Carnosine dipeptidase II (CNDP2) protects cells under cysteine insufficiency by hydrolyzing glutathione-related peptides.

The knockout (KO) of the cystine transporter xCT causes ferroptosis, a type of iron-dependent necrotic cell death, in mouse embryonic fibroblasts, but this does not occur in macrophages. In this study, we explored the gene that supports cell survival under a xCT deficiency using a proteomics approach. Analysis of macrophage-derived peptides that were tagged with iTRAQ by liquid chromatography-mass spectrometry revealed a robust elevation in the levels of carnosine dipeptidase II (CNDP2) in xCT KO macrophages. The elevation in the CNDP2 protein levels was confirmed by immunoblot analyses and this elevation was accompanied by an increase in hydrolytic activity towards cysteinylglycine, the intermediate degradation product of glutathione after the removal of the γ-glutamyl group, in xCT KO macrophages. Supplementation of the cystine-free media of Hepa1-6 cells with glutathione or cysteinylglycine extended their survival, whereas the inclusion of bestatin, an inhibitor of CNDP2, counteracted the effects of these compounds. We established CNDP2 KO mice by means of the CRISPR/Cas9 system and found a decrease in dipeptidase activity in the liver, kidney, and brain. An acetaminophen overdose (350 mg/kg) showed not only aggravated hepatic damage but also renal injury in the CNDP2 KO mice, which was not evident in the wild-type mice that were receiving the same dose. The aggravated renal damage in the CNDP2 KO mice was consistent with the presence of abundant levels of CNDP2 in the kidney, the organ prone to developing ferroptosis. These collective data imply that cytosolic CNDP2, in conjugation with the removal of the γ-glutamyl group, recruits Cys from extracellular GSH and supports redox homeostasis of cells, particularly in epithelial cells of proximal tubules that are continuously exposed to oxidative insult from metabolic wastes that are produced in the body.

Anti-Alzheimer's flavanolignans from Ceiba pentandra aerial parts.

Four flavanolignans, ceibapentains A (1) and B (2) and cinchonains Ia (3) and Ib (4), were isolated for the first time from an ethyl acetate extract of Ceiba pentandra (L) (Bombacaceae) aerial parts. The ceibapentains A (1) and B (2) are new compounds and their structures, including the absolute configurations, were determined by HRESIMS, 1D and 2D NMR, and electronic circular dichroism analyses, then compared with reported data. Compounds 1-4 were tested for their anti-Alzheimer's activity via an assessment of their inhibitory effect on amyloid ß42 aggregation using a thioflavin T assay. The results revealed that cinchonain Ia (3) showed a higher inhibitory effect (91%) than the standard curcumin (70%). Compounds 1, 2, and 4 exhibited moderate activity, with inhibition ratios of 43%, 47%, and 58%, respectively. A molecular docking study on the binding mode of 3 and curcumin with an amyloid ß1-40 peptide fibril structure indicated a high affinity of cinchonain 1a (3) towards amyloid ß1-40 peptide, in agreement with the experimental results.

Synthesis of ß-Hydroxytyrosine, A Component of Burkholdines.

The preparation of four stereoisomers of ß-hydroxytyrosine containing burkholdines is described. Enantio-pure syn ß-hydroxytyrosine was synthesized using Sharpless aminohydroxylation. To obtain anti ß-hydroxytyrosine, the cinnamate derivative was oxidized to give the optical active diol derivative by the AD-mix and subsequently, the a-hydroxy group was converted to amine. Deprotection of the acid-sensitive ß-hydroxytyrosine derivatives was successively accomplished by brief immersion in 4N HCl/dioxane. All prepared stereoisomers of ß-hydroxytyrosine were available for solid and solution phase peptide synthesis and amino acid analysis.

Utility of a preloaded fenestrated graft in thoracoabdominal aneurysm repair.

An 84-year-old man with a thoracoabdominal aortic aneurysm was treated using a fenestrated stent graft with a preloaded guidewire system under local anesthesia. He suffered from severe chronic obstructive pulmonary disease. We successfully placed 4 bridging stent grafts for perfusion of the celiac artery, superior mesenteric artery, and bilateral renal arteries via the 4 fenestrations. A preloaded wire system was used to insert a catheter into the celiac artery from the left brachial artery. Our findings indicate that a fenestrated stent graft with a preloaded wire system may expand the indication for treating thoracoabdominal aortic aneurysms in high-risk patients.

Melinjo (Gnetum gnemon L.) Seed Extract Decreases Serum Uric Acid Levels in Nonobese Japanese Males: A Randomized Controlled Study.

Melinjo (Gnetum gnemon L.) seed extract (MSE) containing trans-resveratrol (3,5,4'-trihydroxy-trans-stilbene) and other derivatives exerts various beneficial effects. However, its mechanism of action in humans remains unknown. In this study, we aimed to investigate beneficial effects of MSE in healthy adult males. In this double-blind, randomized controlled study, 30 males aged 35-70 years with ≤10% flow-mediated dilatation received placebo or 750 mg MSE powder for 8 weeks, and twenty-nine males (45.1 ± 8.8 years old) completed the trial. There was a significant difference in the melinjo and placebo groups. Compared with the placebo control, MSE significantly reduced serum uric acid at 4 weeks and 8 weeks (n = 14 and 15, resp.). HDL cholesterol was significantly increased in the melinjo group. To clarify the mechanism of MSE for reducing uric acid, we investigated xanthine oxidase inhibitory activity, angiotensin II type 1 (AT1) receptor binding inhibition rate, and agonistic activities for PPAR α and PPAR γ . MSE, trans-resveratrol, and a resveratrol dimer, gnetin C (GC), significantly inhibit AT1 receptor binding and exhibit mild agonistic activities for PPAR α and PPAR γ . In conclusion, MSE may decrease serum uric acid regardless of insulin resistance and may improve lipid metabolism by increasing HDL cholesterol.

Pancreatic neuroendocrine cell tumor secreting parathyroid hormone-related protein and gastrin: Report of a case.

This report presents a case of pancreatic neuroendocrine cell carcinoma with multiple liver metastases secreting gastrin and parathyroid hormone-related protein (PTHrP) related to lumbar bone fracture and hypercalcemia. A 58-year-old woman visited an affiliated hospital with a chief complaint of lumbago without any evidence of trauma. She was diagnosed with hepatic dysfunction and hypercalcemia as well as multiple lumbar compression fractures without osteolytic lesions. Abdominal computed tomography (CT) showed a hypervascular mass in the pancreatic tail and multiple liver tumors. Duodenal ulcers were found with gastrointestinal endoscopy. There was a marked increase in the serum gastrin level. She was diagnosed as gastrinoma with multiple liver metastases and was admitted to the hospital. She had an increase in serum PTHrP level without the elevation of intact parathyroid hormone at the time of admission. She underwent an extended right hepatectomy in addition to a distal pancreatectomy with a regional lymphadenectomy and splenectomy. The postoperative course was uneventful, and serum gastrin and PTHrP activities reduced to normal levels. She remained symptom-free, and serum calcium, gastrin, and PTHrP levels remain within the normal ranges 19 months after surgery without adjuvant therapy.

Current clinical strategy for imatinib-resistant gastrointestinal stromal tumors.

Before the advent of imatinib, no effective agent was available for the treatment of unresectable or metastatic gastrointestinal stromal tumors (GISTs). However, the treatment strategy changed and the prognosis of patients with advanced or recurrent GIST improved remarkably after the development of imatinib. Despite the high rate of clinical benefit of imatinib in GIST patients, more than half of GIST patients eventually develop primary or secondary resistance to imatinib, resulting in the progression of the disease. It has also been reported that about 5% of patients are intolerant to imatinib. An effective treatment strategy for imatinib-resistant GIST is needed. The National Comprehensive Cancer Network guidelines recommend a multidisciplinary approach, but the therapeutic modalities are still limited, and none are able to achieve complete remission. In this review, we summarize the current understandings of the mechanism of imatinib resistance and the clinical strategies used against imatinib-resistant GIST, including surgical intervention, escalation of imatinib dose, and use of sunitinib or other agents. Understanding these issues may help in the development of a new treatment paradigm for GIST patients.

Intraperitoneal administration of hyperbarically oxygenated perfluorochemical enhances preservation of intestinal mucosa against ischemia/reperfusion injury.

Perfluorochemicals (PFCs) have a high solubility for oxygen. We have previously demonstrated the effect of peritoneal lavage with oxygenated PFC (O2-PFC) on ameliorating ischemia/reperfusion (I/R)-induced intestinal ischemic damage in an animal model. In this study, we applied hyperbarically O2-PFC (HBO-PFC) to investigate whether a larger amount of oxygen carried by PFC could enhance the protective effect of O2-PFC during intestinal malperfusion. Rats were subjected to ischemia by clamping the superior mesenteric artery (SMA) for 90 min. The SMA was then declamped. Rats were divided into four groups. In group A, only anesthesia and abdominal incision were performed. In group B, SMA was clamped without O2-PFC. In group C, during the SMA clamp, 1 atm O2-PFC was injected into the abdominal cavity. In group D, 5 atm O2-PFC (HBO-PFC) was prepared using a custom-made hyperbaric oxygen tank and administered to the abdominal cavity during the SMA clamp. Ileal tissue adenosine triphosphate (ATP) levels 90 min after SMA declamping were determined using luciferase assay. To assess intestinal mucosal barrier function at 90 min after release of the SMA clip, everted gut sacs were prepared to measure the mucosal-to-serosal passage of fluorescein-conjugated dextran (FD4, molecular weight = 4 kDa). Thirty minutes after i.p. administration, partial pressure of oxygen in HBO-PFC remained around 1000 mmHg, whereas partial pressure of oxygen in 1 atm O2-PFC decreased to around 400 mmHg. The intestinal tissue ATP was significantly preserved in group D. Moreover, the mucosal hyperpermeability of the gut sac after I/R was significantly ameliorated in group D. Hyperbarically oxygenated perfluorochemical might supply a larger amount of oxygen to ischemic tissue during SMA clamp, which protected the small intestine from I/R injury, possibly caused by the maintenance of tissue ATP levels during ischemia.