Deubiquitination Reactions on the Proteasome for Proteasome Versatility.

The 26S proteasome, a master player in proteolysis, is the most complex and meticulously contextured protease in eukaryotic cells. While capable of hosting thousands of discrete substrates due to the selective recognition of ubiquitin tags, this protease complex is also dynamically checked through diverse regulatory mechanisms. The proteasome's versatility ensures precise control over active proteolysis, yet prevents runaway or futile degradation of many essential cellular proteins. Among the multi-layered processes regulating the proteasome's proteolysis, deubiquitination reactions are prominent because they not only recycle ubiquitins, but also impose a critical checkpoint for substrate degradation on the proteasome. Of note, three distinct classes of deubiquitinating enzymes-USP14, RPN11, and UCH37-are associated with the 19S subunits of the human proteasome. Recent biochemical and structural studies suggest that these enzymes exert dynamic influence over proteasome output with limited redundancy, and at times act in opposition. Such distinct activities occur spatially on the proteasome, temporally through substrate processing, and differentially for ubiquitin topology. Therefore, deubiquitinating enzymes on the proteasome may fine-tune the degradation depending on various cellular contexts and for dynamic proteolysis outcomes. Given that the proteasome is among the most important drug targets, the biology of proteasome-associated deubiquitination should be further elucidated for its potential targeting in human diseases.

Effect of prophylactic abdominal drainage on postoperative pain in laparoscopic hemicolectomy for colon cancer: a single-center observational study in Korea.

Purpose: This study aimed to evaluate the effect of prophylactic abdominal drainage (AD) in laparoscopic hemicolectomy, focusing on assessing postoperative pain outcomes. Methods: Patients were categorized into two groups: those with and without AD (AD group vs. no-AD group). A numerical rating scale (NRS) was used to assess postoperative pain on each postoperative day (POD). Further, the inverse probability of treatment weighting (IPTW) method was used to reduce intergroup bias. Results: In total, 204 patients who underwent laparoscopic hemicolectomies by a single surgeon between June 2013 and September 2022 at a single institution were retrospectively reviewed. After adjusting for IPTW, NRS scores on POD 2 were significantly lower in the no-AD group (3.2 ± 0.8 vs. 3.4 ± 0.8, p = 0.043). Further examination of postoperative outcomes showed no statistically significant differences in complications between the AD (17.3%) and no-AD (12.4%) groups (p = 0.170). The postoperative length of hospital stay was 7.3 ± 2.8 days in the AD group and 6.9 ± 3.0 days in the no-AD group, with no significant difference (p = 0.298). Time to first flatus was 3.0 ± 0.9 days in the AD group and 2.7 ± 0.9 days in the no-AD group, with no significant difference (p = 0.078). Regarding readmission within 1 month, there were four cases each in the AD (2.3%) and no-AD (1.7%) groups, with no significant difference (p = 0.733). Conclusion: Laparoscopic hemicolectomy without AD resulted in no significant differences in postoperative clinical outcomes, except for postoperative pain. This finding suggests that prophylactic AD may exacerbate postoperative pain.

Pharmacokinetic and Pharmacodynamic Characteristics of Pelubiprofen Tromethamine vs. Pelubiprofen in Healthy Subjects.

Compared to pelubiprofen, a cyclooxygenase-2-selective inhibitor, pelubiprofen tromethamine has been reported to exhibit improved solubility and absorption. Pelubiprofen tromethamine combines the anti-inflammatory effect of pelubiprofen with the gastric protective function of tromethamine salt, making it a relatively safe class of non-steroidal anti-inflammatory drugs with low levels of gastrointestinal side effects in addition to its original analgesic, anti-inflammatory, and antipyretic effects. This study assessed the pharmacokinetic and pharmacodynamic characteristics of pelubiprofen and pelubiprofen tromethamine in healthy subjects. Two independent clinical trials were performed in healthy subjects using a randomized, open-label, oral, single-dose, two-sequence, four-period, crossover design. In Study I and Study II, subjects received 25 mg of pelubiprofen tromethamine and 30 mg of pelubiprofen tromethamine, respectively, with 30 mg of pelubiprofen being the reference. Study I fell within the bioequivalence study criteria. A trend of increased absorption and exposure for 30 mg of pelubiprofen tromethamine vs. the reference in Study II was observed. The maximum cyclooxygenase-2 inhibitory effect of 25 mg of pelubiprofen tromethamine was approximately 98% compared to the reference, showing no significant pharmacodynamic variation. It is thus predicted that 25 mg of pelubiprofen tromethamine would show no clinically significant discrepancies in clinical analgesic and antipyretic effects from 30 mg of pelubiprofen.

The Role and Function of Mucins and Its Relationship to Inflammatory Bowel Disease.

Mucus is present throughout the gastrointestinal tract and is essential for regulating gut microbiota homeostasis and preventing disease by protecting the gastrointestinal barrier from microorganisms, pathogens and toxins or other irritants. Mucin (MUC)-2 is a secreted protein produced by epithelial goblet cells as the main component of mucus. Defects in the gastrointestinal tract, such as inflammation and ulcers, cause damage to the mucus barrier, which can worsen mucus quality and reduce mucus production. Therefore, we would like to review the characteristics of MUC2 and its role in intestinal disorders and highlight the importance of further studies. We also investigated whether the role of MUC2 differs between children and adults, ulcerative colitis (UC) and Crohn's disease (CD).

Effect of 2,6-xylidine (DMA) on secretion of biomarkers for inflammation and neurodevelopment by the placenta.

Cigarette smoke enhances placental inflammation and interferes with steroidogenesis. However, the chemicals in the smoke responsible for these biological activities are unclear. 2,6 xylidine (also called 2,6 Dimethylaniline, DMA) is a component of cigarette smoke that has carcinogenic properties but its effects on the placenta are unknown. Therefore, we hypothesized that DMA may interfere with placental steroidogenesis or enhance placental inflammation. Placental explant cultures were treated with 0-50,000 nM DMA and concentrations of progesterone (P4), estradiol (E2), testosterone (T), IL-1ß, TNF-α, IL-6, sgp130, HO-1, IL-10, 8-Isoprostane (8-IsoP), and BDNF in the conditioned medium were quantified. Since many environmental toxins enhance the proinflammatory host response to infection, we also performed experiments on placental cultures co-stimulated with 107 heat-killed E. coli. DMA alone significantly reduced P4 and T secretion but enhanced E2 secretion. The toxin also reduced placental secretion of IL-6, sgp130, and BDNF. For bacteria-stimulated cultures, DMA increased secretion of P4 and T, and proinflammatory cytokines (IL-1ß, TNF-α) but had mixed effects on anti-inflammatory markers, increasing some (sgp130, IL-10) and reducing others (HO-1). However, DMA enhanced 8-IsoP levels by bacteria-stimulated placental cultures, suggesting that it increases oxidative stress by the tissues. These studies suggest that DMA affects secretion of biomarkers by the placenta and may promote inflammation. Further studies are needed to determine if these observed changes occur in vivo and the extent to which DMA exposure increases the risk of adverse pregnancy outcomes associated with smoking in pregnancy.