Extracellular CIRP induces CD4CD8αα intraepithelial lymphocyte cytotoxicity in sepsis.

BACKGROUND: In sepsis, intestinal barrier dysfunction is often caused by the uncontrolled death of intestinal epithelial cells (IECs). CD4CD8αα intraepithelial lymphocytes (IELs), a subtype of CD4+ T cells residing within the intestinal epithelium, exert cytotoxicity by producing granzyme B (GrB) and perforin (Prf). Extracellular cold-inducible RNA-binding protein (eCIRP) is a recently identified alarmin which stimulates TLR4 on immune cells to induce proinflammatory responses. Here, we hypothesized that eCIRP enhances CD4CD8αα IEL cytotoxicity and induces IEC death in sepsis. METHODS: We subjected wild-type (WT) and CIRP-/- mice to sepsis by cecal ligation and puncture (CLP) and collected the small intestines to isolate IELs. The expression of GrB and Prf in CD4CD8αα IELs was assessed by flow cytometry. IELs isolated from WT and TLR4-/- mice were challenged with recombinant mouse CIRP (eCIRP) and assessed the expression of GrB and Prf in CD4CD8αα by flow cytometry. Organoid-derived IECs were co-cultured with eCIRP-treated CD4CD8αα cells in the presence/absence of GrB and Prf inhibitors and assessed IEC death by flow cytometry. RESULTS: We found a significant increase in the expression of GrB and Prf in CD4CD8αα IELs of septic mice compared to sham mice. We found that GrB and Prf levels in CD4CD8αα IELs were increased in the small intestines of WT septic mice, while CD4CD8αα IELs of CIRP-/- mice did not show an increase in those cytotoxic granules after sepsis. We found that eCIRP upregulated GrB and Prf in CD4CD8αα IELs isolated from WT mice but not from TLR4-/- mice. Furthermore, we also revealed that eCIRP-treated CD4CD8αα cells induced organoid-derived IEC death, which was mitigated by GrB and Prf inhibitors. Finally, histological analysis of septic mice revealed that CIRP-/- mice were protected from tissue injury and cell death in the small intestines compared to WT mice. CONCLUSION: In sepsis, the cytotoxicity initiated by the eCIRP/TLR4 axis in CD4CD8αα IELs is associated with intestinal epithelial cell (IEC) death, which could lead to gut injury.

MicroRNA Profiles in Intestinal Epithelial Cells in a Mouse Model of Sepsis.

Sepsis is a systemic inflammatory disorder that leads to the dysfunction of multiple organs. In the intestine, the deregulation of the epithelial barrier contributes to the development of sepsis by triggering continuous exposure to harmful factors. However, sepsis-induced epigenetic changes in gene-regulation networks within intestinal epithelial cells (IECs) remain unexplored. In this study, we analyzed the expression profile of microRNAs (miRNAs) in IECs isolated from a mouse model of sepsis generated via cecal slurry injection. Among 239 miRNAs, 14 miRNAs were upregulated, and 9 miRNAs were downregulated in the IECs by sepsis. Upregulated miRNAs in IECs from septic mice, particularly miR-149-5p, miR-466q, miR-495, and miR-511-3p, were seen to exhibit complex and global effects on gene regulation networks. Interestingly, miR-511-3p has emerged as a diagnostic marker in this sepsis model due to its increase in blood in addition to IECs. As expected, mRNAs in the IECs were remarkably altered by sepsis; specifically, 2248 mRNAs were decreased, while 612 mRNAs were increased. This quantitative bias may be possibly derived, at least partly, from the direct effects of the sepsis-increased miRNAs on the comprehensive expression of mRNAs. Thus, current in silico data indicate that there are dynamic regulatory responses of miRNAs to sepsis in IECs. In addition, the miRNAs that were increased with sepsis had enriched downstream pathways including Wnt signaling, which is associated with wound healing, and FGF/FGFR signaling, which has been linked to chronic inflammation and fibrosis. These modifications in miRNA networks in IECs may lead to both pro- and anti-inflammatory effects in sepsis. The four miRNAs discovered above were shown to putatively target LOX, PTCH1, COL22A1, FOXO1, or HMGA2, via in silico analysis, which were associated with Wnt or inflammatory pathways and selected for further study. The expressions of these target genes were downregulated in sepsis IECs, possibly through posttranscriptional modifications of these miRNAs. Taken together, our study suggests that IECs display a distinctive miRNA profile which is capable of comprehensively and functionally reshaping the IEC-specific mRNA landscape in a sepsis model.

Possible Metastatic Stage-Dependent ILC2 Activation Induces Differential Functions of MDSCs through IL-13/IL-13Rα1 Signaling during the Progression of Breast Cancer Lung Metastasis.

Breast cancer is the most common cancer in women worldwide, and lung metastasis is one of the most frequent distant metastases. When breast cancer metastasizes to the lung, group 2 innate lymphoid cells (ILC2s) are thought to promote tumor growth via the activation of myeloid-derived suppressor cells (MDSCs), which are known to negatively regulate anticancer immune responses. However, it remains to be elucidated exactly how this ILC2-MDSC interaction is involved in tumor growth during metastases formation. Using a 4T1/LM4 breast cancer mouse model, we found that ILC2s were activated in both the micro- and macrometastatic regions, suggesting sustained activation throughout the metastatic cascades via IL-33/ST2 signaling. Consistent with IL-13 secretion from activated ILC2s, the frequencies of polymorphonuclear (PMN)- and monocytic (M)-MDSCs were also significantly elevated during the progression from micro- to macrometastatic cancer. However, the effects of ILC2-induced MDSC functionality on the microenvironment differed in a metastatic-stage-specific manner. Our findings indicate that ILC2s may induce the immunosuppressive functions of MDSCs during the later stages of metastasis. Concomitantly, ILC2 may instigate extracellular matrix remodeling by PMN-MDSC activation during the early stages of metastasis. These metastatic-stage-specific changes may contribute to metastatic tumor growth in the microenvironment of breast cancer lung metastasis.

Elevated Plasma Soluble PD-L1 Levels in Out-of-Hospital Cardiac Arrest Patients.

Background: A deregulated immune system has been implicated in the pathogenesis of post-cardiac arrest syndrome (PCAS). A soluble form of programmed cell death-1 (PD-1) ligand (sPD-L1) has been found at increased levels in cancer and sustained inflammation, thereby deregulating immune functions. Here, we aim to study the possible involvement of sPD-L1 in PCAS. Methods: Thirty out-of-hospital cardiac arrest (OHCA) patients consecutively admitted to the ER of Mie University Hospital were prospectively enrolled. Plasma concentrations of sPD-L1 were measured by an enzyme-linked immunosorbent assay in blood samples of all 30 OHCA patients obtained during cardiopulmonary resuscitation (CPR). In 13 patients who achieved return-of-spontaneous-circulation (ROSC), sPD-L1 levels were also measured daily in the ICU. Results: The plasma concentrations of sPD-L1 in OHCA were significantly increased; in fact, to levels as high as those observed in sepsis. sPD-L1 levels during CPR correlated with reduced peripheral lymphocyte counts and increased C-reactive protein levels. Of 13 ROSC patients, 7 cases survived in the ICU for more than 4 days. A longitudinal analysis of sPD-L1 levels in the 7 ROSC cases revealed that sPD-L1 levels occurred in parallel with organ failure. Conclusions: This study suggests that ischemia- reperfusion during CPR may aberrantly activate immune and endothelial cells to release sPD-L1 into circulation, which may play a role in the pathogenesis of immune exhaustion and organ failures associated with PCAS.

Cellular and Exosomal Regulations of Sepsis-Induced Metabolic Alterations.

Sepsis is a sustained systemic inflammatory condition involving multiple organ failures caused by dysregulated immune response to infections. Sepsis induces substantial changes in energy demands at the cellular level leading to metabolic reprogramming in immune cells and stromal cells. Although sepsis-associated organ dysfunction and mortality have been partly attributed to the initial acute hyperinflammation and immunosuppression precipitated by a dysfunction in innate and adaptive immune responses, the late mortality due to metabolic dysfunction and immune paralysis currently represent the major problem in clinics. It is becoming increasingly recognized that intertissue and/or intercellular metabolic crosstalk via endocrine factors modulates maintenance of homeostasis, and pathological events in sepsis and other inflammatory diseases. Exosomes have emerged as a novel means of intercellular communication in the regulation of cellular metabolism, owing to their capacity to transfer bioactive payloads such as proteins, lipids, and nucleic acids to their target cells. Recent evidence demonstrates transfer of intact metabolic intermediates from cancer-associated fibroblasts via exosomes to modify metabolic signaling in recipient cells and promote cancer progression. Here, we review the metabolic regulation of endothelial cells and immune cells in sepsis and highlight the role of exosomes as mediators of cellular metabolic signaling in sepsis.

Identification of a small pericardial effusion on contrast-enhanced computed tomography indicating cardiac perforation and pericardial injury following blunt trauma: A case report.

Blunt trauma may cause cardiac perforation requiring emergency surgical repair. Cardiac perforations are usually diagnosed by the presence of a pericardial effusion on echocardiography. However, cardiac perforations and pericardial effusions are sometimes too small to detect, resulting in underdiagnosis. In this case report, we describe a 22-year-old man who was involved in a traffic accident, admitted in a state of shock, and was initially treated for tension pneumothorax and liver and spleen injuries. His initial computed tomography scans revealed a small region of enhancement, corresponding to a small pericardial effusion, indicative of a cardiac perforation. Thus, an emergency median sternotomy was performed. He was diagnosed with perforation of the left atrial ear and right atrium, which were repaired surgically. His liver and spleen injuries were also treated, and the patient was discharged 44 days after admission. The detection of a small pericardial effusion on enhanced computed tomography enabled rapid diagnosis of a cardiac perforation and ensured emergency surgical repair could be performed as soon as possible. LEARNING OBJECTIVES: •To acknowledge the difficulty of diagnosing cardiac perforation in patients with pericardial injury, based on conventional signs of blunt cardiac injury, such as sternal fracture, serum cardiac enzymes, and hemothorax.•To recognize that a small pericardial effusion on enhanced computed tomography scans is an important finding that should raise suspicion of cardiac perforation and pericardial injury.

Veno-arterial extracorporeal membrane oxygenation and targeted temperature management in tricyclic antidepressant-induced cardiac arrest: A case report and literature review.

RATIONALE: Cardiotoxicity is a common cause of death in tricyclic antidepressant (TCA) intoxication. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is effective in critically ill poisoned patients who do not respond to conventional therapies, and targeted temperature management (TTM) is associated with improved neurological outcomes and mortality in comatose out-of-hospital cardiac arrest survivors. However, few reports have documented cases of TCA intoxication that required intensive care, including VA-ECMO or TTM. PATIENT CONCERNS: A 19-year-old Japanese man with a history of depression was brought to our hospital because he was in a comatose state with a generalized seizure. Before admission, he had taken an unknown amount of amitriptyline. DIAGNOSIS: After intubation, the electrocardiogram (ECG) displayed a wide QRS complex tachycardia, and the patient suffered from cardiovascular instability despite intravenous bolus of sodium bicarbonate. At 200 minutes after ingestion, he experienced a TCA-induced cardiac arrest. INTERVENTIONS: We initiated VA-ECMO 240 minutes after ingestion. The hemodynamic status stabilized, and the ECG abnormality improved gradually. In addition, we initiated targeted temperature management (TTM) with a target temperature of 34°C. OUTCOMES: Twenty seven hours after starting the pump, the patient was weaned off the VA-ECMO. After completing the TTM, his mental status improved, and he was extubated on day 5. He was discharged on day 15 without neurological impairment, and the post-discharge course was uneventful. LESSONS: First, VA-ECMO is effective in patients with TCA-induced cardiac arrest. Second, routine ECG screening during VA-ECMO support is useful for assessing the timing to wean off the VA-ECMO, as well as the degree of cardiotoxicity. Third, TTM is safe in comatose survivors of cardiac arrest caused by severe TCA intoxication.

The Lectin-Like Domain of Thrombomodulin Inhibits ß1 Integrin-Dependent Binding of Human Breast Cancer-Derived Cell Lines to Fibronectin.

Thrombomodulin is a molecule with anti-coagulant and anti-inflammatory properties. Recently, thrombomodulin was reported to be able to bind extracellular matrix proteins, such as fibronectin and collagen; however, whether thrombomodulin regulates the binding of human breast cancer-derived cell lines to the extracellular matrix remains unknown. To investigate this, we created an extracellular domain of thrombomodulin, TMD123-Fc, or domain deletion TM-Fc proteins (TM domain 12-Fc, TM domain 23-Fc) and examined their bindings to fibronectin in vitro by ELISA. The lectin-like domain of thrombomodulin was found to be essential for the binding of the extracellular domain of thrombomodulin to fibronectin. Using a V-well cell adhesion assay or flow cytometry analysis with fluorescent beads, we found that both TMD123-Fc and TMD12-Fc inhibited the binding between ß1 integrin of human breast cancer-derived cell lines and fibronectin. Furthermore, TMD123-Fc and TMD12-Fc inhibited the binding of activated integrins to fibronectin under shear stress in the presence of Ca2+ and Mg2+ but not under strong integrin-activation conditions in the presence of Mg2+ without Ca2+. This suggests that thrombomodulin Fc fusion protein administered exogenously at a relatively early stage of inflammation may be applied to the development of new therapies that inhibit the binding of ß1 integrin of breast cancer cell lines to fibronectin.

Sepsis Induces Deregulation of IL-13 Production and PD-1 Expression in Lung Group 2 Innate Lymphoid Cells.

ABSTRACT: Deregulation of the immune system in sepsis plays the central role in the pathogenesis of multiple organ failure including septic lung injury. Group 2 innate lymphoid cells (ILC2s) have emerged as a new player in regulating immune homeostasis in the lung; however, the role of ILC2s in lung injury in sepsis remains poorly understood. Here, we investigated temporal changes in stimulatory and inhibitory receptor expression and intracellular type 2 cytokine expression of ILC2s in the lung using a cecal ligation and puncture mouse sepsis model. We found that IL-13 production by ILC2s, which were predominately composed of the resident natural ILC2 subset rather than the migratory inflammatory ILC2 subset, was reduced in the lungs of sepsis mice on day 1 and gradually restored through day 7. Although the expression levels of ST2 and inducible T-cell costimulator (stimulatory receptors) were high, IL-13 production by ILC2s was reduced while showing high programmed cell death 1 (PD-1) (inhibitory receptor) expression. Furthermore, using IL-33 knockout mice, we have shown that IL-33 regulates the capacity of ILC2s to produce IL-13, possibly through the modulation of ST2 and PD-1 expression and signaling in the septic lung. To the best of our knowledge, this is the first report showing differential costimulatory/inhibitory receptor expression on ILC2s in a septic lung in the context of an IL-33/IL-13 pathway-mediated type 2 immune response in the progression and resolution of inflammation. Our present findings contribute to a better understanding of the underlying immunological mechanism of ILC2s and may fill the critical knowledge gap regarding immune homeostasis in the lung that hampers the development of new therapeutic strategies for sepsis-induced acute lung injury.

Intestinal Epithelium-Derived Luminally Released Extracellular Vesicles in Sepsis Exhibit the Ability to Suppress TNF-a and IL-17A Expression in Mucosal Inflammation.

Sepsis is a systemic inflammatory disorder induced by a dysregulated immune response to infection resulting in dysfunction of multiple critical organs, including the intestines. Previous studies have reported contrasting results regarding the abilities of exosomes circulating in the blood of sepsis mice and patients to either promote or suppress inflammation. Little is known about how the gut epithelial cell-derived exosomes released in the intestinal luminal space during sepsis affect mucosal inflammation. To study this question, we isolated extracellular vesicles (EVs) from intestinal lavage of septic mice. The EVs expressed typical exosomal (CD63 and CD9) and epithelial (EpCAM) markers, which were further increased by sepsis. Moreover, septic-EV injection into inflamed gut induced a significant reduction in the messaging of pro-inflammatory cytokines TNF-a and IL-17A. MicroRNA (miRNA) profiling and reverse transcription and quantitative polymerase chain reaction (RT-qPCR) revealed a sepsis-induced exosomal increase in multiple miRNAs, which putatively target TNF-a and IL-17A. These results imply that intestinal epithelial cell (IEC)-derived luminal EVs carry miRNAs that mitigate pro-inflammatory responses. Taken together, our study proposes a novel mechanism by which IEC EVs released during sepsis transfer regulatory miRNAs to cells, possibly contributing to the amelioration of gut inflammation.

The Role of Innate Lymphoid Cells in the Regulation of Immune Homeostasis in Sepsis-Mediated Lung Inflammation.

Septic shock/severe sepsis is a deregulated host immune system response to infection that leads to life-threatening organ dysfunction. Lung inflammation as a form of acute lung injury (ALI) is often induced in septic shock. Whereas macrophages and neutrophils have been implicated as the principal immune cells regulating lung inflammation, group two innate lymphoid cells (ILC2s) have recently been identified as a new player regulating immune homeostasis. ILC2 is one of the three major ILC subsets (ILC1s, ILC2s, and ILC3s) comprised of newly identified innate immune cells. These cells are characterized by their ability to rapidly produce type 2 cytokines. ILC2s are predominant resident ILCs and, thereby, have the ability to respond to signals from damaged tissues. ILC2s regulate the immune response, and ILC2-derived type 2 cytokines may exert protective roles against sepsis-induced lung injury. This focused review not only provides readers with new insights into the signaling mechanisms by which ILC2s modulate sepsis-induced lung inflammation, but also proposes ILC2 as a novel therapeutic target for sepsis-induced ALI.

Pyogenic spondylodiscitis of the lumbar spine related to anastomotic fistula after surgery for esophageal cancer: a case report.

BACKGROUND: Pyogenic spondylodiscitis is an extremely rare complication of esophagectomy for esophageal cancer. CASE PRESENTATION: A 70-year-old Japanese man, with a previous medical history of type 2 diabetes mellitus, coronary artery disease, and laryngeal cancer, received neoadjuvant chemotherapy and underwent thoracoscopic esophagectomy with gastric tube reconstruction for advanced esophageal cancer. Cervical esophagogastrostomy with circular-stapled end-to-side anastomosis was performed. However, partial necrosis in the gastric tube developed to form refractory anastomotic fistula. Two months after the initial surgery, debridement and free jejunal transfer reconstruction with the pectoralis major muscle flap were performed. Although the postoperative course of the second surgery was uneventful, the patient complained of severe lower back pain and fever. The patient was diagnosed with pyogenic spondylodiscitis according to the results of the magnetic resonance imaging. Enterobacter cloacae were isolated from the arterial blood culture. Sensitive antibiotics were administered continuously, and the patient required to use a lumbar corset for 2 months. Subsequently, his physiological signs and symptoms had completely disappeared. CONCLUSION: To the best of our knowledge, this case study is the first study that reported pyogenic spondylodiscitis of the lumbar spine, a complication of cervical anastomotic fistula after surgery for advanced esophageal cancer.

Anti-adhesive effects of human soluble thrombomodulin and its domains.

We reported previously that leukocyte ß2 integrins (LFA-1 and Mac-1) bind to the serine/threonine-rich domain of thrombomodulin (TM) expressed on vascular endothelial cells (VECs). Recombinant human soluble TM (rhsTM, TMD123) has been approved as a therapeutic drug for septic disseminated intravascular coagulation. However, the roles of TMD123 on the adhesion of leukocyte integrins to VECs remain unclear. In the current study, we have revealed that an integrin-dependent binding between human peripheral blood mononuclear cells (PBMCs) and VECs was inhibited by TMD123. Next, using mutant proteins composed of isolated TM extracellular domains, we examined the structural characteristics responsible for the anti-adhesion properties of TMD123. Namely, we investigated whether the effects of the binding of TM and leukocytes was inhibited by the administration of TMD123. In fact, we confirmed that TMD123, TMD1, and TMD3 inhibited the binding of PBMCs to the immobilized recombinant proteins TMD123 and TMD3. These results indicate that TMD123 inhibited the adhesion of leukocytes to endothelial cells via ß2 integrins and endothelial TM. Moreover, since TMD1 might bind to leukocytes via other adhesion receptors than integrins, TMD1 and TMD3 appear to inhibit leukocyte binding to TM on VECs via different mechanisms. In summary, TMD123 (rhsTM), TMD1 or TMD3 is a promising treatment option for sepsis that attenuates integrin-dependent binding of leukocytes to VECs, and may inhibit the undesirable adhesion and migration of leukocytes to VECs in sepsis.

Massive retroperitoneal hematoma following colonoscopy: A case report.

RATIONALE: Colonoscopy has been used for screening and treatment of diseases worldwide. Endoscopic mucosal resection (EMR) has many major complications such as colon perforation and bleeding. However, cases of minor complications have also been reported. Here, we present a case of massive retroperitoneal hematoma, as a minor complication, after colonoscopy. PATIENT CONCERNS: A 57-year-old man was admitted to our hospital because of abdominal pain. He had no past medical history relating to his present condition, and he received EMR at another hospital 11 days before his admission. Dynamic computed tomography (CT) was performed, which showed a massive retroperitoneal hematoma near the third portion of the duodenum. DIAGNOSIS: The patient had a superior mesenteric vein injury after the colonoscopy. OUTCOMES: The patient did not complain of nausea or vomiting and was discharged after 43 days. LESSONS: Although massive retroperitoneal hematoma is a minor complication after colonoscopy, it can be life threatening; thus, we need to know more about this complication. Dynamic CT may be useful in detecting whether the bleeding occurs from the artery or not.

Incidentally detected splenogonadal fusion in a laparoscopic transabdominal preperitoneal hernia repair operation: A case report.

INTRODUCTION: Splenogonadal fusion (SGF) is a rare congenital malformation in which the spleen is connected to the gonad. Few SGF cases have been reported in the English scientific literature, and we are unaware of any previous case reports of SGF with inguinal hernia by laparoscopic transabdominal preperitoneal hernia repair (TAPP). Here, we report a case of SGF that was incidentally detected during a TAPP procedure, with an uneventful postoperative course without complications. PRESENTATION OF CASE: A 76-year-old male presented with a 10-year history of left inguinal swelling. He was diagnosed with a left inguinal hernia, and we performed TAPP. Laparoscopy revealed the left inguinal hernia and two reddish-purple masses, one located close to the left inguinal ring. A cord of soft tissue extended cranially from the mass to the spleen, and passed through the left internal inguinal ring caudally. We cut the cord for mesh placement and to make an accurate diagnosis of the mass. Pathological and intraoperative findings indicated a diagnosis of continuous SGF. DISCUSSION: We observed two important clinical issues in this case. First, the potential for incidental diagnoses of SGF may be increasing. Second, to our knowledge, this is the first case report of a patient with SGF identified by TAPP. Such a therapeutic strategy for incidentally detected SGF has not been described; here we report a successful experience. CONCLUSION: To our knowledge, this is the first report of a patient with SGF diagnosed by a TAPP procedure. The postoperative course was uneventful using our method.

Cecal Volvulus Following Elective Laparoscopic Cholecystectomy: A Case Report.

Cecal volvulus is characterized by torsion of the cecum around its own mesentery. However, cecal volvulus rarely develops soon after elective laparoscopic cholecystectomy. We report on a case of cecal volvulus that developed in a 54-year-old women 1 day after elective laparoscopic cholecystectomy and was successfully treated via colonoscopic decompression. The symptoms gradually improved in conjunction with recovery from postoperative ileus. Whether the incidence of volvulus has increased with the use of laparoscopic procedures, including laparoscopic cholecystectomy, has yet to be determined. Considering the current trend toward minimally invasive surgery, cecal volvulus should be considered in patients who have postoperative abdominal pain and distention.

Chylous ascites associated with intestinal obstruction from volvulus due to Petersen's hernia: report of a case.

BACKGROUND: Chylous ascites is an uncommon finding which is usually associated with recent abdominal/oncologic or retroperitoneal surgery. It is not usually seen in cases of acute obstruction. CASE PRESENTATION: A patient who had previously undergone a laparoscopy-assisted distal gastrectomy with Roux-en-Y reconstruction for early gastric cancer presented with acute abdominal pain and epigastric fullness. Computed tomography suggested small bowel obstruction due to volvulus. We were able to reduce the volvulus and close a Petersen's hernia without resecting the bowel; a large amount of chylous ascites was an incidental finding. CONCLUSIONS: We present a case of chylous ascites occurring in a setting of small bowel obstruction due to Petersen's hernia, 3 years after successful distal gastrectomy for early gastric cancer, with no evidence of tumor recurrence.