Identifying Therapeutic Targets for Sepsis Research: A Characterization Study of the Inflammatory Players in the Cecal Ligation and Puncture Model

20(S)-ginsenoside Rg3 alleviates DSS-induced colitis by promoting ERK-dependent maturation of MDSCs into M2 macrophages

Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells with immunosuppressive functions that play various roles in tumors and inflammatory diseases. In colitis, MDSCs accumulate in the inflamed colon, where they mature into M2-polarized macrophages and modulate inflammatory responses. Ginsenosides, active components of ginseng, have been shown to display colitis-alleviating effects in mouse models. However, the detailed mechanisms underlying these effects are incompletely understood. This study explores the impact of ginsenosides on MDSC functions and differentiation, focusing on their potential to mitigate inflammatory symptoms in colitis. Among the 15 ginsenosides tested, Rg3(R) and Rg3(S) were found to promote the maturation of MDSCs into M2 macrophages at non-cytotoxic concentrations. This was confirmed by the increased expression of ARG1, an immunosuppressive marker. These effects were attributed to the activation of the ERK pathway, as confirmed by selective ERK inhibition. In a DSS-induced colitis mouse model, oral administration of Rg3(S) alleviated disease severity and increased MDSC differentiation into M2 macrophages in colon lamina propria, highlighting its therapeutic potential colitis.

Lymphopenia in sepsis: a narrative review

This narrative review provides an overview of the evolving significance of lymphopenia in sepsis, emphasizing its critical function in this complex and heterogeneous disease. We describe the causal relationship of lymphopenia with clinical outcomes, sustained immunosuppression, and its correlation with sepsis prediction markers and therapeutic targets. The primary mechanisms of septic lymphopenia are highlighted. In addition, the paper summarizes various attempts to treat lymphopenia and highlights the practical significance of promoting lymphocyte proliferation as the next research direction.

Effect of Anterograde Lavage via Temporary Loop Ileostoma on the Recovery of Bowel Function in Patients Receiving Stoma Closure: A Retrospective Cohort Study

BACKGROUND

The effect of anterograde lavage in patients with rectal cancer who underwent anterior resection and plan to receive stoma closure is unclear.

OBJECTIVE

This study aimed to investigate the effect of anterograde lavage on postoperative bowel function recovery in patients who underwent temporary loop ileostomy and stoma closure.

DESIGN

This was a hospital-based retrospective cohort study.

SETTINGS

This study was conducted at a tertiary referral center.

PATIENTS

All consecutive patients who underwent anterior resection for rectal cancer and were planning to receive stoma closure from March through December 2019 were included.

INTERVENTIONS

The enrolled patients were divided into 2 groups according to whether they received anterograde lavage before stoma closure.

MAIN OUTCOME MEASURES

Short-term functional outcomes, including time to first passing of flatus, first defecation time, and recovery time to first meal, were compared between the groups. Secondary outcomes included length of hospital stay, total cost of hospitalization, and postoperative complications.

RESULTS

A total of 222 eligible participants were included in the analysis, including 114 in the lavage group and 108 in the nonlavage group. No statistically significant differences were found in age, sex ratio, or distance between the anastomotic line and dentate line. In the lavage group, patients' time to first passing of flatus (38 vs 42 h; p = 0.006), first defecation time (42 vs 48 h; p < 0.001), recovery time to first meal (48 vs 55.5 h; p < 0.001), and length of hospital stay (5 vs 7 d; p < 0.001) were significantly shorter than those in the nonlavage group, and the total cost of hospitalization was significantly lower than that of the nonlavage group (25,000 vs 28,000 RMB; p < 0.001). No significant difference was found in the incidence of postoperative complications between the 2 groups (p = 0.067).

LIMITATIONS

This study is limited by its relatively small sample size and retrospective design with single-center participants.

CONCLUSIONS

Anterograde lavage before stoma closure is safe and noninvasive. For patients receiving anterior resection and planning to have stoma closure, this procedure can potentially help recover bowel function more rapidly. See Video Abstract at http://links.lww.com/DCR/C51.

EFECTO DEL LAVADO ANTERGRADO MEDIANTE ILEOSTOMA TEMPORAL EN ASA SOBRE LA RECUPERACIN DE LA FUNCIN INTESTINAL EN PACIENTES QUE RECIBEN CIERRE DE ESTOMA UN ESTUDIO DE COHORTE RETROSPECTIVO

ANTECEDENTES:No está claro el efecto del lavado anterógrado en pacientes con cáncer de recto con resección anterior que planean recibir el cierre del estoma.OBJETIVO:Investigar el efecto del lavado anterógrado en la recuperación de la función intestinal posoperatoria en pacientes que se sometieron a ileostomía en asa temporal y cierre de estoma.DISEÑO:Estudio de cohorte retrospectivo basado en el hospital.AJUSTES:Centro de referencia terciario.PACIENTES:Todos los pacientes que se sometieron a una resección anterior por cáncer de recto y que planeaban recibir el cierre del estoma desde marzo hasta diciembre de 2019.INTERVENCIONES:Los pacientes inscritos se dividieron en dos grupos según si recibieron lavado anterógrado antes del cierre del estoma.PRINCIPALES MEDIDAS DE RESULTADO:Los resultados funcionales a corto plazo, incluido el tiempo de la primera evacuación de flatos, tiempo de la primera defecación y tiempo de recuperación hasta la primera comida, se compararon entre los grupos. Resultados secundarios incluyeron duración de la estancia hospitalaria, costo total de la hospitalización y complicaciones posoperatorias.RESULTADOS:Se incluyeron en el análisis un total de 222 participantes elegibles, incluidos 114 en el grupo de lavado y 108 en el grupo de no lavado. No hubo diferencias estadísticamente significativas en la edad, la proporción de sexos o la distancia entre la línea de anastomosis y la línea dentada. En el grupo de lavado, el tiempo de la primera evacuación de flatos de los pacientes (38 vs 42 h; p = 0,006), el tiempo de la primera defecación (42 vs 48 h; p < 0,001), el tiempo de recuperación hasta la primera comida (48 vs 55,5 h; p < 0,001) y la duración de la estancia hospitalaria (5 vs 7 días; p < 0,001) fueron significativamente más cortos que los del grupo de no lavado, y el costo total de la hospitalización fue significativamente menor que el del grupo de no lavado (25000 vs 28000 RMB; p < 0,001). No hubo diferencia significativa en la incidencia de complicaciones postoperatorias entre los dos grupos (p = 0,067).LIMITACIONES:Este estudio está limitado por su tamaño de muestra relativamente pequeño y su diseño retrospectivo con participantes de un solo centro.CONCLUSIONES:El lavado anterógrado antes del cierre del estoma es seguro y no invasivo. Para los pacientes que se someten a una resección anterior y planean cerrar el estoma, este procedimiento puede ayudar potencialmente a recuperar la función intestinal más rápidamente. Consulte Video Resumen en http://links.lww.com/DCR/C51. (Traducción-Dr. Francisco M. Abarca-Rendon).

Increased mortality and altered local immune response in secondary peritonitis after previous visceral operations in mice

Postoperative peritonitis is characterized by a more severe clinical course than other forms of secondary peritonitis. The pathophysiological mechanisms behind this phenomenon are incompletely understood. This study used an innovative model to investigate these mechanisms, combining the models of murine Colon Ascendens Stent Peritonitis (CASP) and Surgically induced Immune Dysfunction (SID). Moreover, the influence of the previously described anti-inflammatory reflex transmitted by the vagal nerve was characterized. SID alone, or 3 days before CASP were performed in female C57BL/6 N mice. Subdiaphragmatic vagotomy was performed six days before SID with following CASP. The immune status was assessed by FACS analysis and measurement of cytokines. Local intestinal inflammatory changes were characterized by immunohistochemistry. Mortality was increased in CASP animals previously subjected to SID. Subclinical bacteremia occurred after SID, and an immunosuppressive milieu occurred secondary to SID just before the induction of CASP. Previous SID modified the pattern of intestinal inflammation induced by CASP. Subdiaphragmatic vagotomy had no influence on sepsis mortality in our model of postoperative peritonitis. Our results indicate a surgery-induced inflammation of the small intestine and the peritoneal cavity with bacterial translocation, which led to immune dysfunction and consequently to a more severe peritonitis.

Use of Organ Dysfunction as a Primary Outcome Variable Following Cecal Ligation and Puncture: Recommendations for Future Studies

Outcomes variables for research on sepsis have centered on mortality and changes in the host immune response. However, a recent task force (Sepsis-3) revised the definition of sepsis to "life-threatening organ dysfunction caused by a dysregulated host response to infection." This new definition suggests that human studies should focus on organ dysfunction. The appropriate criteria for organ dysfunction in either human sepsis or animal models are, however, poorly delineated, limiting the potential for translation. Further, in many systems, the difference between "dysfunction" and "injury" may not be clear. In this review, we identify criteria for organ dysfunction and/or injury in human sepsis and in rodents subjected to cecal ligation and puncture (CLP), the most commonly used animal model of sepsis. We further examine instances where overlap between human sepsis and CLP is sufficient to identify translational endpoints. Additional verification may demonstrate that these endpoints are applicable to other animals and to other sepsis models, for example, pneumonia. We believe that the use of these proposed measures of organ dysfunction will facilitate mechanistic studies on the pathobiology of sepsis and enhance our ability to develop animal model platforms to evaluate therapeutic approaches to human sepsis.

The Effect of a Novel Serine Protease Inhibitor on Inflammation and Intestinal Permeability in a Murine Colitis Transfer Model

Background: A protease/antiprotease disbalance is observed in inflammatory bowel diseases (IBD). We therefore studied the effect of the novel serine protease inhibitor UAMC-00050 on intestinal inflammation and permeability in a chronic colitis T cell transfer mouse model to get further insight into the regulation of T cell-mediated immunopathology. Methods: Colitis was induced in severe combined immunodeficient (SCID) mice, by the adoptive transfer of CD4⁺CD25^-CD62L⁺ T cells. Animals were treated intraperitoneally (i.p.) 2x/day with vehicle or UAMC-00050 (5 mg/kg) from week 2 onwards. Colonic inflammation was assessed by clinical parameters, colonoscopy, macroscopy, microscopy, myeloperoxidase activity and cytokine expression levels. At week 4, 4 kDa FITC-dextran intestinal permeability was evaluated and T helper transcription factors, protease-activated receptors and junctional proteins were quantified by RT-qPCR. Results: Adoptive transfer of CD4⁺CD25^-CD62L⁺ T cells resulted in colonic inflammation and an altered intestinal permeability. The serine protease inhibitor UAMC-00050 ameliorated both the inflammatory parameters and the intestinal barrier function. Furthermore, a decrease in colonic mRNA expression of Tbet and PAR4 was observed in colitis mice after UAMC-00050 treatment. Conclusion: The beneficial effect of UAMC-00050 on inflammation was apparent via a reduction of Tbet, IFN-γ, TNF-α, IL-1β and IL-6. Based on these results, we hypothesize a pivotal effect of serine protease inhibition on the Th1 inflammatory profile potentially mediated via PAR4.

The Surviving Sepsis Campaign: Basic/Translational Science Research Priorities

Objectives:

Expound upon priorities for basic/translational science identified in a recent paper by a group of experts assigned by the Society of Critical Care Medicine and the European Society of Intensive Care Medicine.

Data Sources:

Original paper, search of the literature.

Study Selection:

By several members of the original task force with specific expertise in basic/translational science.

Data Extraction:

None.

Data Synthesis:

None.

Conclusions:

In the first of a series of follow-up reports to the original paper, several members of the original task force with specific expertise provided a more in-depth analysis of the five identified priorities directly related to basic/translational science. This analysis expounds on what is known about the question and what was identified as priorities for ongoing research. It is hoped that this analysis will aid the development of future research initiatives.

Potential Targets to Mitigate Trauma- or Sepsis-Induced Immune Suppression

In sepsis and trauma, pathogens and injured tissue provoke a systemic inflammatory reaction which can lead to overwhelming inflammation. Concurrent with the innate hyperinflammatory response is adaptive immune suppression that can become chronic. A current key issue today is that patients who undergo intensive medical care after sepsis or trauma have a high mortality rate after being discharged. This high mortality is thought to be associated with persistent immunosuppression. Knowledge about the pathophysiology leading to this state remains fragmented. Immunosuppressive cytokines play an essential role in mediating and upholding immunosuppression in these patients. Specifically, the cytokines Interleukin-10 (IL-10), Transforming Growth Factor-β (TGF-β) and Thymic stromal lymphopoietin (TSLP) are reported to have potent immunosuppressive capacities. Here, we review their ability to suppress inflammation, their dynamics in sepsis and trauma and what drives the pathologic release of these cytokines. They do exert paradoxical effects under certain conditions, which makes it necessary to evaluate their functions in the context of dynamic changes post-sepsis and trauma. Several drugs modulating their functions are currently in clinical trials in the treatment of other pathologies. We provide an overview of the current literature on the effects of IL-10, TGF-β and TSLP in sepsis and trauma and suggest therapeutic approaches for their modulation.

Effect of Prolonged-Release Pirfenidone on Renal Function in Septic Acute Kidney Injury Patients: A Double-Blind Placebo-Controlled Clinical Trial

Background

There is no treatment for septic acute kidney injury (sAKI). The anti-inflammatory activity of prolonged-release pirfenidone (PR-PFD) could be beneficial in this clinical setting.

Methods

This study was a double-blind randomized clinical trial in sAKI patients with nephrology consultation at the Civil Hospital of Guadalajara, in addition to the usual treatment of AKI associated with sepsis; patients were randomized to receive either PR-PFD at 1,200 mg/day (group A) or 600 mg/day (group B) or a matched placebo for 7 consecutive days. The primary objective was the decrease in serum creatinine (sCr) and increase in urinary volume (UV); the secondary objectives were changes in serum electrolytes, acid-base status, and mortality.

Results

Between August 2016 and August 2017, 88 patients were randomized. The mean age was 54 (17 ± SD) years, and 47% were male. The main site of infection was the lung (39.8%), septic shock was present in 39.1% of the cases, and the mean SOFA score was 8.8 points. 28 patients received PFD 1,200 mg, 30 patients received PFD 600 mg, and 30 patients received placebo. During the study, sCr did not differ among the groups. The reversion rate of sCr, UV, and mortality was not different among the groups (p=0.70, p=0.47, and p=0.38, respectively). Mild adverse events were not different among the groups.

Conclusion

PR-PFD did not improve the clinical course of sAKI and seemed to be safe in terms of adverse events. This trial is registered with NCT02530359.

Lymphocyte Immunosuppression and Dysfunction Contributing to Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS)

ABSTRACT

Persistent Inflammation, Immune Suppression, and Catabolism Syndrome (PICS) is a disease state affecting patients who have a prolonged recovery after the acute phase of a large inflammatory insult. Trauma and sepsis are two pathologies after which such an insult evolves. In this review, we will focus on the key clinical determinants of PICS: Immunosuppression and cellular dysfunction. Currently, relevant immunosuppressive functions have been attributed to both innate and adaptive immune cells. However, there are significant gaps in our knowledge, as for trauma and sepsis the immunosuppressive functions of these cells have mostly been described in acute phase of inflammation so far, and their clinical relevance for the development of prolonged immunosuppression is mostly unknown. It is suggested that the initial immune imbalance determines the development of PCIS. Additionally, it remains unclear what distinguishes the onset of immune dysfunction in trauma and sepsis and how this drives immunosuppression in these cells. In this review, we will discuss how regulatory T cells (Tregs), innate lymphoid cells, natural killer T cells (NKT cells), TCR-a CD4- CD8- double-negative T cells (DN T cells), and B cells can contribute to the development of post-traumatic and septic immunosuppression. Altogether, we seek to fill a gap in the understanding of the contribution of lymphocyte immunosuppression and dysfunction to the development of chronic immune disbalance. Further, we will provide an overview of promising diagnostic and therapeutic interventions, whose potential to overcome the detrimental immunosuppression after trauma and sepsis is currently being tested.

The surviving sepsis campaign: basic/translational science research priorities

Objectives

Expound upon priorities for basic/translational science identified in a recent paper by a group of experts assigned by the Society of Critical Care Medicine and the European Society of Intensive Care Medicine.

Data sources

Original paper, search of the literature.

Study selection

This study is selected by several members of the original task force with specific expertise in basic/translational science. Data extraction and data synthesis are not available.

Conclusions

In the first of a series of follow-up reports to the original paper, several members of the original task force with specific expertise provided a more in-depth analysis of the five identified priorities directly related to basic/translational science. This analysis expounds on what is known about the question and what was identified as priorities for ongoing research. It is hoped that this analysis will aid the development of future research initiatives.

Effects of intestinal alkaline phosphatase on intestinal barrier function in a cecal ligation and puncture (CLP)-induced mouse model for sepsis

BACKGROUND

Sepsis is a severe pathological condition associated with systemic inflammation, intestinal inflammation, and gastrointestinal barrier dysfunction. Intestinal alkaline phosphatase (IAP) has been demonstrated to detoxify lipopolysaccharide, an important mediator in the pathophysiology of sepsis. We investigated the effect of treatment with IAP on intestinal permeability, intestinal inflammation, and bacterial translocation.

METHODS

OF-1 mice were divided into 4 groups (n = 12/group), undergoing either a sham or cecal ligation and puncture (CLP) procedure to induce sepsis. Mice received IAP or a vehicle intraperitoneally 5 minutes prior to the onset of the CLP or sham procedure, which was repeated every 12 hours for two consecutive days. After two days, in vivo intestinal permeability, intestinal inflammation, and bacterial translocation were determined.

KEY RESULTS

CLP-induced sepsis resulted in significantly more weight loss, worse clinical disease scores, bacterial translocation, and elevated inflammatory cytokines. Intestinal permeability was increased up to 5-fold (P < .001). IAP activity was significantly increased in septic animals. Treatment with IAP had no effect on clinical outcomes but reduced the increased permeability of the small intestine by 50% (P = .005). This reduction in permeability was accompanied by a modified gene expression of claudin-1 (P = .025), claudin-14 (P = .035), and interleukin 12 (P = .015). A discriminant analysis showed that treatment with IAP is linked to modified mRNA levels of several tight junction proteins and cytokines.

CONCLUSIONS AND INFERENCES

Treatment with IAP diminished CLP-induced intestinal barrier disruption, associated with modified expression of several cytokines and claudins. Nevertheless, this effect did not translate into better clinical outcomes in our experimental setup.