Notch signaling without the APH-2/nicastrin subunit of gamma secretase in Caenorhabditis elegans germline stem cells.

The final step in Notch signaling activation is the transmembrane cleavage of Notch receptor by γ secretase. Thus far, genetic and biochemical evidence indicates that four subunits are essential for γ secretase activity in vivo: presenilin (the catalytic core), APH-1, PEN-2, and APH-2/nicastrin. Although some γ secretase activity has been detected in APH-2/nicastrin-deficient mammalian cell lines, the lack of biological relevance for this activity has left the quaternary γ secretase model unchallenged. Here, we provide the first example of in vivo Notch signal transduction without APH-2/nicastrin. The surprising dispensability of APH-2/nicastrin is observed in Caenorhabditis elegans germline stem cells (GSCs) and contrasts with its essential role in previously described C. elegans Notch signaling events. Depletion of GLP-1/Notch, presenilin, APH-1, or PEN-2 causes a striking loss of GSCs. In contrast, aph-2/nicastrin mutants maintain GSCs and exhibit robust and localized expression of the downstream Notch target sygl-1. Interestingly, APH-2/nicastrin is normally expressed in GSCs and becomes essential under conditions of compromised Notch function. Further insight is provided by reconstituting the C. elegans γ secretase complex in yeast, where we find that APH-2/nicastrin increases but is not essential for γ secretase activity. Together, our results are most consistent with a revised model of γ secretase in which the APH-2/nicastrin subunit has a modulatory, rather than obligatory role. We propose that a trimeric presenilin-APH-1-PEN-2 γ secretase complex can provide a low level of γ secretase activity, and that cellular context determines whether or not APH-2/nicastrin is essential for effective Notch signal transduction.

Plastic Wound Protector vs Surgical Gauze for Surgical Site Infection Reduction in Open GI Surgery: A Randomized Clinical Trial.

Importance: Surgical site infections (SSIs) are prevalent hospital-acquired infections with significant patient impacts and global health care burdens. The World Health Organization recommends using wound protector devices in abdominal surgery as a preventive measure to lower the risk of SSIs despite limited evidence. Objective: To examine the efficacy of a dual-ring, plastic wound protector in lowering the SSI rate in open gastrointestinal (GI) surgery irrespective of intra-abdominal contamination levels. Design, Setting, and Participants: This multicenter, patient-blinded, parallel-arm randomized clinical trial was conducted from August 2017 to October 2022 at 13 hospitals in an academic setting. Patients undergoing open abdominal bowel surgery (eg, for bowel perforation) were eligible for inclusion. Intervention: Patients were randomized 1:1 to a dual-ring, plastic wound protector to protect the incision site of the abdominal wall (experimental group) or a conventional surgical gauze (control group). Main Outcomes and Measures: The primary end point was the rate of SSI within 30 days of open GI surgery. Results: A total of 458 patients were randomized; after 1 was excluded from the control group, 457 were included in the intention-to-treat analysis (mean [SD] age, 58.4 [12.1] years; 256 [56.0%] male; 341 [74.6%] with a clean-contaminated wound): 229 in the wound protector group and 228 in the surgical gauze group. The overall SSI rate in the intention-to-treat analysis was 15.7% (72 of 458 patients). The SSI rate for the wound protector was 10.9% (25 of 229 patients) compared with 20.5% (47 of 229 patients) with surgical gauze. The wound protector significantly reduced the risk of SSI, with a relative risk reduction (RRR) of 46.81% (95% CI, 16.64%-66.06%). The wound protector significantly decreased the SSI rate for clean-contaminated wounds (RRR, 43.75%; 95% CI, 3.75%-67.13%), particularly for superficial SSIs (RRR, 42.50%; 95% CI, 7.16%-64.39%). Length of hospital stay was similar in both groups (mean [SD], 15.2 [10.5] vs 15.3 [10.2] days), as were the overall postoperative complication rates (20.1% vs 18.8%). Conclusions and Relevance: This randomized clinical trial found a significant reduction in SSI rates when a plastic wound protector was used during open GI surgery compared with surgical gaze, supporting the World Health Organization recommendation for use of wound protector devices in abdominal surgery. Trial Registration: ClinicalTrials.gov Identifier: NCT03170843.

Survival Outcomes after Elective or Emergency Surgery for Synchronous Stage IV Colorectal Cancer.

Patients with stage IV colorectal cancer (CRC) who have not undergone primary tumor resection (PTR) are at risk of sudden medical emergencies. Despite the ongoing controversy over the necessity and timing of PTR in patients with stage IV CRC, studies comparing the survival outcomes of elective and emergency surgery in this population are scarce. This is a retrospective study conducted at a single institute. The patients were divided into two groups: the elective surgery (ELS) group (n = 46) and the emergency surgery (EMS) group (n = 26). The primary outcome was 2-year overall survival (OS). During a median follow-up period of 27.0 months, the 2-year OS was significantly better in the ELS group (80% vs. 42.9%, p = 0.002). No significant differences were observed in the 2-year relapse-free survival and 30-day postoperative complication rates. Planning and performing elective surgery could help increase the survival rate of patients with synchronous stage IV CRC, especially those that undergo simultaneous or staged metastasectomy.

PLAG alleviates chemotherapy-induced thrombocytopenia via promotion of megakaryocyte/erythrocyte progenitor differentiation in mice.

Previously, PLAG (1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol, acetylated diglyceride) was reported to have an effect on the proliferation of hematopoietic stem cells (HSCs) or to contribute to the prevention of chemotherapy-induced neutropenia. In this study, we examined the role of PLAG in the differentiation of bone marrow cells from HSCs into progenitor cells in mice. After 15days, the lineage-negative cells, especially megakaryocyte/erythrocyte progenitors (MEP), were significantly increased in mice that received daily PLAG administration compared to those in the untreated mice. Furthermore, we explored the possibility that the PLAG-induced increase in MEP will contribute to reduction of chemotherapy-induced thrombocytopenia (CIT) in a thrombocytopenia mouse model. Mice were administrated 5-fluorouracil (5-FU) and PLAG. After 7days, bone marrow cells were analyzed. Treatment with 5-FU powerfully decreased myeloid precursor populations and treatment with 5-FU/PLAG resulted in reduction of decreased myeloid progenitor cell numbers. In addition, numbers of circulating platelets were also increased by PLAG treatment. Taken together, PLAG plays a role in differentiating HSCs toward MEP and alleviating chemotherapy-induced bone marrow cell reduction. Thus PLAG shows its potential to augment the therapeutic effect of anti-cancer drugs-induced thrombocytopenia.

The Therapeutic Effect of PLAG against Oral Mucositis in Hamster and Mouse Model.

Chemotherapy-induced mucositis can limit the effectiveness of cancer therapy and increase the risk of infections. However, no specific therapy for protection against mucositis is currently available. In this study, we investigated the therapeutic effect of PLAG (1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol, acetylated diglyceride) in 5-fluorouracil (5-FU)-induced oral mucositis animal models. Hamsters were administered 5-FU (80 mg/kg) intraperitoneally on days 0, 6, and 9. The animals' cheek pouches were then scratched equally with the tip of an 18-gage needle on days 1, 2, and 7. PLAG was administered daily at 250 mg/kg/day. PLAG administration significantly reduced 5-FU/scratching-induced mucositis. Dramatic reversal of weight loss in PLAG-treated hamsters with mucositis was observed. Histochemical staining data also revealed newly differentiated epidermis and blood vessels in the cheek pouches of PLAG-treated hamsters, indicative of recovery. Whole blood analyses indicated that PLAG prevents 5-FU-induced excessive neutrophil transmigration to the infection site and eventually stabilizes the number of circulating neutrophils. In a mouse mucositis model, mice with 5-FU-induced disease treated with PLAG exhibited resistance to body-weight loss compared with mice that received 5-FU or 5-FU/scratching alone. PLAG also dramatically reversed mucositis-associated weight loss and inhibited mucositis-induced inflammatory responses in the tongue and serum. These data suggest that PLAG enhances recovery from 5-FU-induced oral mucositis and may therefore be a useful therapeutic agent for treating side effects of chemotherapy, such as mucositis and cachexia.

PLAG (1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol) augments the therapeutic effect of pegfilgrastim on gemcitabine-induced neutropenia.

Granulocyte colony-stimulating factor (G-CSF) is widely used for preventing neutropenia during chemotherapy. Polyethylene glycol-conjugated granulocyte colony-stimulating factor (PEG-G-CSF, pegfilgrastim) serves the same purpose but has a longer half-life and greater stability than G-CSF. In this study, we investigated whether 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol, acetylated diglyceride (PLAG), augments the therapeutic effect of pegfilgrastim on chemotherapy-induced neutropenia. We compared neutrophil counts in four groups of mice: control mice, gemcitabine-treated mice, gemcitabine/pegfilgrastim-treated mice, and gemcitabine/pegfilgrastim/PLAG-treated mice. PLAG (50 mg/kg) was orally administered every day during the treatment course. CBC analysis showed that the group treated with PLAG experienced a dramatically increased neutrophil counts on the third day following pegfilgrastim treatment. PLAG had no effect on blood cell apoptosis and neutrophil release from bone marrow. Additionally, pegfilgrastim-induced CXCR2 expression in neutrophils was markedly decreased in PLAG-treated animals. These results suggest that PLAG plays a role in inhibiting neutrophil extravasation, giving rise to an increased number of circulating neutrophils when used with pegfilgrastim during gemcitabine treatment. These data support the potential for PLAG to be used with pegfilgrastim to treat or prevent chemotherapy-induced neutropenia by modulating neutrophil transmigration.

Genkwadaphnin promotes leukocyte migration by increasing CD44 expression via PKD1/NF-κB signaling pathway.

Genkwadaphnin (GD), an extract from the flower buds of Daphne genkwa Siebold & Zucc. (Thymelaeaceae) has been reported a significant anti-leukemic activity. However, its functional mechanism has not been defined well. To study the biological mechanism of GD function, we have investigated whether GD affects CD44 expression, which has a role in the regulation of immune cell motilities, and identified the related signaling pathways. GD treatment induced the increase of CD44 expression in a time- and concentration-dependent manner, which was specific for immune cells. GD activated PKD1/NF-κB signaling to induce CD44 expression, and resulted in the increased migration of K562 cells. In invasion assay, cell migratory ability was induced by GD and the transfection with CD44-specific short hairpin RNA resulted in reduction of its cell migration. GD treated human peripheral blood mononuclear cell (PBMC) were also shown the increased CD44 expression and migration. These data suggest that the induction of CD44 expression by GD treatment promotes immune cell transmigration resulting in the enhanced innate immunity.

Ingenane-type diterpene compounds from Euphorbia kansui modulate IFN-γ production through NF-κB activation.

BACKGROUND: Euphorbia kansui, a traditional medical herb, has been shown to have anti-tumour and anti-viral activities. Previously, we have reported that E. kansui increases interferon-gamma (IFN-γ) production in natural killer (NK) cells. However, it is not clear how E. kansui regulates IFN-γ secretion by NK cells. RESULTS: In this study, E. kansui was separated into six individual compounds from the same chloroform fraction so that the activity of each compound could be compared. E. kansui compounds induced IFN-γ secretion through the phosphorylation of protein kinase D and IκB kinase pathways. Furthermore, E. kansui compounds activated the translocation of p65, a sub-unit of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), to the nucleus and induced NF-κB at the transcriptional level. CONCLUSION: These findings suggest that E. kansui enhances IFN-γ secretion through the NF-κB pathway in NK cells. © 2015 Society of Chemical Industry.

Facial wrinkles as a predictor of decreased renal function.

AIMS: Oxidative stress generated either by exogenous or endogenous sources can lead to progressive organ damage and skin ageing over a long period of time. Moreover, some dermatological signs are independent of chronological ageing, and may reflect the long-term redox state of internal organs. Therefore, we hypothesized that there might be an association between facial wrinkles and decreased renal function, an oxidative stress-related disease. METHODS: A cross-sectional study was carried out in a Korean population of 264 adults aged 30 years and older. Facial wrinkle scores in the crow's-foot area were estimated using a standardized form of visual assessment. As an index of renal function, we determined estimated glomerular filtration rate (eGFR). Lipid hydroperoxide (LPO) assay was performed to measure the levels of oxidative stress. RESULTS: After adjusting for possible confounders, lower eGFRs and higher LPO levels were found in those with severe facial wrinkles. CONCLUSION: We conclude that severe facial wrinkles might be used as a predictive marker of decreased renal function, independently of age, gender and other established risk factors.