Isocitrate dehydrogenase 1 upregulation in urinary extracellular vesicles from proximal tubules of type 2 diabetic rats.

Diabetic nephropathy (DN) is a major cause of chronic kidney disease. Microalbuminuria is currently the most common non-invasive biomarker for the early diagnosis of DN. However, renal structural damage may have advanced when albuminuria is detected. In this study, we sought biomarkers for early DN diagnosis through proteomic analysis of urinary extracellular vesicles (uEVs) from type 2 diabetic model rats and normal controls. Isocitrate dehydrogenase 1 (IDH1) was significantly increased in uEVs from diabetic model rats at the early stage despite minimal differences in albuminuria between the groups. Calorie restriction significantly suppressed the increase in IDH1 in uEVs and 24-hour urinary albumin excretion, suggesting that the increase in IDH1 in uEVs was associated with the progression of DN. Additionally, we investigated the origin of IDH1-containing uEVs based on their surface sugar chains. Lectin affinity enrichment and immunohistochemical staining showed that IDH1-containing uEVs were derived from proximal tubules. These findings suggest that the increase in IDH1 in uEVs reflects pathophysiological alterations in the proximal tubules and that IDH1 in uEVs may serve as a potential biomarker of DN in the proximal tubules.

The 5-lipoxygenase/cyclooxygenase-2 cross-over metabolite, hemiketal E2, enhances VEGFR2 activation and promotes angiogenesis.

Consecutive oxygenation of arachidonic acid by 5-lipoxygenase and cyclooxygenase-2 yields the hemiketal eicosanoids, HKE2 and HKD2. Hemiketals stimulate angiogenesis by inducing endothelial cell tubulogenesis in culture; however, how this process is regulated has not been determined. Here, we identify vascular endothelial growth factor receptor 2 (VEGFR2) as a mediator of HKE2-induced angiogenesis in vitro and in vivo. We found that HKE2 treatment of human umbilical vein endothelial cells dose-dependently increased the phosphorylation of VEGFR2 and the downstream kinases ERK and Akt that mediated endothelial cell tubulogenesis. In vivo, HKE2 induced the growth of blood vessels into polyacetal sponges implanted in mice. HKE2-mediated effects in vitro and in vivo were blocked by the VEGFR2 inhibitor vatalanib, indicating that the pro-angiogenic effect of HKE2 was mediated by VEGFR2. HKE2 covalently bound and inhibited PTP1B, a protein tyrosine phosphatase that dephosphorylates VEGFR2, thereby providing a possible molecular mechanism for how HKE2 induced pro-angiogenic signaling. In summary, our studies indicate that biosynthetic cross-over of the 5-lipoxygenase and cyclooxygenase-2 pathways gives rise to a potent lipid autacoid that regulates endothelial cell function in vitro and in vivo. These findings suggest that common drugs targeting the arachidonic acid pathway could prove useful in antiangiogenic therapy.

Seabuckthorn (Hippophae rhamnoides, L.) pulp oil prevents ultraviolet-induced damage in human fibroblasts.

Seabuckthorn pulp oil (SBO) is used in beauty products because of its rich lipophilic substances with high nutraceutical and cosmeceutical potential. However, the mechanism through which SBO enhances skin elasticity remains unclear. Therefore, in this study, we examined the anti-photoaging activity of SBO in normal human dermal fibroblasts (NHDF) under ultraviolet (UV) irradiation. Pretreatment with SBO significantly suppressed UV-B-induced cell toxicity and collagen degradation, suggesting that SBO contains anti-photoaging substances. Further, palmitoleic acid (POA), the main component of SBO, maintained cell viability and collagen levels in UV-B-irradiated NHDF by suppressing the expression of matrix metalloproteinase 1 (MMP-1) and acted on the inhibition of p38 and JNK phosphorylation and nuclear translocation of nuclear factor-kappa B (NF-κB). These findings suggest the utility of SBO as an anti-photoaging agent.

Neuritogenic steroid glycosides from crown-of-thorns starfish: Possible involvement of p38 mitogen-activated protein kinase and attenuation of cognitive impairment in senescence-accelerated mice (SAMP8) by peripheral administration.

Novel steroid glycosides, acanthasterosides A1, B1, and B3, have been isolated from the crown-of-thorns starfish Acanthaster planci. Acanthasterosides B1 and B3 having two separated xyloses induced neurite outgrowth as like as nerve growth factor (NGF) in the rat pheochromocytoma cell line PC12, whereas acanthasteroside A1, having one xylose, did not induce neurite outgrowth. The acanthasteroside B3 induced neuritogenesis via the significant activation of p38 mitogen-activated protein kinase after the activation of the small G-protein Cdc42 rather than via Ras-MEK-ERK pathway that is predominantly activated by NGF. Following subcutaneous administration, acanthasteroside B3 attenuated cognitive impairment of senescence-accelerated mice (SAMP8) in two different cognitive tests. Liquid chromatography-mass spectrometry-assisted quantitative analysis demonstrated that acanthasteroside B3 could be transported into the brain via the circulatory system in mice. Thus, acanthasteroside B3 (and possibly B1) are a novel class of potential drug candidates for neurodegenerative diseases.

The sarcopenia index measured using the lumbar paraspinal muscle is associated with prognosis in endometrial cancer.

OBJECTIVE: The number of type-II endometrial cancer patients has been increasing and the prognosis is not favorable. We aim to investigate whether sarcopenia index in any of several different muscles could serve as a novel biomarker of prognosis in patients with type-II endometrial cancer. METHODS: We retrospectively investigated a total of 194 patients at four hospitals. Ninety patients were treated as derivation set and the other 104 patients as validation set. Using preoperative computed tomography images, we measured the horizontal cross-sectional area at the third lumbar spine level: the (i) psoas major, (ii) iliac and (iii) paraspinal muscle. The clinical information including recurrence-free survival and overall survival were retrospectively collected. These results were validated with external data sets of three hospitals. RESULTS: The median values of the sarcopenia index (cm2/m2) ± standard deviation with the first data of 90 patients using the psoas, iliac and paraspinal muscle were 3.4 ± 1.0, 1.7 ± 0.6 and 12.6 ± 3.2, respectively. In univariate analyses, the sarcopenia indexes measured using the psoas or paraspinal muscle were associated with recurrence-free survival and overall survival. On the other hand, in multivariate analyses, only the sarcopenia index using paraspinal muscle was significantly related to recurrence-free survival (hazard ratio = 3.78, 95% confidence intervals = 1.29-5.97, P = 0.009) and overall survival (hazard ratio = 3.13, 95% confidence interval = 1.18-8.26, P = 0.022). Paraspinal sarcopenia index was also related to overall survival (hazard ratio = 3.74, 95% confidence interval = 1.31-10.72, P = 0.014) even in patients with advanced stage. Serum albumin was significantly correlated with the sarcopenia index (P = 0.012). Within the analysis of the validation set, sarcopenia index using paraspinal muscle was related to recurrence-free survival (hazard ratio = 2.06, P = 0.045) in multivariate analysis and recurrence-free survival (P = 0.009) in patients with advanced stage. CONCLUSIONS: The sarcopenia index using the paraspinal muscle, not psoas, could be a suitable index to predict recurrence-free survival and overall survival in patients with type-II endometrial cancer even in advanced stage.

Eriodictyol and thymonin act as GPR35 agonists.

Although herbs and spices have been used in traditional medicine for more than a century owing to their health benefits, the associated underlying mechanism is still not clear. Since the G protein-coupled receptor 35 (GPR35) has been linked to exert various antioxidant and anti-inflammatory effects, we screened 19 different herbs and spices for possible GPR35 agonist(s) to understand the GPR35-dependent functions of herbs and spices. Among the screened extracts, the ethyl acetate extract of thyme exhibited a remarkable GPR35 agonistic activity. Activity-guided separations allowed us to identify 2 polyphenolic phytochemicals, eriodictyol and thymonin, acting as GPR35 agonists. Both eriodictyol and thymonin showed a potent and specific agonist activity toward GPR35 with half maximal effective concentration values of 5.48 and 8.41 µm, respectively. These findings indicate that these phytochemicals may have beneficial health effects upon GPR35 activation.

A Review of Treatment Methods Focusing on Human Induced Pluripotent Stem Cell-Derived Neural Stem/Progenitor Cell Transplantation for Chronic Spinal Cord Injury.

Cell transplantation therapy using human induced pluripotent stem cell-derived neural stem/progenitor cells (hiPSC-NS/PCs) has attracted attention as a regenerative therapy for spinal cord injury (SCI), and its efficacy in treating the subacute phase of SCI has been reported in numerous studies. However, few studies have focused on treatment in the chronic phase, which accounts for many patients, suggesting that there are factors that are difficult to overcome in the treatment of chronic SCI. The search for therapeutic strategies that focus on chronic SCI is fraught with challenges, and the combination of different therapies is thought to be the key to a solution. In addition, many issues remain to be addressed, including the investigation of therapeutic approaches for more severe injury models of chronic SCI and the acquisition of practical motor function. This review summarizes the current progress in regenerative therapy for SCI and discusses the prospects for regenerative medicine, particularly in animal models of chronic SCI.

[Peritoneal Mesothelioma Diagnosed with a Sister Mary Joseph's Nodule].

In August 2022, a 59-year-old female noted a mass in her umbilicus and sought evaluation at Toyokawa City Hospital. Abdominal computed tomography(CT)scan revealed a 1.6 cm mass in the umbilical region, ascites in the pelvis, and increased absorption in the omentum. Peritoneal dissemination of the carcinoma and Sister Mary Joseph's nodule due to an unknown primary tumor were suspected because no abnormalities were detected during upper and lower gastrointestinal endoscopy. She underwent an umbilical lumpectomy and diagnostic laparoscopy to establish a definitive diagnosis. The surgical findings included numerous white nodules throughout the abdominal cavity. The umbilical mass and omental white nodules were resected. A final diagnosis of epithelial peritoneal mesothelioma was made based on the histopathologic examination. In general, peritoneal mesothelioma has a poor prognosis, and early treatment is essential; however, making a timely definitive diagnosis is difficult. Peritoneal mesothelioma should be included in the differential diagnosis for a patient with unexplained ascites and abdominal pain. Diagnostic laparoscopy and biopsy will facilitate the establishment of a definitive diagnosis.

Oxidative deamination of lysine residues by polyphenols generates an equilibrium of aldehyde and 2-piperidinol products.

Polyphenols, especially catechol-type polyphenols, exhibit lysyl oxidase-like activity and mediate oxidative deamination of lysine residues in proteins. Previous studies have shown that polyphenol-mediated oxidative deamination of lysine residues can be associated with altered electrical properties of proteins and increased crossreactivity with natural immunoglobulin M antibodies. This interaction suggested that oxidized proteins could act as innate antigens and elicit an innate immune response. However, the structural basis for oxidatively deaminated lysine residues remains unclear. In the present study, to establish the chemistry of lysine oxidation, we characterized oxidation products obtained via incubation of the lysine analog N-biotinyl-5-aminopentylamine with eggshell membranes containing lysyl oxidase and identified a unique six-membered ring 2-piperidinol derivative equilibrated with a ring-open product (aldehyde) as the major product. By monitoring these aldehyde-2-piperidinol products, we evaluated the lysyl oxidase-like activity of polyphenols. We also observed that this reaction was mediated by some polyphenols, especially o-diphenolic-type polyphenols, in the presence of copper ions. Interestingly, the natural immunoglobulin M monoclonal antibody recognized these aldehyde-2-piperidinol products as an innate epitope. These findings establish the existence of a dynamic equilibrium of oxidized lysine and provide important insights into the chemopreventive function of dietary polyphenols for chronic diseases.

Rapid Isolation of Extracellular Vesicles Using a Hydrophilic Porous Silica Gel-Based Size-Exclusion Chromatography Column.

Extracellular vesicles (EVs) are nanoscale lipid bilayer vesicles released by almost all cell types and can be found in biological fluids, such as blood and urine. EVs play an important role in various physiological and pathological processes via cell-cell communication, highlighting their potential applications as diagnostic markers for diseases and therapeutic drug delivery carriers. Although various methods have been developed for the isolation of EVs from biological fluids, most of them exhibit major limitations, including low purity, long processing times, and high cost. In this study, we developed a size-exclusion chromatography (SEC) column device using hydrophilic porous silica gel (PSG). Owing to the resistance to pressure of the device, a rapid system for EV isolation was developed by connecting it to a flash liquid chromatography system furnished with a UV detector and a fraction collector. This system can be used for the real-time monitoring of eluted EVs by UV absorption without further analysis and separation of high-purity EVs from urine samples with high durability, reusability, and reproducibility. In addition, there were no significant differences between the PSG column- and conventional SEC column-isolated EVs in the proteome profiles and cellular uptake activities, suggesting the good quality of the EVs isolated by the PSG column. These findings suggest that the PSG column device offers an effective and rapid method for the isolation of intact EVs from biological fluids.

Glycolaldehyde is an endogenous source of lysine N-pyrrolation.

Lysine N-pyrrolation converts lysine residues to Nϵ-pyrrole-l-lysine (pyrK) in a covalent modification reaction that significantly affects the chemical properties of proteins, causing them to mimic DNA. pyrK in proteins has been detected in vivo, indicating that pyrrolation occurs as an endogenous reaction. However, the source of pyrK remains unknown. In this study, on the basis of our observation in vitro that pyrK is present in oxidized low-density lipoprotein and in modified proteins with oxidized polyunsaturated fatty acids, we used LC-electrospray ionization-MS/MS coupled with a stable isotope dilution method to perform activity-guided separation of active molecules in oxidized lipids and identified glycolaldehyde (GA) as a pyrK source. The results from mechanistic experiments to study GA-mediated lysine N-pyrrolation suggested that the reactions might include GA oxidation, generating the dialdehyde glyoxal, followed by condensation reactions of lysine amino groups with GA and glyoxal. We also studied the functional significance of GA-mediated lysine N-pyrrolation in proteins and found that GA-modified proteins are recognized by apolipoprotein E, a binding target of pyrrolated proteins. Moreover, GA-modified proteins triggered an immune response to pyrrolated proteins, and monoclonal antibodies generated from mice immunized with GA-modified proteins specifically recognized pyrrolated proteins. These findings reveal that GA is an endogenous source of DNA-mimicking pyrrolated proteins and may provide mechanistic insights relevant for innate and autoimmune responses associated with glucose metabolism and oxidative stress.

Screening of a novel free fatty acid receptor 1 (FFAR1) agonist peptide by phage display and machine learning based-amino acid substitution.

Free fatty acid receptor 1 (FFAR1 or GPR40) has attracted attention for the treatment of type 2 diabetes mellitus, and various small-molecule agonists have been developed. However, most FFAR1 agonists as well as endogenous ligands, such as linoleic acids, have high lipophilicity, and their high lipophilicity is related to off-target toxicity. Therefore, we need to focus on new ligand candidates with less toxicity. In this study, we screened peptides with FFAR1 agonist activity as new ligand candidates. First, we used phage display to identify peptides with high affinity to FFAR1. Next, the agonist activities of peptides determined by the phage display were evaluated by the TGF-α shedding assay. Finally, to improve the FFAR1 agonist activity of the peptide, we performed an inclusive single amino acid substitution and sequence analysis. Logistic regression (LR) analysis using 120 physiochemical properties was performed to predict peptides with high FFAR1 agonist activity. STTGTQY determined by phage display promoted glucose-stimulated insulin secretion in pancreatic MIN6 cells. Furthermore, STKGTF predicted by the LR analysis showed high insulin secretion at low concentrations compared to STTGTQY. The results of this study suggest that peptides could be new candidates as FFAR1 agonists.

Low-molecular-weight whey proteins promote collagen production in dermal fibroblasts via the TGF-ß receptor/Smad pathway.

Whey proteins (WPs) reportedly enhance cutaneous tissue regeneration in in vivo studies. However, the underlying mechanisms of such regenerative processes are poorly understood. In this study, we show that low-molecular-weight WPs (LMWPs; 1-30 kDa) accelerate the dermal collagen production via the transforming growth factor ß receptor (TßR)/Smad pathway. We showed that LMWPs increased type I and III collagen expression in normal human dermal fibroblasts. Moreover, LMWPs rapidly induced Smad protein phosphorylation and nuclear translocation. Notably, type I TßR/Smad signaling inhibitor treatment or type II TßR siRNA knockdown blocked the LMWP-induced type I collagen expression. To identify the active components, we fractionated LMWPs and identified ß-lactoglobulin and α-lactalbumin as potential TßR/Smad signaling inducers. Our findings unravel novel biological functions of WPs, involving the TßR/Smad-dependent induction of dermal collagen synthesis, highlighting the therapeutic potential of LMWPs in wound healing.

Identification of biosynthetic intermediates for the mating hormone α2 of the plant pathogen Phytophthora.

The heterothallic group of the plant pathogen Phytophthora can sexually reproduce between the cross-compatible mating types A1 and A2. The mating hormone α2, produced by A2 mating type and utilized to promote the sexual reproduction of the partner A1 type, is known to be biosynthesized from phytol. In this study, we identified 2 biosynthetic intermediates, 11- and 16-hydroxyphytols (1 and 2), for α2 by administering the synthetic intermediates to an A2-type strain to produce α2 and by administering phytol to A2 strains to detect the intermediates in the mycelia. The results suggest that α2 is biosynthesized by possibly 2 cytochrome P450 oxygenases via 2 hydroxyphytol intermediates (1 and 2) in A2 hyphae and secreted outside.

[A Case of Rectal Cancer with Lymph Node Metastasis Diagnosed as Intramucosal Cancer].

The patient was a 62-year-old man in whom 0-Ⅱa plus Ⅱc lesions in Rs were identified during follow-up observation of multiple colorectal polyps that were found during colonoscopy performed for the examination of fecal occult blood. CT showed no lymphadenopathy or distant metastasis to other organs. Laparoscopic-assisted high anterior resection of the rectum was performed with a diagnosis of clinical stage Ⅰ. Pathologically, there was a well-to-moderately differentiated tubular adenocarcinoma that remained in the lamina propria; however, 1 metastasis was found in the lymph node adjacent to the rectum(#251). Therefore, adjuvant chemotherapy was performed for 6 months after the operation, and 5 years have passed with no recurrence. Here, we report a case with no apparent submucosal invasion but with lymph node metastasis. We confirm recurrence-free survival for 5 years after surgery.

2-Oxo-histidine-containing dipeptides are functional oxidation products.

Imidazole-containing dipeptides (IDPs), such as carnosine and anserine, are found exclusively in various animal tissues, especially in the skeletal muscles and nerves. IDPs have antioxidant activity because of their metal-chelating and free radical-scavenging properties. However, the underlying mechanisms that would fully explain IDP antioxidant effects remain obscure. Here, using HPLC-electrospray ionization-tandem MS analyses, we comprehensively investigated carnosine and its related small peptides in the soluble fractions of mouse tissue homogenates and ubiquitously detected 2-oxo-histidine-containing dipeptides (2-oxo-IDPs) in all examined tissues. We noted enhanced production of the 2-oxo-IDPs in the brain of a mouse model of sepsis-associated encephalopathy. Moreover, in SH-SY5Y human neuroblastoma cells stably expressing carnosine synthase, H2O2 exposure resulted in the intracellular production of 2-oxo-carnosine, which was associated with significant inhibition of the H2O2 cytotoxicity. Notably, 2-oxo-carnosine showed a better antioxidant activity than endogenous antioxidants such as GSH and ascorbate. Mechanistic studies indicated that carnosine monooxygenation is mediated through the formation of a histidyl-imidazole radical, followed by the addition of molecular oxygen. Our findings reveal that 2-oxo-IDPs are metal-catalyzed oxidation products present in vivo and provide a revised paradigm for understanding the antioxidant effects of the IDPs.

Apolipoprotein E binds to and reduces serum levels of DNA-mimicking, pyrrolated proteins.

Lysine N-pyrrolation, converting lysine residues to Nϵ-pyrrole-l-lysine, is a recently discovered post-translational modification. This naturally occurring reaction confers electrochemical properties onto proteins that potentially produce an electrical mimic to DNA and result in specificity toward DNA-binding molecules such as anti-DNA autoantibodies. The discovery of this unique covalent protein modification provides a rationale for establishing the molecular mechanism and broad functional significance of the formation and regulation of Nϵ-pyrrole-l-lysine-containing proteins. In this study, we used microbeads coupled to pyrrolated or nonpyrrolated protein to screen for binding activities of human serum-resident nonimmunoglobin proteins to the pyrrolated proteins. This screen identified apolipoprotein E (apoE) as a protein that innately binds the DNA-mimicking proteins in serum. Using an array of biochemical assays, we observed that the pyrrolated proteins bind to the N-terminal domain of apoE and that oligomeric apoE binds these proteins better than does monomeric apoE. Employing surface plasmon resonance and confocal microscopy, we further observed that apoE deficiency leads to significant accumulation of pyrrolated serum albumin and is associated with an enhanced immune response. These results, along with the observation that apoE facilitates the binding of pyrrolated proteins to cells, suggest that apoE may contribute to the clearance of pyrrolated serum proteins. Our findings uncover apoE as a binding target of pyrrolated proteins, providing a key link connecting covalent protein modification, lipoprotein metabolism, and innate immunity.

Relationship among structure, cytotoxicity, and Michael acceptor reactivity of quinocidin.

Quinocidin (QCD) is a cytotoxic antibiotic with an unusual 3,4-dihydroquinolizinium skeleton. We previously found that QCD captures thiols in neutral aqueous media via a Michael addition-type reaction. However, it remains unclear whether the Michael acceptor reactivity of QCD is responsible for its cytotoxicity. In this study, we synthesized thirteen analogs of QCD to examine the relationship among its structure, cytotoxicity, and reactivity toward thiols. Thiol-trapping experiments and cytotoxicity tests collectively suggested that the Michael acceptor function of QCD is independent of its cytotoxic activity, and that the pyridinium moiety with the hydrophobic side chain is a key structural factor for cytotoxicity. These findings further led us to demonstrate that incorporation of an amide group into the side chain of QCD significantly reduced its toxicity but hardly affected the Michael acceptor function. The present study lays the foundation for QCD-based drug design and highlights the potential of QCD as a unique electrophile for use in the development of covalent inhibitors and protein-labeling probes.

Time-lapse imaging of Ca2+-induced swelling and permeability transition: Single mitochondrion study.

Mitochondrial functions are closely related to the membrane structure. Mitochondrial swelling, which is accompanied with dissipation of the crista structure and rupture of the outer membrane, have been observed as mitochondrial damage when mitochondria are under Ca2+-overload or oxidative stress. Although these phenomena have been well studied, the detailed behaviors of individual mitochondria upon swelling remain unknown. The aim of this study was to investigate the detailed behavior of mitochondrial volume upon addition of Ca2+. Here, we report for the first time, time-lapse measurements of single mitochondrion swelling and permeability transition induced by Ca2+ by optical microscopy. We added 220 µM Ca2+ to mitochondria, and found that 1) the swelling rate depended on the mitochondrion, 2) a small number of mitochondria showed step-like swelling, 3) cyclosporin A decreased the percentage of mitochondria that underwent swelling induced by Ca2+, but did not affect the amplitude of swelling, 4) permeability transition is necessary but not sufficient for Ca2+-induced swelling, 5) permeability transition is more sensitive to Ca2+ than swelling, 6) Ca2+ stimulated mitochondrial swelling after permeability transition. These results suggest that single mitochondrion measurement of swelling is a powerful tool for examining the regulation of mitochondrial structure.

[A Case of Colostomy-Free and Long-Term Survival with 5-FU/CDDP for Local Recurrence of Anal Cancer after Chemoradiation Therapy].

We report a case of colostomy-free, long-term survival following 5-FU/CDDP for the local recurrence of anal cancer after chemoradiation therapy(CRT). The patient was a 48-year-old woman who was diagnosed with cStage ⅢA anal cancer. She was treated with CRT(5-FU/MMC plus 59 Gy)and achieved a complete response upon treatment completion. A local recurrence was detected on the left-side wall of her rectum after 6 months. We recommended abdominoperineal resection but the patient refused operation. The patient was treated with chemotherapy consisting of 5-FU(1,000mg/m / 2/day)on days 1-5 and CDDP(100mg/m / 2/day)on day 2. Grade 3 peripheral neuropathy appeared following the completion of 5 courses. Therefore, the dose was reduced to 60%. Twenty-five courses of this treatment were continued and chemotherapy was completed. The patient has been alive with no sign of recurrence for 6 years and 8 months from the initial treatment. CRT for anal cancer is becoming a standard therapy but local recurrence is possible. In these cases, abdominoperineal resection is required. Chemotherapy with 5-FU/CDDP in cases of recurrence can be a colostomy-free option.