Comparison of metronidazole versus clarithromycin in first-line vonoprazan-based triple therapy for Helicobacter pylori: A multicenter randomized trial in Japan.

Background and Aim: To date, no randomized trials have compared the efficacy of 7-day vonoprazan, amoxicillin, and metronidazole triple therapy (VAM) versus 7-day vonoprazan, amoxicillin, and clarithromycin triple therapy (VAC) as a first-line treatment for Helicobacter pylori eradication. This study was performed to compare the efficacy of VAM and VAC as first-line treatments. Methods: This prospective multicenter randomized trial was performed in Japan and involved 124 H. pylori-positive patients without a history of eradication. Patients without antibiotic resistance testing of H. pylori were eligible. The patients were randomized to receive either VAC (vonoprazan 20 mg + amoxicillin 750 mg + clarithromycin 200 or 400 mg twice a day) or VAM (vonoprazan 20 mg + amoxicillin 750 mg + metronidazole 250 mg twice a day) for 7 days, with stratification by age and sex. Eradication success was evaluated using the 13C-urea breath test. We evaluated safety using patient questionnaires (UMIN000025773). Results: The intention-to-treat and per-protocol eradication rates of VAM were 91.3% (95% confidence interval [CI], 82.0-96.7%) and 92.6% (95% CI, 83.7-97.6%), respectively, and those of VAC were 89.1% (95% CI, 77.8-95.9%) and 96.1% (95% CI, 86.5-99.5%), respectively. No significant difference was observed between VAM and VAC in either analysis (P = 0.76 and P = 0.70, respectively). Abdominal fullness was more frequent in patients who received VAM than VAC. Conclusions: These findings suggest that VAM as a first-line treatment in Japan can be categorized as grade B (intention-to-treat cure rate of 90-95%) and have potential as a first-line national insurance -approved regimen.

Lethal disseminated intravascular coagulation induced by primary and metastatic neuroendocrine prostate cancer.

Introduction: Neuroendocrine prostate cancer has a poor prognosis. Although disseminated intravascular coagulation associated with malignancy can be lethal, it very rarely occurs among patients with primary neuroendocrine prostate cancer. Case presentation: An 80-year-old man presented to our hospital with bloody sputum. Blood examination indicated disseminated intravascular coagulation. Serum levels of prostate-specific antigen and neuron-specific enolase were 44.274 and 176 ng/mL, respectively. Core needle biopsies of an irregular mass in the prostate and a metastatic tumor in the left iliac bone showed similar neuroendocrine carcinoma cells. Hence, the patient was diagnosed with disseminated intravascular coagulation associated with primary and metastatic neuroendocrine prostate cancer. Unfortunately, he passed away 3 weeks after the biopsies. Conclusion: Given the difficulty of effectively treating metastatic neuroendocrine prostate cancer among patients in poor physical condition due to disease progression, identifying a new well-tolerated treatment modality is imperative.

Unusual lymphatic spread: Autopsy report of rectal obstruction from high-grade micropapillary urothelial carcinoma in the urinary bladder.

Bladder cancer commonly metastasizes to the lymph nodes. Rectal obstruction (RO) caused by bladder cancer has been reported rarely, and its underlying mechanism remains unclear. Herein, we present an autopsy case of a 67-year-old man with RO caused by urothelial carcinoma (UC) with a micropapillary variant in the bladder. The autopsy showed high-grade UC infiltrating the rectum via the bladder's lateral pedicle, and widely spreading within the retroperitoneum due to lymphatic dissemination. Given that RO caused by bladder cancer is typically diagnosed after it has become a systemic disease, it is crucial to consider systemic treatment for the patient.

Complete response and long­term survival after stereotactic body radiotherapy in a patient with liver metastasis from α­fetoprotein­producing gastric cancer: A case report.

α-Fetoprotein (AFP)-producing gastric carcinoma (GC) (AFPGC) is a special subtype of GC that is clinically characterized by a high incidence of liver metastasis and poor prognosis. The present study reported the case of a patient with AFPGC who showed complete response (CR) after stereotactic body radiotherapy (SBRT) for liver metastasis. A 76-year-old male patient underwent total gastrectomy with D2 lymph node dissection for GC. The excised tumor was diagnosed as AFPGC due to the patient's high serum AFP level (3,763 ng/ml) and AFP expression on immunohistochemistry. The patient was diagnosed with liver metastasis two months after the surgery. 18F-fluorodeoxyglucose positron emission tomography indicated that the metastasis was a single recurrent focus. Although the patient underwent seven cycles of chemotherapy with S-1-based regimens, the metastatic tumor showed only a minor response despite the decrease in serum AFP levels. To realize high-quality disease control, SBRT was performed on the liver tumor (total dose of 48 Gy in four fractions). The metastasis showed a significant response two weeks after the completion of SBRT and CR two years later. CR was sustained and the patient survived with no evidence of recurrence 62 months after the diagnosis of liver metastasis. Literature data on the efficacy of radiotherapy for liver metastasis from AFPGC remain scarce. The present case report suggests that SBRT has high efficacy for oligometastatic diseases and may be included as an indication for the treatment of liver metastasis from AFPGC.

First case of synchronous Leydig cell tumor and spermatocytic tumor in the unilateral testis.

Both Leydig cell tumor (LCT), which is a sex cord-stromal tumor, and spermatocytic tumor (ST), which is a germ cell tumor, are rare testicular tumors. Synchronous LCT and ST in the unilateral testis are extremely rare because of their different origins. Herein, we report the case of an 84-year-old male patient with right scrotal swelling due to a testicular tumor. His age was out of the onset peak age of LCT but within ST. To the best of our knowledge, this is the first case with synchronous LCT and ST in the unilateral testis.

Anti-SARS-CoV-2 IgG antibody after the second and third mRNA vaccinations in staff and residents in a nursing home with a previous COVID-19 outbreak in Niigata, Japan.

This study measured IgG antibody titers against spike (S) and nucleocapsid (N) proteins of SARS-CoV-2 before vaccination and after the second and third doses of an mRNA vaccine in staff and residents of a nursing home in Niigata, Japan. The study included 52 staff members, of whom six (11.5%) were previously infected with SARS-CoV-2, and 32 older residents, of whom 22 (68.8%) were previously infected. All participants received the first two doses in April-July 2021 and a third dose in January-March 2022. In staff, the median anti-S antibody titers (interquartile range) in previously infected and SARS-CoV-2-naïve individuals before vaccination were 960 (592-1,926) and 0.5 (0.0-2.1) arbitrary units (AU)/mL. Anti-S antibody titers 5 months after the second and third doses in previously infected staff were 7,391 (5,230-7,747) and 10,195 (5,582-13,886) AU. In residents, the median anti-S antibody titers in previously infected and naïve individuals before vaccination were 734 (425-1,934) and 1.1 (0.0-3.1) AU/mL. Anti-S antibody titers at 5 months after the second and third doses in previously infected residents were 15,872 (9,683-21,557) and 13,813 (6,689-20,839) AU/mL; however, there were no significant differences in titers between the second and third doses in previously infected residents. Anti-N antibody titers were higher in previously infected than naïve individuals, and titers decreased chronologically.

Immunohistochemical detection of hepatocyte nuclear factor-4α in vertebrates.

Hepatocyte nuclear factor-4α (HNF4α) presents in multiple isoforms generated using alternative promoter (P1 and P2) and splicing. Neither conservation of tissue distribution of HNF4α isoforms, nor presence of alternative promoter usage is known. In this study, to detect the expression of HNF4α in some species of animals, we have applied monoclonal antibodies against P1 (K9218) and P2 (H6939) promoter-driven and P1/P2 promoter-driven H1415 HNF4α for immunohistochemistry and western blot analysis. Antibody K9218 was observed in the hepatocytes, proximal tubules of the kidney, and epithelial cells in the mucosa of the small intestine and colon of rats, chicken, and tortoise, whereas antibody H6939 signal were detected in the stomach, pancreas, bile duct, and pancreatic duct of human and rats. The signal for antibody K9218 was recognized in tissues of a wide range of mammals, bird, reptile, amphibian, and fish as well. Antibody H1415 displayed a positive reaction in hepatocytes and intestinal epithelial cells in chicken and tortoise, whereas the bile duct, mucosal epithelial cells in the stomach, or pancreas in these animals were negative. Western blotting showed the binding of the antibody with HNF4α protein from each animal. The sequence of human HNF4α was 100% identical to murine and rat HNF4α, 88.9% to chicken, 77.8% to Xenopus HNF4α, and 81.5% to medaka. However, the specific part of human and invertebrate Drosophila HNF4 shares only 14.8% sequence identity. This antibody is useful for detecting HNF4α isoforms in a wide range of vertebrates, and suggests many insights into animal evolution.

M2-polarized macrophages relate the clearance of gastric lanthanum deposition.

Previous reports have suggested that mucosal barrier failure allows lanthanum to stray into the lamina propria, and macrophages play an important role for the clearance. However, there is no report to analyze the polarity of phagocytizing macrophages. We suggested that M2 macrophage potentially played a major role in the clearance of lanthanum.

Phylogeographic analysis of human influenza A and B viruses in Myanmar, 2010-2015.

We investigated the circulation patterns of human influenza A and B viruses in Myanmar between 2010 and 2015 by analyzing full HA genes. Upper respiratory tract specimens were collected from patients with symptoms of influenza-like illness. A total of 2,860 respiratory samples were screened by influenza rapid diagnostic test, of which 1,577 (55.1%) and 810 (28.3%) were positive for influenza A and B, respectively. Of the 1,010 specimens that were positive for virus isolation, 370 (36.6%) were A(H1N1)pdm09, 327 (32.4%) were A(H3N2), 130 (12.9%) B(Victoria), and 183 (18.1%) were B(Yamagata) viruses. Our data showed that influenza epidemics mainly occurred during the rainy season in Myanmar. Our three study sites, Yangon, Pyinmana, and Pyin Oo Lwin had similar seasonality and circulating type and subtype of influenza in a given year. Moreover, viruses circulating in Myanmar during the study period were closely related genetically to those detected in Thailand, India, and China. Phylogeographic analysis showed that A(H1N1)pdm09 viruses in Myanmar originated from Europe and migrated to other countries via Japan. Similarly, A(H3N2) viruses in Myanmar originated from Europe, and disseminated to the various countries via Australia. In addition, Myanmar plays a key role in reseeding of influenza B viruses to Southeast Asia and East Asia as well as Europe and Africa. Thus, we concluded that influenza virus in Myanmar has a strong link to neighboring Asian countries, Europe and Oceania.

Histone demethylase JMJD1A coordinates acute and chronic adaptation to cold stress via thermogenic phospho-switch.

In acute cold stress in mammals, JMJD1A, a histone H3 lysine 9 (H3K9) demethylase, upregulates thermogenic gene expressions through ß-adrenergic signaling in brown adipose tissue (BAT). Aside BAT-driven thermogenesis, mammals have another mechanism to cope with long-term cold stress by inducing the browning of the subcutaneous white adipose tissue (scWAT). Here, we show that this occurs through a two-step process that requires both ß-adrenergic-dependent phosphorylation of S265 and demethylation of H3K9me2 by JMJD1A. The histone demethylation-independent acute Ucp1 induction in BAT and demethylation-dependent chronic Ucp1 expression in beige scWAT provides complementary molecular mechanisms to ensure an ordered transition between acute and chronic adaptation to cold stress. JMJD1A mediates two major signaling pathways, namely, ß-adrenergic receptor and peroxisome proliferator-activated receptor-γ (PPARγ) activation, via PRDM16-PPARγ-P-JMJD1A complex for beige adipogenesis. S265 phosphorylation of JMJD1A, and the following demethylation of H3K9me2 might prove to be a novel molecular target for the treatment of metabolic disorders, via promoting beige adipogenesis.

Prolonged postoperative ileus in a patient with primary pneumatosis cystoides intestinalis: a case report.

BACKGROUND: Pneumatosis cystoides intestinalis (PCI) is a rare disease characterized by multiple gas-filled cysts in the intestinal wall and is associated with various comorbidities. We report herein a case of intractable paralytic ileus caused by primary PCI. CASE PRESENTATION: A 73-year-old man visited out hospital complaining of abdominal pain and vomiting. He had been hospitalized twice for intestinal obstruction in the past 2 months. Based on his history of appendectomy, mechanical bowel obstruction caused by adhesion was diagnosed, and the patient underwent surgery. However, laparotomy revealed small bowel dilatation despite the absence of obstruction or stenosis. Multiple nodules were found in the wall of the dilated bowel loops. The dilated jejunum was excised. Histological examination revealed that the nodules were small gas-filled cysts, suggesting PCI. We made a diagnosis of ileus with underlying PCI and managed the patient conservatively. A large amount of nasogastric tube drainage continued for a long period postoperatively. The patient underwent relaparotomy 35 days after the first operation. The upper jejunum was markedly dilated, although no mechanical stenosis was found. The atonic, dilated jejunum was excised and the ileal stump was anastomosed to the duodenum in a double tract fashion. The patient underwent hyperbaric oxygen therapy because the ileus persisted postoperatively. His condition gradually improved and he was discharged 53 days after the second operation. CONCLUSIONS: Non-operative treatment is recommended for primary PCI of unknown etiology. Surgeons should be mindful of the possibility of primary PCI when considering surgical intervention for patients with bowel obstruction.

Roundabout1 distribution in neoplastic and non-neoplastic diseases with a focus on neoangiogenesis.

Slit and its receptor Roundabout (Robo) are important for neuronal development and neo-angiogenesis in various neoplastic and non-neoplastic diseases. Angiogenesis is a key factor for tumor growth and other angiogenesis-dependent diseases including rheumatoid arthritis, and chronic inflammation Recently, over-expression of Slit/Robo1 family proteins has been reported in several types of malignancy. We explored the expression of Robo1 in neoplastic and non-neoplastic diseases with a focus on newly formed blood vessels. Three hundred and thirty four cases of malignancy and forty five cases of angiogenic diseases were recruited. Using the A7241A Robo1 monoclonal antibody, Robo1 expression was validated by immunohistochemistry. Among malignant cases, endothelial cells of newly formed blood vessels in 283 tumors (84.7%) exhibited positive staining with above antibody. In non-neoplastic diseases, newly formed blood vessels were positive in 70.6% (12/17) cases of chronic inflammation, 100% (18/18) cases of pyogenic granuloma and 83.3% (5/6) cases of rheumatoid arthritis. Recently, newly anti-angiogenesis therapy is drawing attention as effective therapy for angiogenesis-dependent diseases without regard to their neoplastic or non-neoplastic nature. Our results showed a large number of neoplastic and non-neoplastic diseases showed positive staining for ROBO1 by immunohistochemistry. Thus, Robo1 targeted therapy may create new strategies for the treatment of angiogenic-dependent diseases through the suppression of angiogenesis. Further, besides the majority of liver cell carcinomas (23/28, 82.1%), Robo1 was positive in 100% of the squamous cell carcinoma of the esophagus, uterine cervix, lung and skin. Thus, immunohistochemical evaluation of Robo1 may be useful as an additional diagnostic tool for liver cell carcinomas and squamous cell carcinomas.

Vonoprazan- vs proton-pump inhibitor-based first-line 7-day triple therapy for clarithromycin-susceptible Helicobacter pylori: A multicenter, prospective, randomized trial.

BACKGROUND: The eradication rate of vonoprazan-based first-line triple therapy (combined with clarithromycin and amoxicillin) (V-AC) was reported to be 97.6% in patients with clarithromycin (CAM)-susceptible Helicobacter pylori in a phase III study, whereas our real-world, prospective, multicenter cohort study yielded an eradication rate <90%. OBJECTIVE: To validate the eradication rate of V-AC using CAM-susceptible testing in a multicenter, prospective, randomized trial. METHODS: We included 147 treatment-naïve H. pylori-positive patients [41 with CAM-resistant infections and 106 with CAM-susceptible infections]. The CAM-susceptible group patients were randomized to either the V-AC group (vonoprazan 20 mg bid, amoxicillin 750 mg bid, and clarithromycin 200 or 400 mg bid) or PPI-AC group (lansoprazole 30 mg, rabeprazole 10 mg, or esomeprazole 20 mg bid; amoxicillin 750 mg bid; and clarithromycin 200 or 400 mg bid). All CAM-resistant H. pylori were eradicated by V-AC, as measured by the urea breath test around 8 weeks after eradication. Safety was evaluated by patient questionnaires. RESULTS: The intention-to-treat and per-protocol eradication rates of V-AC in the CAM-susceptible H. pylori-infected patients were 87.3% (95% confidence interval 75.5%-94.7%) and 88.9% (77.4%-95.8%). The respective eradication rates of PPI-AC were 76.5% (62.5%-87.2%) and 86.7% (73.2%-94.9%). No significant difference was observed between the V-AC and PPI-AC regimes in terms of the intention-to-treat (P = .21) or per-protocol (P = .77) analyses. The questionnaire scores did not differ significantly between the groups. Both the intention-to-treat and per-protocol eradication rates of V-AC in the CAM-resistant patients were 82.9% (67.9%-92.8%). CONCLUSION: The eradication rate of V-AC treatment in the CAM-susceptible H. pylori-infected patients was <90%, as was that by PPI-AC, thus V-AC is not ideal regimen in CAM-susceptible H. pylori. However, the 82.9% eradication rate of V-AC in the CAM-resistant infections may indicate the potential of V-AC with modified dose, dosing interval, and treatment duration. (UMIN000016337).

The Superiority of Vonoprazan-based First-line Triple Therapy with Clarithromycin: A Prospective Multi-center Cohort Study on Helicobacter pylori Eradication.

Objective We evaluated the safety and efficacy of vonoprazan-based amoxicillin and clarithromycin 7-day triple therapy (VAC) in comparison to proton pump inhibitor (PPI)-based (PAC) as a first-line treatment and vonoprazan-based amoxicillin and metronidazole 7-day triple therapy (VAM) in comparison to PPI-based (PAM) as a second-line treatment for the eradication of Helicobacter pylori in Japan. Methods We performed a non-randomized, multi-center, parallel-group study to compare first-line VAC to PAC and second-line VAM to PAM. A pre-planned subgroup analysis on CAM resistance was also performed. Safety was evaluated with an adverse effects questionnaire (AEQ), which was completed by patients during therapy. Results The first-line eradication rates (ER) in the intention-to-treat (ITT) and per protocol (PP) analyses were 84.9% (95% CI: 81.9-87.6%, n=623) and 86.4% (83.5-89.1%, n=612), respectively, for VAC and 78.8% (75.3-82.0%, n=608) and 79.4% (76.0-82.6%, n=603), respectively, for PAC. The ER of VAC was higher than that of PAC in the ITT (p=0.0061) and PP analyses (p=0.0013). The ERs for VAC in patients with CAM-resistant and CAM-susceptible bacteria were 73.2% (59.7-84.2%, n=56) and 88.9% (83.4-93.1%, n=180), respectively. PAC was associated with higher AEQ scores for diarrhea, nausea, headache, and general malaise. In the second-line ITT and PP analyses VAM achieved ERs of 80.5% (74.6-85.6%, n=216) and 82.4% (76.6-87.3%, n=211), respectively, while PAM achieved ERs of 81.5% (74.2-87.4%, n=146) and 82.1% (74.8-87.9%, n=145), respectively. No significant differences were observed in the ITT (p=0.89) or PP (p=1.0) analyses. Conclusion The ER of first-line VAC was higher than that of PAC, but still <90%. No difference was observed between second-line VAM and PAM. Vonoprazan-based triple therapy was safe and well tolerated.

USP10 Is an Essential Deubiquitinase for Hematopoiesis and Inhibits Apoptosis of Long-Term Hematopoietic Stem Cells.

Self-renewal, replication, and differentiation of hematopoietic stem cells (HSCs) are regulated by cytokines produced by niche cells in fetal liver and bone marrow. HSCs must overcome stresses induced by cytokine deprivation during normal development. In this study, we found that ubiquitin-specific peptidase 10 (USP10) is a crucial deubiquitinase for mouse hematopoiesis. All USP10 knockout (KO) mice died within 1 year because of bone marrow failure with pancytopenia. Bone marrow failure in these USP10-KO mice was associated with remarkable reductions of long-term HSCs (LT-HSCs) in bone marrow and fetal liver. Such USP10-KO fetal liver exhibited enhanced apoptosis of hematopoietic stem/progenitor cells (HSPCs) including LT-HSCs but not of lineage-committed progenitor cells. Transplantation of USP10-competent bone marrow cells into USP10-KO mice reconstituted multilineage hematopoiesis. These results suggest that USP10 is an essential deubiquitinase in hematopoiesis and functions by inhibiting apoptosis of HSPCs including LT-HSCs.

Characteristic microglial features in patients with hereditary diffuse leukoencephalopathy with spheroids.

OBJECTIVE: To clarify the histopathological alterations of microglia in the brains of patients with hereditary diffuse leukoencephalopathy with spheroids (HDLS) caused by mutations of the gene encoding the colony stimulating factor-1 receptor (CSF-1R). METHODS: We examined 5 autopsied brains and 1 biopsy specimen from a total of 6 patients with CSF-1R mutations. Detailed immunohistochemical, biochemical, and ultrastructural features of microglia were examined, and quantitative analyses were performed. RESULTS: In layers 3 to 4 of the frontal cortex in HDLS brains, microglia showed relatively uniform and delicate morphology, with thin and winding processes accompanying knotlike structures, and significantly smaller areas of Iba1 immunoreactivity and lower numbers of Iba1-positive cells were evident in comparison with control brains. On the other hand, in layers 5 to 6 and the underlying white matter, microglia were distributed unevenly; that is, in some areas they had accumulated densely, whereas in others they were scattered. Immunoblot analyses of microglia-associated proteins, including CD11b and DAP12, revealed that HDLS brains had significantly lower amounts of these proteins than diseased controls, although Ki-67-positive proliferative microglia were not reduced. Ultrastructurally, the microglial cytoplasm and processes in HDLS showed vesiculation of the rough endoplasmic reticulum and disaggregated polyribosomes, indicating depression of protein synthesis. On the other hand, macrophages were immunonegative for GLUT-5 or P2ry12, indicating that they were derived from bone marrow. INTERPRETATION: The pathogenesis of HDLS seems to be associated with microglial vulnerability and morphological alterations. Ann Neurol 2016;80:554-565.

RASAL3, a novel hematopoietic RasGAP protein, regulates the number and functions of NKT cells.

Ras GTPase-activating proteins negatively regulate the Ras/Erk signaling pathway, thereby playing crucial roles in the proliferation, function, and development of various types of cells. In this study, we identified a novel Ras GTPase-activating proteins protein, RASAL3, which is predominantly expressed in cells of hematopoietic lineages, including NKT, B, and T cells. We established systemic RASAL3-deficient mice, and the mice exhibited a severe decrease in NKT cells in the liver at 8 weeks of age. The treatment of RASAL3-deficient mice with α-GalCer, a specific agonist for NKT cells, induced liver damage, but the level was less severe than that in RASAL3-competent mice, and the attenuated liver damage was accompanied by a reduced production of interleukin-4 and interferon-γ from NKT cells. RASAL3-deficient NKT cells treated with α-GalCer in vitro presented augmented Erk phosphorylation, suggesting that there is dysregulated Ras signaling in the NKT cells of RASAL3-deficient mice. Taken together, these results suggest that RASAL3 plays an important role in the expansion and functions of NKT cells in the liver by negatively regulating Ras/Erk signaling, and might be a therapeutic target for NKT-associated diseases.

Differential expression of pentraxin 3 in neutrophils.

Pentraxins belong to the superfamily of conserved proteins that are characterized by a cyclic multimeric structure. Pentraxin 3 (PTX3) is a long pentraxin which can be produced by different cell types upon exposure to various inflammatory signals. Inside the neutrophil PTX3 is stored in form of granules localized in the cytoplasm. Neutrophilic granules are divided into three types: azurophilic (primary) granules, specific (secondary) granules and gelatinase (tertiary) granules. PTX3 has been considered to be localized in specific (secondary) granules. Immunofluorescent analyses using confocal laser microscopic examination were performed to clarify the localization of all three groups of granules within the cytoplasm of the mature neutrophils and neutrophils stimulated with IL-8. Furthermore, PTX3 was localized in primary granules of promyelocyte cell line HL-60. As a result, we suggest that PTX3 is localized not only in specific granules, but is also partly expressed in primary and tertiary granules. After the stimulation with IL-8, irregular reticular structures called neutrophil extracellular traps (NETs) were formed, three types of granules were trapped by NETs and PTX3 showed partial colocalization with these granular components. PTX3 localized in all three types of granules in neutrophils may play important roles in host defense.

Protective effect of the long pentraxin PTX3 against histone-mediated endothelial cell cytotoxicity in sepsis.

Pentraxin 3 (PTX3), a member of the long pentraxin subfamily within the family of pentraxins, is a soluble pattern recognition molecule that functions in the innate immune system. Innate immunity affords the infected host protection against sepsis, a potentially life-threatening inflammatory response to infection. Extracellular histones are considered to be the main cause of septic death because of their cytotoxic effect on endothelial cells, which makes them a potential therapeutic target. We found that PTX3 interacted with histones to form coaggregates, which depended on polyvalent interactions and disorder in the secondary structure of PTX3. PTX3 exerted a protective effect, both in vitro and in vivo, against histone-mediated cytotoxicity toward endothelial cells. Additionally, the intraperitoneal administration of PTX3 reduced mortality in mouse models of sepsis. The amino-terminal domain of PTX3, which was required for coaggregation with histones, was sufficient to protect against cytotoxicity. Our results suggest that the host-protective effects of PTX3 in sepsis are a result of its coaggregation with histones rather than its ability to mediate pattern recognition. This long pentraxin-specific effect provides a potential basis for the treatment of sepsis directed at protecting cells from the toxic effects of extracellular histones.

PPARß/δ activation of CD300a controls intestinal immunity.

Macrophages are important for maintaining intestinal immune homeostasis. Here, we show that PPARß/δ (peroxisome proliferator-activated receptor ß/δ) directly regulates CD300a in macrophages that express the immunoreceptor tyrosine based-inhibitory motif (ITIM)-containing receptor. In mice lacking CD300a, high-fat diet (HFD) causes chronic intestinal inflammation with low numbers of intestinal lymph capillaries and dramatically expanded mesenteric lymph nodes. As a result, these mice exhibit triglyceride malabsorption and reduced body weight gain on HFD. Peritoneal macrophages from Cd300a-/- mice on HFD are classically M1 activated. Activation of toll-like receptor 4 (TLR4)/MyD88 signaling by lipopolysaccharide (LPS) results in prolonged IL-6 secretion in Cd300a-/- macrophages. Bone marrow transplantation confirmed that the phenotype originates from CD300a deficiency in leucocytes. These results identify CD300a-mediated inhibitory signaling in macrophages as a critical regulator of intestinal immune homeostasis.