BPB Reports

2021 - Vol. 4 No. 1

2021 - Vol. 4

Regular Article
Methionine is a Key Regulator in the Onset of Atopic Dermatitis in NC/Nga Mice Vol.4, No.1, p.47-54
Takayuki Koga , Fuka Hirayama , Tomomitsu Satoh , Yuji Ishii , Nobuhiro Kashige , Makoto Hiromura , Fumio Soeda , Akihisa Toda
Received: October 30, 2020
Accepted: January 23, 2021
Released: February 10, 2021
Abstract Full Text PDF[1M]

Atopic dermatitis (AD) is a skin disorder that presents with itching and scratching and frequently progresses to a chronic state. AD often develops in patients with an individual or family history of allergic diseases. In addition, AD may develop in patients exposed to environmental stimuli such as air pollutants or dust. However, there can be differences in the magnitude of symptoms between patients even with the same genetic background or exposure to similar environmental conditions. NC/Nga mice have been used as a model for AD. They show AD-like symptoms in an age-dependent manner, even in the absence of AD-inducing agents. In addition, similar to humans, the magnitude of AD symptoms in this model varies between individual mice. However, the mechanisms underlying these differences are unclear. In addition, little is known about the relationship between AD skin symptoms and other organs and tissues. Here, we performed a metabolome analysis on sera from NC/Nga mice to identify factors potentially related to the severity of AD symptoms. The analysis showed a correlation between reduced serum methionine levels and increased severity of AD. In addition, treatment with excess methionine before the onset of AD symptoms suppressed the development of AD. In contrast, administration of methionine after the onset of AD symptoms did not. Importantly, cysteine and taurine, irreversible metabolites of methionine, did not suppress AD development. These results show that methionine, but not its metabolites, is a key factor in the onset, rather than the development of AD.

Browning Effect of Brominated Flame Retardant, TBBP-A, on Undifferentiated Adipocytes Vol.4, No.1, p.41-46
Masahiro Yamasaki , Shinya Hasegawa , Masahiko Imai , Tetsuya Fukui , Noriko Takahashi
Received: December 19, 2020
Accepted: January 27, 2021
Released: February 08, 2021
Abstract Full Text PDF[2M]

Recent studies have suggested that exposure to brominated flame retardants (BFR) may play a pivotal role in the development of high-fat diet-induced obesity and metabolic disorders in the liver. Ketone bodies produced by β-oxidation are utilized by acetoacetyl-CoA synthetase (AACS), a cytosolic ketone body-utilizing enzyme. Previously, we reported that the gene expression of AACS is upregulated in high-fat diet-induced obesity. Here, we examined the effects of BFR, tetrabromobisphenol A (TBBP-A), on gene expression in adipocyte cell line (ST-13). Treatment of differentiated cells with TBBP-A for 48 h did not have any remarkable effects on lipid accumulation and mRNA expression of AACS, PPAR-γ, SCOT, and FAS, whereas in undifferentiated cells, mRNA expression of for the lipid and ketone body utilizing-factors (AACS, perilipin-1, and FAS) and brown adipose tissue (BAT) related factors (UCPs, PRDM16, CIDEA, and LSD-1) was upregulated. These observations suggest that TBBP-A may dysregulate lipid metabolism in undifferentiated adipocytes during ketone body utilization via AACS.

Inhibitory Effect of Anionic Uremic Toxins and Creatinine on the Renal Transport of Methotrexate in Rats Vol.4, No.1, p.36-40
Yuichi Ichimura , Natsumi Kudoh , Shiho Ito , Masako Oda , Hiroshi Saitoh
Received: June 26, 2020
Accepted: January 25, 2021
Released: February 08, 2021
Abstract Full Text PDF[846K]

Various substances called uremic toxins (UTs) accumulate in the blood of patients with chronic kidney disease (CKD) and induce unfavorable effects on the body. It has been reported that some kinds of UTs are excreted extensively in the urine via renal transporters. This characteristic of UTs often becomes a factor for influencing pharmacokinetics of drugs in CKD patients. Even now, however, information on the interactions between UTs and drugs in the process of renal excretion remains limited. Methotrexate (MTX) is widely used for the treatment of rheumatoid and leukemia. It is known that MTX is predominantly excreted in the urine and that this process is mediated by organic anion transporters (OATs). In this study, we investigated the inhibitory effects of two anionic UTs, indoxyl sulfate (IS) and indoleacetic acid (IA), as well as creatinine (Cr) on the renal transport of methotrexate (MTX) using rat renal cortical slices. IS and IA, both substrates for OATs, significantly inhibited the uptake of 50 μM MTX in a concentration-dependent manner at 0.1 mM and 1 mM. In the presence of 1 mM Cr, a cationic guanidino compound, the uptake of MTX was significantly decreased, indicating that Cr is capable of interfering with OATs. In conclusion, it was suggested that the urinary excretion of MTX is extensively suppressed through interactions via OATs when IS, IA, and Cr exist a high concentrations in the blood of CKD patients.

Regular Article
Rab7-Dependent Endocytic Pathways Play an Important Role in Nutrient Absorption during Pre-Weaning Growth Vol.4, No.1, p.27-35
Aya Takimoto
Received: December 04, 2020
Accepted: December 27, 2020
Released: February 08, 2021
Abstract Full Text PDF[17M]

Enterocytes in neonatal rodent endocytose milk materials as macromolecule and digest them into small nutrient molecules. Bulk endocytic membrane flow sustaining nutrient uptake inevitably brings the plasma membrane into large lysosomes, as known as supranuclear vesicles or apical vacuoles which exhibit a unique morphology in infant enterocytes. Endocytic delivery to the large vacuoles required the function of Rab7 GTPase. The Rab7-deficient neonatal enterocytes became filled with abnormal gigantic vacuoles as they migrated from the intervillus pocket to the distal region of the villi and they became defective in taking up macromolecules. Infant animals lacking Rab7 in enterocytes exhibited growth retardation. These results showed that the Rab7-dependent endocytic pathways play an important role in nutrient absorption during pre-weaning growth.

Regular Article
Relationship Between Serum Potassium, Magnesium, and Calcium in Patients Receiving Cetuximab Therapy Vol.4, No.1, p.22-26
Kaito Yamashiro , Atsushi Hirata , Ryosuke Ota , Fumihiko Ogata , Takehiro Nakamura , Naohito Kawasaki
Received: January 09, 2021
Accepted: January 20, 2021
Released: February 04, 2021
Abstract Full Text PDF[1M]

Cetuximab (Cmab) is known to cause electrolyte abnormalities, including hypomagnesemia, hypokalemia, and hypocalcemia. However, little is known about differences in these electrolyte levels between hypomagnesemia and non-hypomagnesemia group in patients receiving Cmab. Therefore, the aim of this study was to clarify the relationship between these serum electrolyte levels in patients undergoing Cmab therapy. A retrospective study was conducted to investigate patients for advanced or recurrent colorectal cancer and head and neck cancer, treated with a regimen composed of Cmab from 2012 to 2020 at the Kindai University Nara Hospital. A total of 113 patients were identified from the medical records, and 24 patients who met the inclusion criteria were enrolled in this study. In the non-hypomagnesemia group, significant positively correlations were observed between calcium and potassium (p = 0.018), between potassium and magnesium (p = 0.008), and between magnesium and calcium (p = 0.038). Simultaneously, in the hypomagnesemia group, no statistically significant correlations were recorded between these electrolytes. The incidences of hypokalemia, hypomagnesemia, and hypocalcemia were 25.0% (6/24), 29.2% (7/24), and 25.0% (6/24), respectively. Additionally, the onset of hypokalemia was significantly associated with the onset of hypocalcemia (p = 0.009). These data suggest that it is important to monitor these electrolyte levels, especially in patients who received Cmab with combination therapy.

Fiber-Knob Region of Adenovirus Type 5 Vector Promotes Migration of A549 Cells Vol.4, No.1, p.17-21
Junpei Kano , Naoya Koizumi , Airi Terada , Ayana Matsuoka , Takamasa Hirai , Tetsuya Nomura , Hiroyuki Mizuguchi , Naoki Utoguchi
Received: November 05, 2020
Accepted: January 11, 2021
Released: February 02, 2021
Abstract Full Text PDF[1M]

Adenoviral vectors based on adenovirus type 5 (Ad5) are commonly used for gene therapy. The Ad5 fiber-knob region primarily interacts with the coxsackievirus and adenovirus receptor (CAR). Reportedly, when stimulated, this receptor participates in the regulation of cell-to-cell adhesion and cell migration. In oncogene therapy, cell migration can have adverse effects by promoting metastasis and infiltration. Alternatively, cell migration may enhance the therapeutic effect of gene therapy by promoting the healing of injured tissues. However, the effect of binding of the Ad fiber-knob region to CAR of target cells has not been investigated in detail. Therefore, the aim of the present study was to investigate the effects of the Ad5 vectors on cell migration with the use of wound healing and migration assays. The results showed that infection with the Ad5 vectors promoted the migration of A549 cells, as determined quantifiably. Furthermore, when the Ad5 fiber-knob protein was applied to A549 cells, the same results were obtained. Together, the results revealed that binding of the Ad fiber-knob protein to CAR causes cell migration as a functional change in target cells. Studying the effect of the Ad fiber-knob protein will lead to the development of a gene transfer vector with greater safety and therapeutic effects.

Regular Article
Comparative Study of Different Epidermal Growth Factor Receptor (EGFR)-Tyrosine Kinase Inhibitors Affecting Lung Cancer Cell Lines Stably Overexpressing EGFR Mutations Vol.4, No.1, p.12-16
Tomohiro Ariyama , Yuichiro Kanno , Sonomi Takizawa , Kiyomitsu Nemoto , Toshihiro Ishii
Received: October 15, 2020
Accepted: January 05, 2021
Released: January 28, 2021
Abstract Full Text PDF[1M]

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are effective drugs against non-small cell lung cancer (NSCLC) cells harboring common EGFR mutations such as in-frame exon 19 deletions (Del19) and the exon 21 L858R point mutations (L858R). However, currently used EGFR-TKIs are less effective against cells showing uncommon EGFR mutations. Because there is less information available on the sensitivities of the uncommon EGFR mutations, it is important to evaluate the effect of EGFR-TKIs on uncommon mutations. In this study, we sought to establish H1299 NSCLC cell lines stably expressing mutated EGFRs having Del18, G719S, or L861Q that are uncommon mutations as well as Del19 or L858R common mutations, and evaluated whether these cell lines could be applied as a prediction system for the therapeutic effects of EGFR-TKIs. In fact, the levels of phosphorylated EGFR in these cell lines were assessed after treatment with various EGFR-TKIs (4 approved and 4 unapproved drugs). Gefitinib, erlotinib, afatinib, and osimertinib, approved drugs, were effective against Del19, L858R, and L861Q mutations. However, these EGFR-TKIs were less effective against G719S and Del18 mutations. The unapproved drugs neratinib and poziotinib were effective against Del19, L858R, Del18, and L861Q mutations. Interestingly, canertinib and sapitinib had effects against Del19, Del18, and L861Q mutations and no effect against L858R mutation. These results indicate that the established cell lines are suitable for assessing the effects of the EGFR-TKIs on EGFR mutations, including uncommon mutations, and that some of the EGFR-TKIs used are also effective against uncommon mutations.

Regular Article
Sorghum (Sorghum bicolor (L.) Moench) Extract Enhances Thiazolidinedione-Induced 3T3-L1 Preadipocyte Differentiation but Inhibits Adipogenic Genes Vol.4, No.1, p.6-11
Makoto Sakurai , Ikumi Aizu , Marina Tonosaki , Yuko Oba , Mei Nagata , Katsuyoshi Kamiie , Atsuko Masumi
Received: November 20, 2020
Accepted: January 17, 2021
Released: January 28, 2021
Abstract Full Text PDF[1M]

Sorghum bicolor (L.) Moench is known as a healthful food. We examined whether a water-soluble sorghum extract (SE) from S. bicolor has an anti-diabetic effect through a mechanism that improves insulin sensitivity or anti-adipogenesis. Although the treatment of SE did not affect the adipogenesis of 3T3-L1 adipocytes induced by isobutyl methylxanthine/dexamethasone/insulin (MDI), it significantly enhanced MDI/thiazolidinedione (TZD)-induced adipogenesis in 3T3-L1 adipocyte differentiation. Real-time polymerase chain reaction analysis showed that treatment with SE reduced the expression of adiponectin, adipocyte protein 2 (aP2), and resistin in 3T3-L1 adipocyte cells. SE suppressed the expression of transcription factors, peroxisome proliferator-activated receptor γ (PPARγ), and CCAAT enhancer-binding protein α in both MDI- and MDI/TZDs-treated 3T3-L1 adipocytes. SE treatment reduced tumor necrosis factor α protein in cell lysates from MDI-induced 3T3-L1 adipocytes but not those induced by MDI/TZD. Our results suggest that SE can serve as an effective food source that improves insulin sensitivity and an anti-obesity agent.

Regular Article
Ropinirole Prevents Light-Induced Retinal Photoreceptor Damage in Mice Vol.4, No.1, p.1-5
Miruto Tanaka , Yuki Inoue , Yuta Yoshino , Yoshiki Kuse , Norifumi Tanida , Koichi Takahashi , Yohei Miyamoto , Hideaki Hara
Received: November 25, 2020
Accepted: January 08, 2021
Released: January 21, 2021
Abstract Full Text PDF[3M]

Photoreceptor cell death leads to blindness in dry age-related macular degeneration (AMD) patients. However, no current therapy exists to treat drug for dry AMD patients. Here, we investigated the neuroprotective effects of ropinirole, a dopamine agonist used to treat Parkinson’s disease, in vitro and in vivo murine dry AMD models. Ropinirole prevented photoreceptor cell death induced by excessive light exposure in vitro. Next, we exposed mice to intensive white fluorescent light, performed morphological analysis of the outer nuclear layer (ONL), and examined electroretinogram (ERG) recordings. Although light exposure reduced ONL thickness and ERG amplitudes, the oral administration of ropinirole improved ONL thickness and a- and b-wave amplitudes, similar to pramipexole treatment. Furthermore, the continuous administration of ropinirole using an osmotic pump attenuated the decrease in retinal thickness induced by chronic light exposure. These findings indicated that ropinirole represents a novel candidate drug for dry AMD treatment.