Eugeniin improves cholesterol metabolism in HepG2 cells and Caco-2 cells

Considering the absence of prior studies on the cholesterol metabolism-improving effects of eugeniin, the present investigation aimed to explore the potential impact of eugeniin on cholesterol metabolism. This study sought to elucidate the molecular mechanisms involved in this process using HepG2 and Caco-2 cells treated with 5 µm eugeniin. The intracellular cholesterol levels in HepG2 and Caco-2 cells were significantly decreased in the 24-h eugeniin-treated group. The protein and messenger ribonucleic acid (mRNA) levels of the low-density lipoprotein receptor (LDLR) were increased, while 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase protein and mRNA levels were decreased in HepG2 cells 6 h of the eugeniin-treated group. Additionally, LDLR protein and mRNA levels were increased in HepG2 cells after 24 h of eugeniin treatment. In Caco-2, the protein and mRNA levels of ATP-binding cassette transporter 1 were increased after 24 h eugeniin treatment. This novel finding indicates that eugeniin improves cholesterol metabolism in human cell cultures.

[A Case of Achieving CR through Chemoradiotherapy for Postoperative Oligo Lymph Node Metastasis in Gastric Cancer]

We present a case of oligo lymph node metastasis in a 70s man who had previously undergone subtotal gastrectomy for advanced gastric cancer in the prepylorus. Postoperatively, adjuvant chemotherapy was administered for a duration of 1 year. During the third postoperative year, elevated tumor markers and lymph node enlargement prompted a diagnosis of lymph node metastasis. Subsequent chemoradiotherapy resulted in a complete response(CR), which has been sustained for 2 years without any recurrence. The outcomes of this case indicate that chemoradiotherapy stands as a viable treatment option for oligo lymphatic recurrence in gastric cancer.

Rose polyphenols exert antiobesity effect in high-fat-induced obese mice by regulating lipogenic gene expression

Obesity presents a major risk factor in the development of cardiovascular diseases. Recent reports indicate that many kinds of polyphenols have the potential to prevent metabolic diseases. We hypothesized that rose polyphenols (ROSE) have the effect of improvement in lipid metabolism. In this study, we investigated whether rose polyphenols affected lipid metabolism and exerted antiobesity. To clarify the mechanism, C57BL/6J mice were fed a high-fat diet containing 0.25% ROSE for 35 days. Compared with the control group, body weight gain and adipose tissue weight in the 0.25% ROSE group were significantly decreased. Serum cholesterol and hepatic triglyceride concentrations significantly decreased, whereas fecal triglyceride was significantly increased in the 0.25% ROSE group. Liver stearoyl-CoA desaturase 1 (Scd1), 3-hydroxy-3-methylglutaryl-CoA reductase (Hmgcr), and acyl-CoA:cholesterol acyltransferase 1 (Acat1) mRNA as well as protein stearoyl-CoA desaturase 1 concentrations were significantly lower in the 0.25% ROSE group than that in the control group. The mRNA and the protein concentrations of adipose triglyceride lipase, hormone-sensitive lipase, and peroxisomal acylcoenzyme A oxidase 1 in white adipose tissue were significantly higher in the 0.25% ROSE group than that in the control group. The components in rose polyphenols were quantified by liquid chromatography-tandem mass spectrometry, and we consider that ellagic acid plays an important role in an antiobesity effect because the ellagic acid content is the highest among polyphenols in rose polyphenols. In summary, rose polyphenols exhibit antiobesity effects by influencing lipid metabolism-related genes and proteins to promote lipolysis and suppress lipid synthesis.

Pentapeptide IIAEK ameliorates cholesterol metabolism via the suppression of intestinal cholesterol absorption in mice

Dietary protein-derived peptides are effective in improving dyslipidemia and hypercholesterolemia. We previously identified a novel cholesterol-lowering pentapeptide IIAEK from milk beta-lactoglobulin. However, it remains unclear whether IIAEK affects the micellar solubility of cholesterol and the bile acid-binding ability to lower cholesterol. Moreover, there is no direct evidence that IIAEK inhibits intestinal cholesterol absorption and affects hepatic cholesterol and fecal steroid excretion in vivo. Herein, we showed that IIAEK did not affect the micellar solubility of cholesterol and the bile acid-binding ability. However, we found that IIAEK decreased serum and liver cholesterol levels and increased fecal steroid excretion in mice. Interestingly, IIAEK markedly suppressed the intestinal absorption of [3H]-cholesterol in mice. In conclusion, we found that IIAEK ameliorated cholesterol metabolism by suppressing intestinal cholesterol absorption without affecting in vitro micellar solubility of cholesterol and the bile acid-binding ability in mice.

Comparison of the slow-pull and aspiration methods of endobronchial ultrasound-guided transbronchial needle aspiration for next-generation sequencing-compatible tissue collection in non-small cell lung cancer

BACKGROUND

Personalized treatment for non-small cell lung cancer (NSCLC) has advanced rapidly, and elucidating the genetic changes that trigger this disease is crucial for appropriate treatment selection. Both slow-pull and aspiration methods of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) are accepted methods for collecting samples suitable for next-generation sequencing (NGS) to examine driver gene mutations and translocations in NSCLC. Here, we aimed to determine which of these two methods is superior for obtaining higher-quality samples from patients with NSCLC.

METHODS

Seventy-one patients diagnosed with NSCLC via EBUS-TBNA using the slow-pull or aspiration (20-mL negative pressure) methods between July 2019 and September 2022 were included. A total of 203 tissue samples from the 71 patients were fixed in formalin, embedded in paraffin, and mounted on slides. The presence of tissue cores, degree of blood contamination, and number of tumor cells were compared between the groups. The success rate of NGS, using Oncomine Dx Target Test Multi-CDx, was also compared between the groups.

RESULTS

The slow-pull method was associated with a higher yield of tissue cores, lower degree of blood contamination, and higher number of tumor cells than the aspiration method. The success rate of the NGS was also significantly higher for the slow-pull group (95%) than for the aspiration group (68%).

CONCLUSION

Overall, these findings suggest that the slow-pull method is a superior technique for EBUS-TBNA to obtain high-quality tissue samples for NGS. The slow-pull method may contribute to the identification of driver gene mutations and translocations and facilitate personalized treatment of NSCLC.

Predictors of lung injury during durvalumab maintenance therapy following concurrent chemoradiotherapy in unresectable locally advanced non-small cell lung carcinoma

BACKGROUND

Based on the results of the PACIFIC trial, maintenance with durvalumab has emerged as the standard treatment following concurrent chemoradiotherapy in patients with unresectable locally advanced non-small cell lung carcinoma (NSCLC). However, adverse events attributed to durvalumab, especially lung injuries, including immune-related adverse events, and radiation pneumonitis, are concerning. This study retrospectively investigated the factors related to lung injury in patients receiving the PACIFIC regimen.

METHODS

Patients with unresectable locally advanced NSCLC who received durvalumab maintenance therapy following concurrent chemoradiotherapy at Yokohama City University Medical Centre between July 2018 and March 2022 were included. Clinical data, volume of normal lung receiving 20 or 5 Gy or more (V20 or V5), planning target volume (PTV), and relative lung parenchyma volume in emphysematous lung receiving 20 or 5 Gy or more (RLPV20 or 5; V20 or V5/100-percentage of low-attenuation volume) were evaluated.

RESULTS

Performance status (PS), V20, V5, PTV, RLPV20, and RLPV5 were significantly higher in the lung injury group in the univariate analysis. Furthermore, RLPV20 was the most significant factor in the lung injury group in the multivariate analysis comprising PS, PTV, V20, and RLPV20.

CONCLUSION

RLPV20 and RLPV5 are useful in estimating lung inflammation. RLPV20 could be considered the most reliable risk factor for maintenance therapy with durvalumab following concurrent chemoradiotherapy in patients with unresectable locally advanced NSCLC.

Primary tracheal small-cell carcinoma detected 11 months after surgery for pulmonary large-cell neuroendocrine carcinoma: A case report

Primary tracheal small-cell carcinoma is rare, and is often treated using small-cell lung cancer guidelines given that no standard treatment has been established for it. We report a patient in whom nodules appeared in the trachea and left main bronchus 11 months after surgery for pulmonary large-cell neuroendocrine carcinoma; a biopsy revealed small-cell carcinoma. Given the absence of malignant lesions elsewhere in the body, the lesions were diagnosed as primary tracheal small-cell carcinoma. Respiratory failure progressed rapidly owing to airway stenosis caused by the growing lesion, and the patient required nasal high-flow therapy. However, the lesions shrank a few days after commencing first-line chemotherapy, and his respiratory failure resolved. Accelerated hyperfractionated radiotherapy was administered in conjunction with the third course of chemotherapy, and the patient ultimately achieved a complete response. Although the lesions were initially suspected of being postoperative recurrence of pulmonary large-cell neuroendocrine carcinoma, the fact that the biopsy revealed them to be primary tracheal small-cell carcinoma indicates that intra-airway nodules that appear after lung cancer surgery may possibly be primary tracheal tumors.

Thymic atypical carcinoid tumors with elevated mitotic counts in a patient with multiple endocrine neoplasia: A case report

Thymic neuroendocrine tumors associated with multiple endocrine neoplasia are only defined as carcinoid and are not associated with large-cell neuroendocrine carcinoma (LCNEC). We report the case of a multiple endocrine neoplasia type 1 patient with atypical carcinoid tumors with elevated mitotic counts (AC-h), an intermediate condition between carcinoid and LCNEC. A 27-year-old man underwent surgery for an anterior mediastinal mass and was diagnosed with thymic LCNEC. Fifteen years later, a mass appeared at the same site, which was determined to be a postoperative recurrence based on the pathological results of a needle biopsy and the clinical course. The patient's disease remained stable for 10 months on anti-programmed death-ligand 1 antibody and platinum-containing chemotherapy. The needle biopsy specimen was submitted for next-generation sequencing, which revealed a MEN1 gene mutation, and after further examination, a diagnosis of multiple endocrine neoplasia type 1 was made. A re-examination of the surgical specimen from 15 years prior showed that it corresponded to AC-h. Although thymic AC-h is classified as thymic LCNEC according to the current definition, our data suggests that a search for multiple endocrine neoplasia is warranted in such patients.

Protamine-derived peptide RPR (Arg-Pro-Arg) ameliorates oleic acid-induced lipogenesis via the PepT1 pathway in HepG2 cells

The protamine-derived peptide arginine-proline-arginine (RPR) can ameliorate lifestyle-related diseases such as obesity and hypercholesterolemia. Thus, we hypothesized that the hypolipidemic activity of RPR could attenuate events leading to non-alcoholic fatty liver disease. Addition of 2 m m oleic acid (OA) to the culture medium induced fatty liver conditions in HepG2 cells. The OA + RPR group showed significantly decreased cellular or medium triglyceride (TG) level compared with the OA group. Stearoyl-CoA desaturase-1 (SCD1) or sterol regulatory element-binding protein 1 (SREBP1) protein level was significantly lower in the OA + RPR group than in the OA group. In the R + P + R amino acid mixture-treated group, the TG level was not significantly different from that in the OA-treated group. The OA + RP- or OA + PR-treated groups showed significantly decreased cellular TG level compared with the OA group. Moreover, the effect of RPR disappeared when the peptide transporter 1 (PepT1) was knocked down with a siRNA. Collectively, our results demonstrated that RPR effectively ameliorated hepatic steatosis in HepG2 cells via the PepT1 pathway.

The physiological blood concentration of phenylalanine-proline can ameliorate cholesterol metabolism in HepG2 cells

We have previously reported that the dipeptide Phe-Pro affects lipid metabolism in vivo and in vitro, but very little is known regarding the mechanism of action of Phe-Pro after it is absorbed by the intestines via PepT1. In this study, we administered a single oral dose of Phe-Pro to rats and quantified its concentration in the portal plasma using LC-TOF/MS analysis. Additionally, the physiological blood concentration of Phe-Pro was added to the lipid accumulation model of HepG2 cells to decrease intracellular cholesterol and increase the expression of CYP7A1 and PPARα mRNA levels. Moreover, we analyzed the binding of PPARα and Phe-Pro using AlphaFold2. We found that Phe-Pro is a ligand for PPARα. To the best of our knowledge, this is the first study that shows Phe-Pro to be present in the portal plasma. We found for the first time that Phe-Pro ameliorated cholesterol metabolism in HepG2 cells.

Retrospective analysis of independent predictors of progression‐free survival in patients with EGFR mutation‐positive advanced non‐small cell lung cancer receiving first‐line osimertinib

Background

Clinically measurable factors affecting the progression‐free survival (PFS) of patients receiving osimertinib as first‐line therapy for epidermal growth factor receptor (EGFR) mutation‐positive advanced non‐small cell lung cancer (NSCLC) have not yet been established.

Methods

We retrospectively reviewed the medical records of 61 patients treated with osimertinib as primary therapy for EGFR mutation‐positive advanced NSCLC at Yokohama City University Medical Center between August 2018 and March 2022. Our objective was to identify the independent predictors of PFS.

Results

The median age of participants was 74 years. Overall, 73.8% had good (0–1) Eastern Cooperative Oncology Group performance status (PS), and 98.4% had histology of adenocarcinoma. The EGFR mutation was exon19 deletion in 52.5% and exon21 L858R in 44.3% of patients. Programmed death‐ligand 1 tumor proportion score >50% was observed in 21.3% and liver metastasis in 9.9% of patients. Median PFS was 19.5 months (95% confidence interval [CI]: 10.6–31.6), and overall survival was not reached. The objective response rate was 68.9%, and disease control rate was 93.4%. Multivariate analysis showed that poor PS (2–4) negatively impacted PFS (hazard ratio, 3.79; 95% CI: 1.46–9.87; p = 0.006). Median PFS in the good PS and poor PS groups was 20.4 months (95% CI: 12.4‐not evaluable) and 7.2 months (95% CI: 7.2–19.5), respectively. Interstitial lung disease of all grades and grade 3 was observed as an adverse event in 6.6 and 4.9% of patients, respectively.

Conclusion

Poor PS was associated with poor prognosis in patients with EGFR mutation‐positive advanced NSCLC treated with osimertinib as first‐line therapy.

Novel Approach for Simultaneous Analysis of Peptide Metabolites from Orally Administered Glycinin in Rat Bloodstream by Coumarin-Tagged MALDI-MS

The lack of an appropriate analytical approach characterizing metabolites from dietary proteins may prevent further studies that could clarify their health benefits. In this study, we attempted to establish a novel analytical assay of peptide metabolites from glycinin using matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS), in combination with the amine derivatization technique with coumarin (Cou). Cou (30 mmol/L) derivatization of peptides under rapid (30 min) and mild (25 °C, pH 8.5) conditions caused higher MS detection of the peptides as compared to nonderivatized peptides. In addition, an MS shift of the target by Cou derivatization (+202.0 m/z) can help to easily discriminate peptide metabolites in glycinin-administered blood, by comparing the MALDI-MS spectra of Cou-derivatized plasma with those of preadministered blood. After the oral administration of glycinin (100 mg/kg) to Sprague-Dawley rats, 15 di- to tetrapeptides were successfully characterized as glycinin-derived metabolites, demonstrating that the proposed Cou-tagged MALDI-MS is an appropriate characterization technique for peptide metabolites.

Plant-derived peptides improving lipid and glucose metabolism

Plant protein-derived peptides, focusing especially on soybean protein-derived peptides have considerable effects on metabolic regulation and modulation such as cholesterol lowering, triglyceride lowering, anti-obesity, inhibition of fatty acid synthase, and antidiabetic effects. The molecules targeted to study the metabolic regulatory functions of the peptides included the following: intestinal cholesterol micelle, cholesterol metabolism-related genes for cholesterol lowering, triglyceride metabolism-related genes for triglyceride lowering and anti-obesity, dipeptidyl peptidase-IV (DPP-IV), α-amylase, α-glucosidase, or glucose metabolism-related genes for lowering blood glucose levels. This review article outlines the physiological functions of plant protein-derived peptides for the improvement of lipid and glucose metabolism in vitro or in vivo.

Anti-Obesity and Hypocholesterolemic Actions of Protamine-Derived Peptide RPR (Arg-Pro-Arg) and Protamine in High-Fat Diet-Induced C57BL/6J Mice

Dietary protamine can ameliorate hyperlipidemia; however, the protamine-derived active peptide and its hypolipidemic mechanism of action are unclear. Here, we report the discovery of a novel anti-obesity and hypocholesterolemic peptide, RPR (Arg-Pro-Arg), derived from protamine in mice fed a high-fat diet for 50 days. Serum cholesterol levels were significantly lower in the protamine and RPR groups than in the control group. White adipose tissue weight was significantly decreased in the protamine and RPR groups. The fecal excretion of cholesterol and bile acid was significantly higher in the protamine and RPR groups than in the control group. We also observed a significant decrease in the expression of hepatic SCD1, SREBP1, and adipocyte FAS mRNA, and significantly increased expression of hepatic PPARα and adipocyte PPARγ1 mRNA in the protamine group. These findings demonstrate that the anti-obesity effects of protamine are linked to the upregulation of adipocyte PPARγ1 and hepatic PPARα and the downregulation of hepatic SCD1 via SREBP1 and adipocyte FAS. RPR derived from protamine has a crucial role in the anti-obesity action of protamine by evaluating the effective dose of adipose tissue weight loss.

Identification of peptides in blood following oral administration of β-conglycinin to Wistar rats

In this study, β-conglycinin (100 mg/kg) was orally administered to Wistar rats in order to identify peptides that may be derived from the protein in the blood. Plasma samples taken from the tail vein up to 8 h after administration were analyzed by matrix-assisted laser desorption/ionization (MALDI) and liquid chromatography-time-of-flight (LC-TOF) mass spectrometry (MS). In total, 126 signals were detected by MALDI-MS. Among the signals, nine oligopeptides (SEL, KGPL, SILGA, DSEL, GDANI, SYFV, CLQSC, GEQPRPF, and LVINEGDA) were successfully identified as β-conglycinin-derived peptides by LC-TOF/MS at a plasma concentration of 0.75-756 pmol/mL. The results demonstrated that β-conglycinin could be the dietary source protein for the oligopeptides produced prior to entering the circulating bloodstream of rats.

The blockade of interleukin-33 released by hepatectomy would be a promising treatment option for cholangiocarcinoma

Interleukin-33 (IL-33), an alarmin released during tissue injury, facilitates the development of cholangiocarcinoma (CCA) in a murine model. However, it is unclear whether IL-33 is associated with human CCA. The aim of this study was to support the following hypothesis: IL-33 is released during hepatectomy for CCA, subsequently facilitating the development of subclinical CCA and eventually leading to recurrent disease. IL-33 expression was assessed in various samples from both humans and mice including resected liver and paired plasma samples collected at hepatectomy and after surgery, and its influences on recurrent disease and patient prognosis were determined. Homogenized human liver samples with high or low IL-33 expression were added to the culture medium of human CCA cells, and the changes in proliferation and migration were evaluated. To examine the effects of inhibiting the IL-33 release induced by hepatectomy, syngraft transplantation of murine CCA cells was performed in C57BL/6J mice with or without IL-33 blockade. The amount of IL-33 released into the plasma during hepatectomy correlated with the background liver expression. High expression of IL-33 in the liver was an independent risk factor for recurrence. Homogenized liver tissue strongly expressing IL-33 increased both the proliferation and migration of tumor cells. Mice who underwent hepatectomy exhibited CCA progression in the remnant liver, whereas blockade of IL-33 during hepatectomy inhibited tumor progression. Thus, we concluded that surgery for CCA with curative intent paradoxically induced IL-33 release, which facilitated CCA recurrence, and anti-IL-33 therapy during hepatectomy might reduce the risk of CCA recurrence.

Single-incision retroperitoneal laparoscopic repair of superior lumbar hernia using self-fixating ProGrip mesh: A case report

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Superior lumbar hernia is an uncommon hernia.

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We performed single-incision retroperitoneal laparoscopic repair.

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Self-fixating mesh without fixation is useful because of no risk of nerve injury.

Introduction

Lumbar hernia is rare and represents less than 1–2% of all abdominal hernias. There are mainly two types of lumbar hernia: superior lumbar hernia and inferior lumbar hernia.

Case presentation

A 65-year-old woman was admitted complaining of a mass in her left lumbar area. Under a diagnosis of superior lumbar hernia, single-incision laparoscopic retroperitoneal repair was performed. A single, 2-cm-long incision was made and the retroperitoneal space was dissected gradually. The hernia orifice was recognized and hernia sac was slipped from the hernia orifice. The collateral branch of subcostal nerve and iliohypogastric nerve were recognized. Laparoscopic self-fixating mesh was placed to cover the hernia orifice without mesh fixation. The patient remained well with no signs of recurrence.

Discussion

In laparoscopic lumbar hernia repair, it is important to be careful not to damage subcostal nerve and iliohypogastric nerve. Self-fixating mesh without fixation is useful due to the prevention from nerve injury. To our best knowledge, this is the first report of single-incision laparoscopic repair for superior lumbar hernia. Single-incision laparoscopic surgery could provide good cosmetic results with minimal incision.

Conclusion

We successfully performed single-incision retroperitoneal laparoscopic repair of superior lumbar hernia using self-fixating mesh.

Epigallocatechin Gallate Induces Upregulation of LDL Receptor via the 67 kDa Laminin Receptor-Independent Pathway in HepG2 Cells

SCOPE

Epigallocatechin gallate (EGCG), an active polyphenol in green tea, exhibits various physiological effects, including activation of low-density lipoprotein receptors (LDLR). The previous studies have suggested that EGCG activates LDLR via extracellular signal-regulated kinase (ERK) pathway in HepG2 cells. However, the detailed molecular mechanism remains unclear. Recently, 67 kDa laminin receptor (67LR) is identified as a receptor for EGCG. Therefore, this study aims to determine whether 67LR is involved in the mechanism of LDLR activation by EGCG.

METHODS AND RESULTS

EGCG induces upregulation of LDLR when 67LR is knocked down in HepG2 cells. Similar effect is observed after the cells are treated with 67LR monoclonal antibody. The loss of antiallergic effect following 67LR siRNA knockdown and 67LR antibody treatment confirms the results since the antiallergic effect of EGCG is known to be mediated by 67LR.

CONCLUSION

EGCG activates LDLR expression via 67LR-independent pathway in HepG2 cells.

[A Case of Disseminated Carcinomatosis of the Bone Marrow Developing 15 Months after Gastrectomy]

The patient was a 60-year-old man who underwent distal gastrectomy for gastric cancer. The pathological diagnosis was Stage ⅡB. He received adjuvant chemotherapy(capecitabine plus oxaliplatin: CapeOX)for 6months and the postoperative course was uneventful. One year and 3 months after surgery, he visited the outpatient department for acute lower back pain. Blood tests showed elevated ALP(3,752 U/L), LDH(308 U/L), and CA19-9(69.4 U/mL)levels. Bone scintigraphy showed multiple bone metastases to the femora, ischium, iliac bone, vertebrae, sternum, costae, and scapulae in a super bone scan. The onset of disseminated intravascular coagulation(DIC)was observed later. The patient was diagnosed with disseminated carcinomatosis of the bone marrow. Radiation therapy was performed and anti-RANKL monoclonal antibody was administered for the bone metastases. Recombinant human soluble thrombomodulin was administered for DIC. He received chemotherapy( TS-1 plus cisplatin: SP)but died 4 months after the diagnosis. The prognosis of disseminated carcinomatosis of the bone marrow is extremely poor. We report this case along with a literature review.

Molecular Mechanism by Which Tea Catechins Decrease the Micellar Solubility of Cholesterol

Tea polyphenols lower the levels of cholesterol in the blood by decreasing the cholesterol micellar solubility. To clarify this mechanism, the interactions between taurocholic acid and (-)-epigallocatechin gallate (EGCg) and its derivatives were investigated. ¹³C NMR studies revealed remarkable chemical-shift changes for the carbonyl carbon atom and the 1″- and 4″-positions in the galloyl moiety. Furthermore, ¹H NMR studies using (-)-EGCg derivatives showed that the number of hydroxyl groups on the B ring did not affect these interactions, whereas the carbonyl carbon atom and the aromatic ring of the galloyl moiety had remarkable effects. The configuration at the 2- and 3-positions of the catechin also influenced these interactions, with the trans-configuration resulting in stronger inhibition activity than the cis-configuration. Additionally, a 1:1 component ratio for the catechin-taurocholic acid complex was determined by electrospray ionization-mass spectrometry. These molecular mechanisms contribute to the development of cholesterol-absorption inhibitors.

Ellagic acid affects mRNA expression levels of genes that regulate cholesterol metabolism in HepG2 cells

Ellagic acid has been shown to improve cholesterol metabolism in animal studies, but the molecular mechanisms underlying this function have not been fully understood. We performed DNA microarray analysis to elucidate the effects of ellagic acid on cholesterol metabolism in HepG2 hepatocytes. This revealed that the expression levels of several genes related to cholesterol metabolism, including the low-density lipoprotein receptor (LDLR), were changed by ellagic acid treatment. Using a real-time PCR and immunoblot we confirmed that ellagic acid treatment up-regulated mRNA and protein expression level of the LDLR. Moreover, In the presence of 25 μM ellagic acid, extracellular apoB protein and MTP mRNA levels were significantly decreased. These findings indicate that ellagic acid improves cholesterol metabolism through the up-regulation of LDLR, down-regulation of MTP mRNA and reduces extracellular apoB levels. The ellagic acid-induced up-regulation of LDLR occurred via the extracellular signal-regulated kinase (ERK) signaling pathway in HepG2 hepatocytes. Abbreviations: LDLR: low-density lipoprotein receptor; apoB: apolipoprotein B; PKC: diacylglycerol-protein kinase C; MAPK: mitogen-activated protein kinase; ERK: p42/44 extracellular signal-regulated kinase; JNK: c-Jun N-terminal kinase; VLDLR: very low density lipoprotein receptor; PPARδ: peroxisome proliferator-activated receptor δ; SREBPs: sterol regulatory element-binding proteins; MTP: microsomal triacylglycerol transfer protein; LPDS: lipoprotein-deficient serum.

Possible involvement of Enterococcus infection in the pathogenesis of chronic pancreatitis and cancer

(Aim) Bacterial infection underlies the pathogenesis of many human diseases, including acute and chronic inflammation. Here, we investigated a possible role for bacterial infection in the progression of chronic pancreatitis. (Materials and Methods) Pancreatic juice was obtained from patients with pancreatic cancer (n = 20) or duodenal cancer/bile duct cancer (n = 16) and subjected to PCR using universal primers for the bacterial 16S ribosomal RNA gene. Bacterial species were identified by PCR using bile samples from four pancreatic cancer patients. PCR products were subcloned into T-vectors, and the sequences were then analyzed. Immunohistochemical and serologic analyses for Enterococcus faecalis infection were performed on a large cohort of healthy volunteers and patients with chronic pancreatitis or pancreatic cancer and on mice with caerulein-induced chronic pancreatitis. The effect of E. faecalis antigens on cytokine secretion by pancreatic cancer cells was also investigated. (Results) We found that 29 of 36 pancreatic juice samples were positive for bacterial DNA. Enterococcus and Enterobacter species were detected primarily in bile, which is thought to be a pathway for bacterial infection of the pancreas. Enterococcus faecalis was also detected in pancreatic tissue from chronic pancreatitis and pancreatic cancer patients; antibodies to E. faecalis capsular polysaccharide were elevated in serum from chronic pancreatitis patients. Enterococcus-specific antibodies and pancreatic tissue-associated E. faecalis were detected in mice with caerulein-induced chronic pancreatitis. Addition of Enterococcus lipoteichoic acid and heat-killed bacteria induced expression of pro-fibrotic cytokines by pancreatic cancer cells in vitro. (Conclusion) Infection with E. faecalis may be involved in chronic pancreatitis progression, ultimately leading to development of pancreatic cancer.

Structure-function properties of hypolipidemic peptides

This review addresses the structure-function properties of hypolipidemic peptides. The cholesterol-lowering peptide (lactostatin: IIAEK) operates via a new regulatory pathway in the calcium-channel-related mitogen-activated protein kinase (MAPK) signaling pathway of cholesterol degradation. The bile acid binding peptide (soystatin, VAWWMY) inhibits the micellar solubility of cholesterol in vitro and cholesterol absorption in vivo. VVYP is the most effective peptide having hypotriglyceridemic action in globin digests. The suppressive effect of globin digest on postprandial hyperlipidemia has been reported in humans. The ability of peptides (KRES, Apolipoprotein A-I mimetic peptides) to interact with lipids, remove LOOH and activate antioxidant enzymes associated with high-density lipoprotein determines their anti-inflammatory and anti-atherogenic properties. The β-conglycinin derived peptides KNPQLR, EITPEKNPQLR, and RKQEEDEDEEQQRE inhibit fatty acid synthase in vitro. These promising findings indicate the need for more conclusive molecular, cellular, and animal and human studies to design innovative new peptides that ameliorate cholesterol and lipid metabolism. PRACTICAL APPLICATIONS: Prevention and amelioration of hypercholesterolemia by dietary regulation are important. Dietary protein and peptides are very useful as regulators of serum cholesterol concentration. Diets low in saturated fat and cholesterol that include soy protein may reduce the risk of heart disease. In Japan, the concept of "food for specified health use" has been introduced for the prevention and treatment of life-style related disease. Thus, peptides derived from food proteins and sources other than food proteins such as peptide-rich functional foods and nutraceutical products, have considerable potential to prevent lifestyle-related diseases, especially hyperlipidemia, as discussed in this review. Furthermore, various strategies have been used for the efficient screening, development, and application of new hypolipidemic peptides. These include the use of phage display (for anti-obesity peptide), peptide mimetics (for anti-atherogenic peptide), and molecular targets such as CYP7A1 (for hypocholesterolemic peptide) and prohibitin (for anti-obesity peptide).

Identification of the active protein in rice bran protein having an inhibitory activity of cholesterol micellar solubility

In our previous study, rice bran protein (RBP) inhibited cholesterol micellar solubility in vitro and decreased serum cholesterol level in rats. In the present study, RBP was separated and purified by size-exclusion chromatography and reversed-phase chromatography. The active protein of RBP related to cholesterol micellar solubility was identified as lectin and non-specific lipid-transfer protein 1 using MALDI-TOF mass spectrometry analysis.

Epigallocatechin gallate induces an up-regulation of LDL receptor accompanied by a reduction of PCSK9 via the annexin A2-independent pathway in HepG2 cells

SCOPE

In animal studies, epigallocatechin gallate (EGCG), the dominant catechin in green tea, has been shown to improve cholesterol metabolism. However, the molecular mechanisms of EGCG underlying these functions have not been fully understood. In this study, we aimed to clarify the molecular mechanisms of the effect of EGCG on cholesterol metabolism mainly in HepG2 cells.

METHODS AND RESULTS

We found that EGCG induced a reduction of the extracellular proprotein convertase subtilisin/kexin 9 (PCSK9) level accompanied by an up-regulation of the LDL receptor (LDLR) in HepG2 cells. The EGCG-induced up-regulation of LDLR occurred via the extracellular signal-regulated kinase (ERK) signaling pathway. Moreover, we showed that EGCG induced a significant early reduction of the extracellular PCSK9 protein level. However, there were no significant changes in the PCSK9 mRNA and the intracellular PCSK9 protein levels induced by EGCG. Annexin A2 knockdown affected the basal LDLR expression and did not affect the EGCG-induced reduction of the extracellular PCSK9 protein level or the up-regulation of LDLR.

CONCLUSION

Annexin A2 possesses an essential function for the basal LDLR expression in HepG2 cells. But, EGCG induces the suppression of PCSK9 accompanied by an up-regulation of LDLR in an annexin A2-independent manner. EGCG attenuates the statin-induced an increase in PCSK9 level.

Calreticulin is highly expressed in pancreatic cancer stem-like cells

Cancer stem‐like cells (CSLCs) in solid tumors are thought to be resistant to conventional chemotherapy or molecular targeting therapy and to contribute to cancer recurrence and metastasis. In this study, we aimed to identify a biomarker of pancreatic CSLCs (P‐CSLCs). A P‐CSLC‐enriched population was generated from pancreatic cancer cell lines using our previously reported method and its protein expression profile was compared with that of parental cells by 2‐D electrophoresis and tandem mass spectrometry. The results indicated that a chaperone protein calreticulin (CRT) was significantly upregulated in P‐CSLCs compared to parental cells. Flow cytometry analysis indicated that CRT was mostly localized to the surface of P‐CSLCs and did not correlate with the levels of CD44v9, another P‐CSLC biomarker. Furthermore, the side population in the CRT^high/CD44v9^low population was much higher than that in the CRT^low/CD44v9^high population. Calreticulin expression was also assessed by immunohistochemistry in pancreatic cancer tissues (n = 80) obtained after radical resection and was found to be associated with patients' clinicopathological features and disease outcomes in the Cox proportional hazard regression model. Multivariate analysis identified CRT as an independent prognostic factor for pancreatic cancer patients, along with age and postoperative therapy. Our results suggest that CRT can serve as a biomarker of P‐CSLCs and a prognostic factor associated with poorer survival of pancreatic cancer patients. This novel biomarker can be considered as a therapeutic target for cancer immunotherapy.

[A Case of Surgical Resection for Gallbladder Cancer with Para-Aortic Lymph Node Metastasis Following Neoadjuvant Chemotherapy with Gemcitabine, Cisplatin, and TS-1]

A 60-year-old woman who visited a doctor during postoperative follow-up for breast cancer was found to have elevated CEA levels. Investigation with FDG-PET CT following enhanced CT suggested gallbladder cancer(GBC)accompanied with para-aortic lymph node(PAL)metastasis. Although we could not obtain any histological evidence, we recommended she be treated as a patient with advanced GBC, and she received 8 courses of chemotherapy consisting of gemcitabine, cisplatin, and TS-1, following the protocol of a clinical trial. After the chemotherapy, imaging exhibited down-staging of the GBC, indicating tumor shrinkage and disappearance of the accumulation of FDG at the tumor sites. We first performed cholecystectomy to obtain histological evidence, and subsequently performed pancreaticoduodenectomy and partial hepatectomy at the gallbladder bed. The pathological diagnosis was pT2N1M0, Stage III B, Evans Grade II b; curative grade A surgery was recommended because the PAL did not contain a tumor any more. The prognosis of advanced GBC with PAL metastasis is extremely poor, but conversion therapy with combined modality therapy including neoadjuvant chemotherapy is a useful strategy to achieve a curative resection.

Interaction between Tea Polyphenols and Bile Acid Inhibits Micellar Cholesterol Solubility

The molecular mechanism by which tea polyphenols decrease the micellar solubility of cholesterol is not completely clear. To clarify this mechanism, this study investigated the interaction between tea polyphenols (catechins and oolongtheanins) and cholesterol micelles. A nuclear magnetic resonance (NMR) study was performed on a micellar solution containing taurocholic acid and epigallocatechin gallate (EGCg), and high-performance liquid chromatography (HPLC) analysis was carried out on the precipitate and the supernatant that formed when EGCg was added to a cholesterol-micelle solution. The data indicated a regiospecific interaction of EGCg with taurocholic acid. Therefore, the ability of EGCg to lower the solubility of phosphatidylcholine (PC) and cholesterol in micellar solutions can be attributed to their elimination from the micelles due to interaction between taurocholic acids and EGCg.

Contributions of ADP and ATP to the increase in skeletal muscle blood flow after manual acupuncture stimulation in rats

OBJECTIVE

To investigate the contributions of adenosine triphosphate (ATP) and adenosine diphosphate (ADP) to the increase in skeletal muscle blood flow (MBF) observed following manual acupuncture (MA) stimulation in rats.

METHODS

Male Sprague-Dawley rats were used as experimental animals (300-370 g, n=40). MA was applied to the right tibialis anterior muscle (TA) for 1 min using a stainless steel acupuncture needle. In eight rats, high-performance liquid chromatography with the microdialysis technique was used to measure local extracellular concentrations of ATP, ADP, adenosine monophosphate (AMP), and adenosine in the TA. In the remaining 32 rats, fluorescent microspheres (15 µm in diameter) were used to measure MBF in the TA following pre-treatment with either the P2 receptor antagonist suramin (100 mg/kg intra-arterially) or saline (control) (n=16 each). Rats receiving MA (Suramin+MA and Saline+MA groups, n=8 each) were compared with untreated rats (Suramin and Saline groups, n=8).

RESULTS

MA significantly increased the local extracellular concentration of ATP, ADP, and adenosine (p<0.05, before MA vs 30 min after MA). In addition, MA significantly increased MBF in rats pre-treated with saline or suramin (p<0.01, Saline vs Saline+MA; p<0.05, Suramin vs Suramin+MA, respectively). However, suramin significantly suppressed this MA-induced increase in MBF (p<0.05, Saline+MA vs Suramin+MA).

CONCLUSIONS

These results suggest that both ATP and ADP partially contribute to the MA-induced increase in MBF via P2 receptors. However, further studies are needed to clarify the contributions of other vasodilators.

Cholesterol-lowering effect of rice bran protein containing bile acid-binding proteins

Dietary plant protein is well known to reduce serum cholesterol levels. Rice bran is a by-product of rice milling and is a good source of protein. The present study examined whether feeding rats a high-cholesterol diet containing 10% rice bran protein (RBP) for 10 d affected cholesterol metabolism. Rats fed dietary RBP had lower serum total cholesterol levels and increased excretion of fecal steroids, such as cholesterol and bile acids, than those fed dietary casein. In vitro assays showed that RBP strongly bound to taurocholate, and inhibited the micellar solubility of cholesterol, compared with casein. Moreover, the bile acid-binding proteins of the RBP were eluted by a chromatographic column conjugated with cholic acid, and one of them was identified as hypothetical protein OsJ_13801 (NCBI accession No. EAZ29742) using MALDI-TOF mass spectrometry analysis. These results suggest that the hypocholesterolemic action of the RBP may be caused by the bile acid-binding proteins.

Identification of a novel hypocholesterolemic protein, major royal jelly protein 1, derived from royal jelly

Royal jelly (RJ) intake lowers serum cholesterol levels in animals and humans, but the active component in RJ that lowers serum cholesterol level and its molecular mechanism are unclear. In this study, we set out to identify the bile acid-binding protein contained in RJ, because dietary bile acid-binding proteins including soybean protein and its peptide are effective in ameliorating hypercholesterolemia. Using a cholic acid-conjugated column, we separated some bile acid-binding proteins from RJ and identified the major RJ protein 1 (MRJP1), MRJP2, and MRJP3 as novel bile acid-binding proteins from RJ, based on matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Purified MRJP1, which is the most abundant protein of the bile acid-binding proteins in RJ, exhibited taurocholate-binding activity in vitro. The micellar solubility of cholesterol was significantly decreased in the presence of MRJP1 compared with casein in vitro. Liver bile acids levels were significantly increased, and cholesterol 7α-hydroxylase (CYP7A1) mRNA and protein tended to increase by MRJP1 feeding compared with the control. CYP7A1 mRNA and protein levels were significantly increased by MRJP1 tryptic hydrolysate treatment compared with that of casein tryptic hydrolysate in hepatocytes. MRJP1 hypocholesterolemic effect has been investigated in rats. The cholesterol-lowering action induced by MRJP1 occurs because MRJP1 interacts with bile acids induces a significant increase in fecal bile acids excretion and a tendency to increase in fecal cholesterol excretion and also enhances the hepatic cholesterol catabolism. We have identified, for the first time, a novel hypocholesterolemic protein, MRJP1, in RJ. Interestingly, MRJP1 exhibits greater hypocholesterolemic activity than the medicine β-sitosterol in rats.

Development of a novel transgenic rice with hypocholesterolemic activity via high-level accumulation of the α' subunit of soybean β-conglycinin

Soybean 7S globulin, known as β-conglycinin, has been shown to regulate human plasma cholesterol and triglyceride levels. Furthermore, the α' subunit of β-conglycinin has specifically been shown to possess low-density lipoprotein (LDL)-cholesterol-lowering activity. Therefore, accumulation of the α' subunit of β-conglycinin in rice seeds could lead to the production of new functional rice that could promote human health. Herein, we used the low-glutelin rice mutant 'Koshihikari' (var. a123) and suppressed its glutelins and prolamins, the major seed storage proteins of rice, by RNA interference. The accumulation levels of the α' subunit in the lines with suppressed glutelin and prolamin levels were >20 mg in 1 g of rice seeds, which is considerably higher than those in previous studies. Oral administration of the transgenic rice containing the α' subunit exhibited a hypocholesterolemic activity in rats; the serum total cholesterol and LDL cholesterol levels were significantly reduced when compared to those of the control rice (var. a123). The cholesterol-lowering action by transgenic rice accumulating the α' subunit induces a significant increase in fecal bile acid excretion and a tendency to increase in fecal cholesterol excretion. This is the first report that transgenic rice exhibits a hypocholesterolemic activity in rats in vivo by using the β-conglycinin α' subunit.

IEC-6 Intestinal Cell Death Induced by Bovine Milk α-Lactalbumin

Potent inhibition of cell proliferation was found for commercial preparations of bovine alpha-lactalbumin on cultured intestinal cell line IEC-6 albeit lot-dependent. The inhibition was irreversible and a single exposure to the culture medium containing alpha-lactalbumin of an active lot for a period as short as 30 min was enough to provoke cell death, possibly through apoptosis. The oligomer fraction from size exclusion chromatography was significantly robust, while the monomer fraction remained totally inert, in inducing cell death. Incubation at 37 degrees C for 5 d with 30% trifluoroethanol in acetate, pH 5.5, in a slowly rotating test tube rendered the monomer fraction cytotoxic. Again, the resulting inhibitory activity was found in the oligomer fraction from size exclusion chromatography, with emergence of subtle peaks at 22- and 30-kDa. Furthermore, the occurrence of SDS-stable 30-kDa as well as 20-kDa bands on electrophoresis was a common feature for alpha-lactalbumin with the activity inducing cell death. Thus, a certain dimeric state can be implicated in the cytotoxicity of bovine alpha-lactalbumin.

Involvement of SDS-Stable HigherMrForms of Bovine Normal Milk α-Lactalbumin in Inducing Intestinal IEC-6 Cell Death

Monomeric 14-kDa bovine alpha-lactalbumin was purified with a preparation of lower molecular weight whey protein concentrate from Holstein cow normal milk followed by size exclusion chromatography. The protein showed a stimulatory rather than an inhibitory effect on the proliferation of a cultured IEC-6 cell line from the rat small intestine. But incubation in 30% trifluoroethanol/acetate buffer (pH 5.5) at 37 degrees C for 5 d in a slowly rotating test tube rendered it highly cytotoxic with concomitant appearance of SDS-stable 20- and 30-kDa forms of alpha-lactalbumin on electrophoresis. Furthermore, alpha-lactalbumin obtained by a one-step purification procedure by affinity chromatography on an anti-alpha-lactalbumin antibody column from the lower molecular weight whey protein concentrate, which had been found to contain several SDS-stable higher M(r) forms of alpha-lactalbumin, exhibited potent inhibitory activity on IEC-6 cell growth. These results indicate the involvement of SDS-stable higher M(r) forms of bovine normal milk alpha-lactalbumin in inducing cell death on the intestinal IEC-6 cell line.

L-Cysteine-induced up-regulation of the low-density lipoprotein receptor is mediated via a transforming growth factor-alpha signalling pathway

Sulphur-containing amino acids regulate plasma cholesterol levels in animals and humans. However, their mechanism of action remains unclear. Low-density lipoprotein receptor (LDLR) plays an important role in cholesterol metabolism. We therefore investigated the effects of sulphur-containing amino acids on the expression of LDLR in hepatocytes. HepG2 cells were cultured in Dulbecco's Modified Eagle's Medium with or without sulphur-containing amino acids and cysteine-containing compounds. We found that L-cysteine increased LDLR mRNA and enhanced LDLR gene promoter activity through the extracellular-signal-related kinase and p38 mitogen-activated protein kinase signalling pathways in HepG2 cells. Moreover, we observed that L-cysteine stimulated the release of transforming growth factor-alpha (TGF-α) and that TGF-α increased the LDLR mRNA levels. This study provides a report of the L-cysteine mediated up-regulation of the LDLR expression via TGF-α signalling pathway. Our findings provide insights into cholesterol homeostasis and amino acid signalling.

Association of a single nucleotide polymorphism in the SH2D1A intronic region with systemic lupus erythematosus

SH2D1A, also known as signaling lymphocytic activation molecule (SLAM)-associated protein (SAP), is an adaptor protein. Recently, it was reported that SAP deficient mice were protected from systemic lupus erythematosus (SLE). In this study, we postulated SH2D1A gene to be a candidate susceptibility gene for SLE and analyzed its association with SLE. A case-control association study was conducted on 5 tag single nucleotide polymorphisms (SNPs) in SH2D1A region in 506 Japanese female SLE patients and 330 healthy female controls. The luciferase assay was performed to determine the functional role of the SNP associated with SLE. One SNP in the intron 2, rs2049995, showed association with SLE (p=0.0110, odds ratio (OR) 1.97, 95% confidence interval (CI) 1.16-3.34, under the dominant model). The association of rs2049995 seemed to be stronger in the subset with the age of onset less than 20 years (p=0.0067, OR 2.65, 95% CI 1.28-5.46). Functional evaluation of rs2049995 showed that reporter gene activity was increased 1.9-fold for the susceptible allele compared with the resistant allele. An intronic SNP of SH2D1A is associated with SLE.