap is ideal for reconstruction of a severe wound caused by electric burn in thumb.
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Objective:To investigate the role and significance of NUFIP-1-mediated ribophagy in apoptosis of dendritic cells (DCs) stimulated by lipopolysaccharide (LPS).Methods:Cultured mouse dendritic cell line DC2.4 were divided into the blank control group and LPS stimulation groups for 6, 12, 24, 48 and 72 h ( n=5). LPS subgroups were consistently cultured with 1 μg/mL LPS for the corresponding incubation time. Western blot was adopted to detect the expression levels of NUFIP-1 and autophagy-related proteins p62 and LC3B across groups. Laser scanning confocal microscopy (LSCM) was applied to detect the expression and cellular localization of NUFIP-1, with its co-localization with Lyso-tracker and LC3B, respectively. The silencing blank vector NS and silencing virus vector NUFIP-1 siRNA were transferred into DC2.4 ( n=3) and stimulated with 1 μg/mL LPS for 24 h. The apoptosis of DC2.4 was measured by flow cytometry analysis. The expression levels of apoptosis-related proteins were determined using Western blot, including cleaved caspase-3 and Bcl-2. One-way analysis of variance (ANOVA) was applied for comparison among multiple groups, and LSD-t method was used for subsequent pairwise comparison. A P<0.05 was considered statistically significant. Results:The results of Western blot showed that expression level of NUFIP-1 in DC2.4 revealed a trend of first increasing and subsequent decreasing upon LPS stimulation for different times (6, 12, 24, 48 and 72 h), and the expression level of NUFIP-1 in the LPS 24 h group was significantly higher than that in the blank control group [blank control group: (0.6786 ± 0.0820); LPS 24 h group: (1.4830 ± 0.1170); P<0.01]. Meanwhile, p62 expression in the LPS 24 h group was significantly lower than that in the blank control group [blank control group: (0.9087 ± 0.1235); LPS 24 h group: (0.3113 ± 0.5571); P<0.01]. Moreover, the conversion from LC3B-I to LC3B-II in the LPS 24 h group was significantly higher than that in the blank control group [blank control group: (0.5542 ± 0.1248); LPS 24 h group: (2.5310 ± 0.3119); P<0.01]. LSCM indicated that NUFIP-1 was predominantly located in the nucleus and perinuclear area in DC2.4. The fluorescence intensity of NUFIP-1 increased in a time-dependent manner from 6 h to 24 h after LPS stimulation, whereas a significant reduction could be observed at 48 h and 72 h after LPS stimulation. Meanwhile, the co-localization of NUFIP-1 with Lyso-tracker and LC3B was substantially reinforced in comparison with the blank control group. Transfection of NUFIP-1 siRNA through lentivirus transfection technology significantly down-regulated the expression level of NUFIP-1 in DC2.4, with statistical differences compared with the blank control group and empty vector group [blank control group: (0.6627 ± 0.1707); empty vector group: (0.6966 ± 0.1107); siRNA group: (0.1428 ± 0.0296); P<0.05]. Flow cytometry analysis revealed that the apoptotic rate of LPS-stimulated DC2.4 was significantly higher in the NUFIP-1 siRNA transfection group than that in the blank control group and empty vector group [blank control LPS 24 h group: (47.91% ± 1.006%); empty vector LPS 24 h group: (70.26% ± 1.011%); siRNA LPS 24 h group: (80.23% ± 2.094); P<0.01]. Western blot analysis of apoptosis-related protein further confirmed that the expression level of cleaved caspase-3 was significantly elevated in the NUFIP-1 siRNA transfection group compared to those of the blank control group and empty vector group under LPS challenge [blank control LPS 24 h group: (0.4748 ± 0.0876); empty vector LPS 24 h group: (0.2849 ± 0.0418); siRNA LPS 24 h group: (0.9733 ± 0.0525); P<0.01]. Likewise, expression of Bcl-2, an anti-apoptotic protein was significantly down-regulated in the siRNA LPS 24 h group [blank control LPS 24 h group: (0.7810 ± 0.0490); empty vector LPS 24 h group: (0.8292 ± 0.0729); siRNA LPS 24 h group: (0.3957 ± 0.0838); P<0.05]. Conclusions:NUFIP-1-mediated ribophagy is significantly activated in DC2.4 upon LPS stimulation, exerting an underlying protective effect on apoptosis.
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Sepsis is caused by various pathogens and toxic factors, which can lead to multiple organ dysfunction. The underlying mechanism of sepsis appears to be complex, involving epigenetic reprogramming, metabolic failure, immune dysfunction, neuroendocrine system disorders, coagulation abnormalities, tissue or organ failure, and many other scientific issues. With our deep understanding of the host reaction and development of sepsis, it is of great significance to explore predicative markers and therapeutic targets according to the atypical characteristics of sepsis, thereby contributing to the reduction of morbidity and mortality of sepsis.
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Objective:To explore the effects of Xuebijing injection and its component hydroxysafflor yellow A on coagulation and survival rates of septic rats.Methods:① Assessment of coagulation: 144 male Sprague-Dawley (SD) rats were divided into four groups by random number table: sham group, cecal ligation and puncture (CLP) induced sepsis model group (CLP group), CLP+Xuebijing group, and CLP+hydroxysafflor yellow A group, with 36 rats in each group. CLP was used for reproducing septic models. The cecum of the rats in the sham group was exposed by laparotomy and then returned to the abdominal cavity without CLP, while the other steps were the same as those in the CLP group. Rats in the CLP+Xuebijing group and CLP+hydroxysafflor yellow A group were injected with Xuebijing (4 mL/kg, twice a day) or hydroxysafflor yellow A solution (0.378 g/L, 298 μg each time, twice a day) through caudal vein after operation. Levels of prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen (Fib), and D-dimer in peripheral blood were measured by automatic coagulation analyzer at 6, 12, 24 hours after operation. The enzyme linked immunosorbent assay (ELISA) was applied to determine levels of tissue factor (TF), tissue factor pathway inhibitor (TFPI), and soluble thrombomodulin (sTM) in peripheral blood. ② Analysis of survival rates: 120 rats were divided into four groups by random number table (the same groups with those in the section of assessment of coagulation), with 30 rats in each group. The Kaplan-Meier survival curve was plotted, and the cumulative survival rates were observed and recorded for 7 days after CLP surgery.Results:① Results of coagulation assessment: compared with the sham group, septic rats in the CLP group showed significant dysfunction in coagulation early, as evidenced by prolonged PT at 6 hours after CLP (s: 8.9±0.2 vs. 8.4±0.4, P < 0.01), and significantly increased levels of Fib, D-dimer, TFPI and sTM [Fib (g/L): 2.8±0.3 vs. 2.3±0.1, D-dimer (ng/L): 1.8±0.2 vs. 1.5±0.1, TFPI (ng/L): 131.1±10.9 vs. 102.8±10.5, sTM (μg/L): 27.2±1.2 vs. 19.8±2.9, all P < 0.01]. The coagulation dysfunction became more and more serious at 12 hours after operation, and further deteriorated with time. The use of both Xuebijing and hydroxysafflor yellow A revealed significant improvement in coagulation of septic rats at 6 hours, as shown by shortened PT (s: 8.3±0.2, 8.3±0.1 vs. 8.9±0.2, both P < 0.01), and decreased Fib, D-dimer, TFPI and sTM as compared with those in the CLP group [Fib (g/L): 2.3±0.1, 2.3±0.2 vs. 2.8±0.3; D-dimer (ng/L): 1.5±0.1, 1.5±0.2 vs. 1.8±0.2; TFPI (ng/L): 109.5±10.2, 91.5±5.0 vs. 131.1±10.9; sTM (μg/L): 22.3±1.5, 21.1±1.8 vs. 27.2±1.2; all P < 0.01]. However, there was no significant difference in coagulation function between the two intervention groups. ② Results of survival rates analysis: the rats in the sham group all survived 7 days after operation. The 7-day cumulative survival rate of the CLP group was only 36.67% (11/30). Compared with the CLP group, the cumulative survival rates were significantly increased in rats of the CLP+Xuebijing group and CLP+hydroxysafflor yellow A group [66.67% (20/30), 66.67% (20/30) vs. 36.67% (11/30), both P < 0.05], but no significant difference was found between the CLP+Xuebijing group and CLP+hydroxysafflor yellow A group. Conclusion:Both Xuebijing and its component hydroxysafflor yellow A appear to be capable of alleviating coagulation disorders and improving survival rates of septic rats effectively, and the effects show no significant difference between them.
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With rapid progress and dangerous prognosis, traumatic brain injury (TBI) brings great difficulties in the clinical treatment, which becomes a prominent problem for the modern emergency and critical care medicine. In addition to the necessary surgical intervention under special circumstances, there are new understandings about the clinical management measures, noninvasive and invasive monitoring mode of TBI in recent years. This review provides a summary of the monitoring and treatment on the TBI, with our deep understanding of regulatory mechanism underlying TBI, precise modulation might be of clinical significance in preventing secondary damage of tissues and organs, which would be associated with decreases in the disability and mortality of critically ill patients.
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Objective:To investigate the effect of interleukin (IL)-37 on the immune function of regulatory T cells (Treg) in sepsis.Methods:TTregs were isolated and purified from the spleen of C57BL/6J mice and cultured in vitro. The cells were divided into the control group, lipopolysaccharide (LPS) group, IL-37 group, LPS+IL-37 group, LPS+3-Methyladenine (3-MA) group, LPS+3-MA+IL-37 group, LPS+Rapamaycin group, and LPS+Rapamaycin+IL-37 group. Culture supernatants and cells were collected, respectively, after cell culture for 24, 48, and 72 h. The secretion of IL-10 and TGF-β by Tregs was detected by ELISA, expressions of forkhead wing-link transcription factor (Foxp3) and cytotoxic T lymphocytes antigen 4 (CTLA-4) were measured by flow cytometry. Formation and number of autophagosomes were observed by transmission electron microscope. Western blot was used to determine expressions of autophagy associated proteins, including LC3I/II and Beclin1. Cecal ligation and puncture (CLP) was used to construct septic mice model, and the differences in survival rates between the groups were recorded and compared.Results:IL-37 was given to Tregs at 24, 48, and 72 h after LPS stimulation. The function of Treg was significantly enhanced after 72 h of synergistically stimulation by both LPS and IL-37. After stimulation with LPS and IL-37, the formation of autophagosomes in Tregs was obviously increased under observation of transmission electron microscopy. Pretreatment with autophagy agonist Rapamycin and autophagy inhibitor 3-MA was applied for altering the activity of cell autophagy. It was noticed that immune function of Treg was significantly decreased in the 3-MA group compared with the control group, while it was enhanced in the Rapamycin group. Secretion of TGF-β in the 3-MA group presented with significant reduction, which showed a marked increase in the Rapamycin group. However, no significant differences were found in IL-10 levels among various groups. Administration of IL-37 improved the survival rates of septic mice, which was much more efficient by treatment prior to the onset of sepsis.Conclusions:IL-37 appears to be capable of augmenting immune function of Tregs in an autophagy-dependent pathway, which might contribute to maintaining homeostasis of immune response in the setting of sepsis, and further improves the survival and prognosis of septic mice.
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Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Further development of sepsis usually leads to septic shock or even death. Many previous studies have focused on the abnormal reactions of monocytes/macrophages, neutrophils, complement system, or cytokine inflammation in sepsis. Many evidences in recent years suggest that dendritic cells, as the most powerful antigen-presenting cells in innate immune system of body, play important role during the process of immune disorders of sepsis. In this article, I review the main classification, immune function, monitoring method, regulatory pathways of dendritic cells and their clinical significance in immune disorders of sepsis, so as to find new strategies for immune regulation of sepsis.
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As the body′s largest organ, skin harbors a large amount of immune cells to regulate both innate and adaptive immune responses. Regulatory T cells (Tregs), as a subset of T lymphocytes with negative regulatory functions, play an important role in maintaining the immune homeostasis of different tissue. However, researches of skin Tregs are largely limited and uncompleted as compared with other tissue. In recent years, a comprehensive understanding is increasingly showing the specialized functions of Tregs in skin, including the orchestration of tissue wound healing, involvement in hair follicle recycling, and modulation of proper immune homeostasis. In this review, we outline the classification and characteristics of Tregs in skin, distribution, migration routes, immune effects, and relationship with wound healing, which aims to deepening our understanding towards the immunological effects of T lymphocytes subsets in skin and its regulatory pathways.
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The tumor necrosis factor-α-induced protein 8-like (TNFAIP8, TIPE) family is recently identified proteins consisting of four highly homologous mammalian proteins: TIPE, TIPE1, TIPE2, and TIPE3. Although the four members share similar molecular structure and function, involving effects in pathophysiological processes of inflammation, immunity, tumors, stroke, angiogenesis, and other diseases, they have individual characteristics. Many studies have shown that TIPE2 is an essential negative regulator of both innate and adaptive immunity. Up-regulation of TIPE2 expression can alleviate excessive inflammation during septic shock and maintain hemostasis of macrophages, neutrophils, dendritic cells, T cells, and B cells. In this review, we summarize the current literature for structure feature, immune function, and regulatory mechanism of TIPE2, together with its clinical significance in the pathogenesis of immune disorders of a wide array of human diseases. Understanding the basic biology of this new molecule might help us to seek novel strategies for the immunomodulation of human diseases.
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A multicenter blinded randomized controlled trial (RCT) was conducted in accordance with international clinical trial standards to evaluate the efficacy and safety of Xuebijing injection in the treatment of severe community-acquired pneumonia (SCAP) under strict quality control condition. This article aims to illustrate key contents of the design ideas and implementation process of the RCT of Xuebijing injection in the treatment of SCAP, including the selection of research objects, design, implementation, and insights, etc., share experience with researchers of the respiratory and critical care, and provide reference for future studies in critical care.
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Preclinical animal studies precede the majority of clinical trials. While the clinical definitions of sepsis and recommended treatments are regularly updated, a systematic review of preclinical models of sepsis has not been done and clear modeling guidelines are lacking. To address this deficit, a Wiggers-Bernard Conference on preclinical sepsis modeling was held in Vienna in May, 2017. The goal of the conference was to identify limitations of preclinical sepsis models and to propose a set of guidelines, defined as the "Minimum Quality Threshold in Pre-clinical Sepsis Studies" (MQTiPSS), to enhance translational value of these models. A total of 31 experts from 13 countries participated and were divided into six thematic Working Groups: Study Design, Humane modeling, Infection types, Organ failure/dysfunction, Fluid resuscitation, and Antimicrobial therapy endpoints. As basis for the MQTiPSS discussions, the participants conducted a literature review of the 260 most highly cited scientific articles on sepsis models (2003-2012). Overall, the participants reached consensus on 29 points; 20 at "recommendation" and nine at "consideration" strength. This Executive Summary provides a synopsis of the MQTiPSS consensus. We believe that these recommendations and considerations will serve to bring a level of standardization to preclinical models of sepsis and ultimately improve translation of preclinical findings. These guideline points are proposed as "best practices" for animal models of sepsis that should be implemented. To encourage its wide dissemination, this article is freely accessible on the Intensive Care Medicine Experimental and Infection journal websites. In order to encourage its wide dissemination, this article is freely accessible in Shock, Infection, and Intensive Care Medicine Experimental.
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Objective@#To understand the mortality and influencing factors on injecting drug users (IDUs) with HIV/AIDS, in Guizhou province, 1996-2015.@*Methods@#A retrospective cohort study was conducted on IDUs with HIV/AIDS that were reported through national comprehensive HIV/AIDS information system, in Guizhou province during 1996-2015. Cox proportional hazard regression model was used to analyze the influencing factors on the mortality of HIV/AIDS.@*Results@#A total of 3 958 cases of IDUs with HIV/AIDS were recruited in this study, with all-cause mortality rate of 44.01% (1 742/3 958) and total mortality rate of 7.80/100 person-years, respectively. The median survival time between diagnosis and death was 8.08 years. Mortality rate was 3.57/100 person-years in the group receiving antiretroviral therapy (ART). The mortality appeared to be 4.08/100 person-years in the group who were on methadone maintenance treatment (MMT). Data from the multiple regression analysis indicated that factors of gender, ethnicity, age when HIV/AIDS diagnosis was made, CD4+T lymphocyte (CD4) count at the first testing, ART and MMT were significantly associated with deaths among these people. The risk of death in females was 0.82 times (95%CI: 0.69-0.98) higher than that in males. The risk of deaths among the ethnic minority subjects was 1.39 times (95%CI: 1.21-1.60) higher than that of the Hans. The risk of death appeared to be 2.44 times higher (95%CI: 1.07-5.56) in the over-50-year of age group than in the <20 year-old group, when HIV/AIDS was diagnosed for the first time. The risk of death in CD4 ≥500/μl group in the first time was 0.27 times (95%CI: 0.22-0.32) more than CD4 <200/μl group in the firs time. The risk of death in cases who were treated with ART or MMT was 2.83 times (95%CI: 2.45-3.26) and 1.35 times (95%CI: 1.15-1.59) higher than those who did not receive any treatment, respectively.@*Conclusion@#Higher risks on death seemed to be related to the following factors: being male, older age at the time of diagnosis, lower CD4 at diagnosis, not on ART or MMT among the IDUs with HIV/AIDS in Guizhou province, between 1996-2015.
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As outlined in the International Guidelines for Management of Sepsis and Septic Shock: 2016, initial fluid resuscitation and administration of antibiotics are key steps in the early management of sepsis and septic shock. However, such clear guidelines do not exist for preclinical sepsis models. To address these shortcomings, the Wiggers-Bernard conference on preclinical sepsis models was held in Vienna in May 2017. The participants reviewed 260 of the most highly cited papers between 2003 and 2012 that used sepsis models. The review demonstrated that over 70% of experiments either did not use or failed to report resuscitation and/or antibiotic treatment. This information served as the basis to create a series of recommendations and considerations for preclinical sepsis models; this Part Ⅲ report details the recommendations for fluid resuscitation and antibiotic treatment that should be addressed in sepsis models. Similar to human sepsis, fluid resuscitation is recommended in the experimental setting unless part of the study. Iso-osmolar crystalloid solutions are preferred. The administration route and its timing should be adjusted to the specific requirements of the model with preference given to dynamic rather than static hemodynamic monitoring. Predefined endpoints for fluid resuscitation and avoidance of fluid overload should be considered. Preclinical sepsis studies display serious inconsistencies in the use of antimicrobial protocols. To remedy this, antimicrobials are recommended for preclinical studies, with choice and dose adjusted to the specific sepsis model and pathogen(s). Ideally, the administration of antimicrobials should closely mimic clinical practice, taking into account the drug's pharmacokinetic profile, alterations in absorption, distribution and clearance, and host factors such as age, weight, and comorbidities. These recommendations and considerations are proposed as "best practices" for animal models of sepsis that should be implemented.
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Preclinical animal studies are mandatory before new treatments can be tested in clinical trials. However, their use in developing new therapies for sepsis has been controversial because of limitations of the models and inconsistencies with the clinical conditions. In consideration of the revised definition for clinical sepsis and septic shock (Sepsis-3), a Wiggers-Bernard Conference was held in Vienna in May 2017 to propose standardized guidelines on preclinical sepsis modeling. The participants conducted a literature review of 260 most highly cited scientific articles on sepsis models published between 2003 and 2012. The review showed, for example, that mice were used in 79% and euthanasia criteria were defined in 9% of the studies. PartⅠof this report details the recommendations for study design and humane modeling endpoints that should be addressed in sepsis models. The first recommendation is that survival follow-up should reflect the clinical time course of the infectious agent used in the sepsis model. Furthermore, it is recommended that therapeutic interventions should be initiated after the septic insult replicating clinical care. To define an unbiased and reproducible association between a new treatment and outcome, a randomization and blinding of treatments as well as inclusion of all methodological details in scientific publications is essential. In all preclinical sepsis studies, the high standards of animal welfare must be implemented. Therefore, development and validation of specific criteria for monitoring pain and distress, and euthanasia of septic animals, as well as the use of analgesics are recommended. A set of four considerations is also proposed to enhance translation potential of sepsis models. Relevant biological variables and comorbidities should be included in the study design and sepsis modeling should be extended to mammalian species other than rodents. In addition, the need for source control (in case of a defined infection focus) should be considered. These recommendations and considerations are proposed as "best practices" for animal models of sepsis that should be implemented.
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Although the clinical definitions of sepsis and recommended treatments are regularly updated, a systematic review has not been done for preclinical models. To address this deficit, a Wiggers-Bernard Conference on preclinical sepsis modeling reviewed the 260 most highly cited papers between 2003 and 2012 using sepsis models to create a series of recommendations. This PartⅡreport provides recommendations for the types of infections and documentation of organ injury in preclinical sepsis models. Concerning the types of infections, the review showed that the cecal ligation and puncture model was used for 44% of the studies while 40% injected endotoxin. Recommendation #8 (numbered sequentially from PartⅠ): endotoxin injection should not be considered as a model of sepsis; live bacteria or fungal strains derived from clinical isolates are more appropriate. Recommendation #9: microorganisms should replicate those typically found in human sepsis. Sepsis-3 states that sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection, but the review of the papers showed limited attempts to document organ dysfunction. Recommendation #10: organ dysfunction definitions should be used in preclinical models. Recommendation #11:not all activities in an organ/system need to be abnormal to verify organ dysfunction. Recommendation #12: organ dysfunction should be measured in an objective manner using reproducible scoring systems. Recommendation #13: not all experiments must measure all parameters of organ dysfunction, but investigators should attempt to fully capture as much information as possible. These recommendations are proposed as "best practices" for animal models of sepsis.
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Although the clinical definitions of sepsis and recommended treatments are regularly updated, a systematic review has not been done for preclinical models. To address this deficit, a Wiggers-Bernard Conference on preclinical sepsis modeling reviewed the 260 most highly cited papers between 2003 and 2012 using sepsis models to create a series of recommendations. This PartⅡreport provides recommendations for the types of infections and documentation of organ injury in preclinical sepsis models. Concerning the types of infections, the review showed that the cecal ligation and puncture model was used for 44% of the studies while 40% injected endotoxin. Recommendation #8 (numbered sequentially from PartⅠ): endotoxin injection should not be considered as a model of sepsis; live bacteria or fungal strains derived from clinical isolates are more appropriate. Recommendation #9: microorganisms should replicate those typically found in human sepsis. Sepsis-3 states that sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection, but the review of the papers showed limited attempts to document organ dysfunction. Recommendation #10: organ dysfunction definitions should be used in preclinical models. Recommendation #11:not all activities in an organ/system need to be abnormal to verify organ dysfunction. Recommendation #12: organ dysfunction should be measured in an objective manner using reproducible scoring systems. Recommendation #13: not all experiments must measure all parameters of organ dysfunction, but investigators should attempt to fully capture as much information as possible. These recommendations are proposed as "best practices" for animal models of sepsis.
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Although the clinical definitions of sepsis and recommended treatments are regularly updated, a systematic review has not been done for preclinical models. To address this deficit, a Wiggers-Bernard Conference on preclinical sepsis modeling reviewed the 260 most highly cited papers between 2003 and 2012 using sepsis models to create a series of recommendations. This PartⅡreport provides recommendations for the types of infections and documentation of organ injury in preclinical sepsis models. Concerning the types of infections, the review showed that the cecal ligation and puncture model was used for 44% of the studies while 40% injected endotoxin. Recommendation #8 (numbered sequentially from PartⅠ): endotoxin injection should not be considered as a model of sepsis; live bacteria or fungal strains derived from clinical isolates are more appropriate. Recommendation #9: microorganisms should replicate those typically found in human sepsis. Sepsis-3 states that sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection, but the review of the papers showed limited attempts to document organ dysfunction. Recommendation #10: organ dysfunction definitions should be used in preclinical models. Recommendation #11: not all activities in an organ/system need to be abnormal to verify organ dysfunction. Recommendation #12: organ dysfunction should be measured in an objective manner using reproducible scoring systems. Recommendation #13: not all experiments must measure all parameters of organ dysfunction, but investigators should attempt to fully capture as much information as possible. These recommendations are proposed as "best practices" for animal models of sepsis.
ABSTRACT
Preclinical animal studies are mandatory before new treatments can be tested in clinical trials. However, their use in developing new therapies for sepsis has been controversial because of limitations of the models and inconsistencies with the clinical conditions. In consideration of the revised definition for clinical sepsis and septic shock (Sepsis-3), a Wiggers-Bernard Conference was held in Vienna in May 2017 to propose standardized guidelines on preclinical sepsis modeling. The participants conducted a literature review of 260 most highly cited scientific articles on sepsis models published between 2003 and 2012. The review showed, for example, that mice were used in 79% and euthanasia criteria were defined in 9% of the studies. PartⅠof this report details the recommendations for study design and humane modeling endpoints that should be addressed in sepsis models. The first recommendation is that survival follow-up should reflect the clinical time course of the infectious agent used in the sepsis model. Furthermore, it is recommended that therapeutic interventions should be initiated after the septic insult replicating clinical care. To define an unbiased and reproducible association between a new treatment and outcome, a randomization and blinding of treatments as well as inclusion of all methodological details in scientific publications is essential. In all preclinical sepsis studies, the high standards of animal welfare must be implemented. Therefore, development and validation of specific criteria for monitoring pain and distress, and euthanasia of septic animals, as well as the use of analgesics are recommended. A set of four considerations is also proposed to enhance translation potential of sepsis models. Relevant biological variables and comorbidities should be included in the study design and sepsis modeling should be extended to mammalian species other than rodents. In addition, the need for source control (in case of a defined infection focus) should be considered. These recommendations and considerations are proposed as "best practices" for animal models of sepsis that should be implemented.
ABSTRACT
As outlined in the International Guidelines for Management of Sepsis and Septic Shock: 2016, initial fluid resuscitation and administration of antibiotics are key steps in the early management of sepsis and septic shock. However, such clear guidelines do not exist for preclinical sepsis models. To address these shortcomings, the Wiggers-Bernard conference on preclinical sepsis models was held in Vienna in May 2017. The participants reviewed 260 of the most highly cited papers between 2003 and 2012 that used sepsis models. The review demonstrated that over 70% of experiments either did not use or failed to report resuscitation and/or antibiotic treatment. This information served as the basis to create a series of recommendations and considerations for preclinical sepsis models; this Part Ⅲ report details the recommendations for fluid resuscitation and antibiotic treatment that should be addressed in sepsis models. Similar to human sepsis, fluid resuscitation is recommended in the experimental setting unless part of the study. Iso-osmolar crystalloid solutions are preferred. The administration route and its timing should be adjusted to the specific requirements of the model with preference given to dynamic rather than static hemodynamic monitoring. Predefined endpoints for fluid resuscitation and avoidance of fluid overload should be considered. Preclinical sepsis studies display serious inconsistencies in the use of antimicrobial protocols. To remedy this, antimicrobials are recommended for preclinical studies, with choice and dose adjusted to the specific sepsis model and pathogen(s). Ideally, the administration of antimicrobials should closely mimic clinical practice, taking into account the drug's pharmacokinetic profile, alterations in absorption, distribution and clearance, and host factors such as age, weight, and comorbidities. These recommendations and considerations are proposed as "best practices" for animal models of sepsis that should be implemented.