BPB Reports

2023 - Vol. 6 No. 2

2023 - Vol. 6

A Demonstration of the Validation Process for Alternative Endotoxin Testing Methods Using PyroSmart NextGen® Recombinant Cascade Reagent Vol.6, No.2, p.68-75
Madeline Kelley , Ingrid Stevens , Toshio Oda , Junko Akiyoshi , Edwin G. Jahngen
Received: April 04, 2023
Accepted: April 14, 2023
Released: April 28, 2023
Abstract Full Text PDF[1M]

The Bacterial Endotoxins Test (BET) uses Limulus amoebocyte lysate (LAL) reagents derived from the blood of horseshoe crabs for detection and quantification of endotoxins from Gram-negative bacteria in parenteral drug products and medical devices. Two types of recombinant reagents using genes cloned from the horseshoe crab genome have become available from several suppliers. One is a recombinant Factor C reagent (rFC), containing only recombinant Factor C, and the second is a recombinant Cascade Reagent (rCR) containing recombinant factor C, recombinant factor B and recombinant proclotting enzyme. Implementation of these recombinant reagents for BET requires validation that demonstrates results equal to or better than those determined by LAL reagents. Previous studies have shown that the PyroSmart NextGen® rCR meets the analytical performance requirements for both the plate and tube reader testing methods and provides equivalent results when testing samples containing autochthonous endotoxin. This study directly compares PyroSmart NextGen® to LAL reagent performance when testing a parenteral drug, which is a critical step for end-user implementation of alternative methods. It is the first published demonstration of an approach to the validation of alternative reagents that includes testing of a specific parenteral drug sample, and the data indicates that PyroSmart NextGen® is more precise when compared to LAL reagents. Relative recovery, linear regression, and Bland-Altman plot analyses also illustrate that PyroSmart NextGen® results are equal to or better than those determined by naturally sourced LAL reagents. This indicates that PyroSmart NextGen® is a useful alternative method for quantifying bacterial endotoxins in parenteral drugs.

Survey on Headache During COVID-19 Infection in People with Chronic Headache Vol.6, No.2, p.62-67
Masakazu Ishii, , Ikumi Ito , Hirotaka Katoh
Received: February 16, 2023
Accepted: March 27, 2023
Released: April 07, 2023
Abstract Full Text PDF[793K]

A questionnaire survey was conducted to clarify the headache situation in people with chronic headache during the new coronavirus disease 2019 (COVID-19) infection. A questionnaire survey was conducted on the internet. The subjects were 600 women in their 20s to 40s who were infected with the 7th wave of COVID-19 infection from July to October 2022. Subjects (55.7%) had headaches at the time of infection, and most of the infected people were recuperating at home. Other headaches (excluding migraine) accounted for about 60% of existing headaches in both the headache group and the headache-free group, but people with migraine accounted for 30.5% of the headache group, and those without headache accounted for 23.3% of the headache-free group. In the headache group, 40.3% had headaches even at the time of vaccination against COVID-19. In both the migraine group and other headache groups, compared to regular headaches, headaches during COVID-19 infection had a greater impact on daily life. Migraine headaches may have worsened in migraine carriers, as accompanying symptoms of migraine were observed at the time of infection. It is therefore important to note that chronic headache patients may develop severe headaches during COVID-19 infection.

PPARγ Protein Expression is Regulated by Cited1 and Cidec in Mouse 3T3-L1 Adipocytes Treated with Troglitazone Vol.6, No.2, p.55-61
Kohei Moriyama , Ayato Kokabu , Atsuko Masumi
Received: December 13, 2022
Accepted: February 07, 2023
Released: April 07, 2023
Abstract Full Text PDF[1M]

We previously reported that treatment with thiazolidinediones (TZDs), such as troglitazone (Tro), downregulates the protein levels of peroxisome proliferator-activated receptor gamma (PPARγ), with enhanced lipid accumulation during 3T3-L1 murine adipocyte differentiation in the presence of 3-isobutyl methylxanthine, dexamethasone, and insulin (MDI). In this study, we performed DNA microarray analysis to compare the gene expression profiles of MDI-induced and MDI/Tro-induced 3T3-L1 adipocytes to elucidate the mechanism underlying the reduction in PPARγ protein expression by Tro treatment. Apoptotic process genes of Gene Ontology were selected from the upregulated genes in MDI/Tro-induced cells and analyzed using real-time RT-PCR and western blotting. For several proteins, higher expression was detected in MDI/Tro-treated 3T3-L1 cells than in MDI-treated cells. Plasmid expression analysis using 293T cells revealed that the expression of cell death-inducing DFFA-like effector C (Cidec) or Cbp/P300-interacting transactivator with Glu/Asp-rich carboxy-terminal domain 1 (Cited1) reduced PPARγ protein expression compared with the vector control. When 3T3-L1 preadipocytes transfected with small interfering RNA targeting Cidec or Cited1 were differentiated in response to MDI or MDI/Tro treatment, the reduction in PPARγ expression in MDI/Tro-treated 3T3-L1 adipocytes was partially suppressed. Our findings indicate that the expression of PPARγ protein is regulated in part by the induction of Cidec and Cited1 in MDI/Tro-treated 3T3-L1 adipocytes.

Regular Article
Intake of Lactobacillus Pentosus TJ515 Prevents the Formation of Retinal Edema in Retinal Vein Occlusion Model Mice Vol.6, No.2, p.47-54
Yae Hidaka , Aika Kuriyama , Anri Nishinaka , Kei Takahashi , Seigo Nakaya , Takeshi Kubota , Shinsuke Nakamura , Masamitsu Shimazawa , Hideaki Hara
Received: January 13, 2023
Accepted: March 19, 2023
Released: April 03, 2023
Abstract Full Text PDF[2M]

Macular edema is a sight-threatening symptom in patients with retinal vein occlusion (RVO) and diabetic retinopathy. It is treated by the intravitreal injection of anti-vascular endothelial growth factor agents, but this has a physical burden on patients. Thus, it is important to develop a treatment that can be administered orally. The probiotic Lactobacillus pentosus TJ515 can reduce inflammation by regulating host immunity via its induction of interleukin-10 (IL-10). However, its action on inflammatory diseases of the retina remains unclear. This study aimed to investigate the preventive effects of L. pentosus TJ515 intake on retinal edema using RVO model mice. Occlusion of the retinal vein led to an increase in the thickness of all retinal layers and the inner nuclear layer. Intake of L. pentosus TJ515 for three weeks suppressed the formation of retinal edema versus vehicle and the control strain (L. pentosus JCM1558). The expression of MCP-1 and MCP-3 was increased in RVO model mice but suppressed by the intake of L. pentosus TJ515. F4/80-positive cells (i.e., activated macrophages) were increased in the retinas of RVO model mice but decreased by the intake of L. pentosus TJ515. Therefore, L. pentosus TJ515 suppressed macrophage migration in the retinas. Treatment of mouse bone marrow-derived macrophages (BMDM) with plasma from mice that had ingested L. pentosus TJ515 decreased the mRNA expression of IL-6 and increased the mRNA expression of IL-10. Thus, oral intake of L. pentosus TJ515 can prevent retinal edema through its anti-inflammatory effects on macrophages and inhibiting effects on macrophage migration.

Promoted Papilloma Formation in a Two-Stage Carcinogenesis Model in Rassf6 Knockout Mice Vol.6, No.2, p.43-46
Mayu Morishita
Received: January 27, 2023
Accepted: March 15, 2023
Released: March 27, 2023
Abstract Full Text PDF[1M]

We have previously reported the generation of Rassf6 knockout mice using CRISPR/Cas technology. Furthermore, we have reported that RASSF6 is implicated in the regulation of the canonical nuclear factor (NF)-κB signaling pathway and that 7,12-dimethylbenz(a)anthracene induced skin inflammation in Rassf6 knockout mice more remarkably than in wild-type mice. In this study, we investigated the role of RASSF6 in skin tumorigenesis using a two-stage carcinogenesis model in Rassf6 knockout mice. Rassf6 knockout mice initially developed significantly more papillomas than did the control wild-type mice. Additionally, macrophages were detected and the canonical NF-κB signal was elevated in papillomas of Rassf6 knockout mice. These results indicated that canonical NF-κB signaling may be involved in papilloma formation. The suppression of NF-κB signaling may have implications for preventing cancer initiation and progression. The findings of this study indicate a tumor suppressive role of RASSF6.

The Structure-Activity Relationship of MPBD and Dictyoquinone Analogs in Dictyostelium discoideum Cell Aggregation Vol.6, No.2, p.37-42
Salma Zulqaida , Tamao Saito , Chihiro Ito , Yoshiaki Takaya
Received: January 05, 2023
Accepted: February 07, 2023
Released: March 07, 2023
Abstract Full Text PDF[1M]

4-Methyl-5-pentylbenzene-1,3-diol (MPBD) (1) and dictyoquinone (DQ or 2-hydroxy-5-methyl-6-pentyl-1,4-benzoquinone) (2) are two polyketides involved in the cell development of Dictyostelium discoideum. We synthesized several MPBD and DQ analogs and tested their ability to recover the cell aggregation delay in the stlA null strain. According to the findings, the alkyl side chain of both compounds facilitates their activity. The parent n-pentyl side chain is required for the cell aggregation.

Cerium (IV) Oxide Nanoparticles Enhance Hepatotoxic and Nephrotoxic Effects of Paraquat, Cisplatin, or Acetaminophen in Mice Vol.6, No.2, p.33-36
Yoshihiro Takahashi , Isao Ishida , Katsuhiro Isoda
Received: February 01, 2023
Accepted: February 23, 2023
Released: March 06, 2023
Abstract Full Text PDF[777K]

Nanomaterials are central to nanotechnology and have many useful properties. Cerium(IV) oxide nanoparticles (nCeO) have catalytic and antioxidant activity, and hold promise in industrial and medical products. However, the potential biological hazards of nCeO have not been addressed. We therefore investigated the in vivo effects and drug interactions of nCeO. Tail vein administration of nCeO did not induce liver and kidney injury in mice but induced liver or kidney damage when co-administered with paraquat, cisplatin or acetaminophen. Therefore, our findings indicate that nCeO are potentially hepatotoxic and nephrotoxic due to drug interactions.