冈山理科大学

Antibody-based therapeutics are promising for treating central nervous system (CNS) diseases; however, brain delivery is severely restricted by the blood-brain barrier (BBB). Intranasal administration has gained attention as a noninvasive route proposed to reduce the impact of the BBB; however, the efficiency of delivering large biomolecules, such as antibodies, remains insufficiently characterized. This study aimed to investigate whether cell-penetrating peptides (CPPs) could increase detectable IgG levels in the cerebrospinal fluid (CSF) following intranasal administration in mice. Rabbit IgG was intranasally administered to ICR mice, either alone or in combination with CPPs (R9, Penetratin, or L17E). IgG levels in the CSF and serum were quantified by ELISA, and both time-course and dose-dependent effects were analyzed. IgG alone was not detected in the CSF, whereas serum IgG levels increased dose-dependently. Co-administration of Penetratin or L17E resulted in detectable CSF IgG levels, with L17E exceeding Penetratin. By contrast, no delivery was observed in the R9 group. Serum IgG levels also increased in the Penetratin and L17E groups. Time-course analysis with L17E showed that CSF IgG reached its highest measured level at 24 h and declined thereafter, whereas serum IgG reached higher levels at earlier time points and remained relatively stable. Dose-response analysis revealed linear increases in serum IgG, while CSF IgG levels depended on the concentration of L17E. These findings indicate that co-administration with amphipathic CPPs, particularly L17E, enables detectable IgG delivery to the CSF following intranasal administration in mice, although the underlying mechanisms and therapeutic relevance remain to be clarified.

Blood purification using immunoadsorbent columns is a therapeutic strategy for removing pathogenic autoantibodies in autoimmune diseases. Currently available columns have limitations: Trp/Phe columns offer cost-effectiveness and sterilizability, but lack antigen specificity and have limited capacity to remove diverse pathogenic autoantibodies; whereas Protein A/peptide/anti-human IgG columns target all antibodies, regardless of pathogenicity, limiting specificity, and often require sterile production due to low stability under sterilization conditions, except for peptide ligands. Full-length autoantigen-immobilized immunoadsorbent columns have great potential to specifically adsorb targeted autoantibodies, because autoantibodies recognize diverse epitopes that vary among individuals. However, it is challenging to prepare biologically active autoantigens on a large scale and maintain the quality of antigen-immobilized columns after sterilization. This study introduced a novel approach for preparing sterilizable antigen-immobilized columns that target autoantibodies, excluding those with conformational epitope specificity. Two type I transmembrane protein-coding extracellular domains associated with autoimmunity and their rabbit antisera were used as models. Recombinant human contactin-associated protein-like 2 (Caspr2) and muscle-specific tyrosine-protein kinase receptor (MuSK) were expressed as bacterial inclusion bodies. These compounds were solubilized and purified using Cys-specific chemical cationization. Columns immobilized with water-soluble S-cationized Caspr2 or MuSK effectively captured specific antibodies from rabbit antisera against each antigen, retaining their capacity after standard sterilization. This approach offers a promising solution for developing immunoadsorbent columns with enhanced specificity and sterilizability and is applicable to various autoantibody-related disorders.

Diffusion tensor imaging (DTI) has been used in veterinary medicine for cerebral infarctions and degenerative diseases in recent years. Defining normal values for the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) to detect lesions is challenging because these values depend on anatomical differences in the spinal cord, magnetic resonance imaging (MRI) machine model, magnetic field strength, and measurement protocol. Shannon entropy is the average amount of information and is a measure of the variability or complexity, of distributed numbers. The purpose of this study is to evaluate whether Shannon entropy can serve as a useful new indicator for interpreting the structural integrity of the canine spinal cord. We used six beagle dogs with no spinal cord disease, as confirmed by neurological examination and magnetic resonance imaging. We calculated the respective values for the cervical and thoracolumbar spinal cord under the 3 T magnetic field. The ADC and FA values (mean ± standard error) of the cervical spinal cord were 1.11 ± 0.05 × 10-3 mm2/s and 0.64 ± 0.02. The thoracolumbar spinal cord had values of 1.16 ± 0.04 × 10-3 mm2/s and 0.58 ± 0.02. The ADC and FA values of the spinal cord reflected anatomical differences, and no fixed normal values were observed for the entire spinal cord. Shannon entropy was 5.67 ± 0.45. No significant differences were observed in the values at any intervertebral level. These results suggest that Shannon entropy is more useful than the ADC and FA values. Shannon entropy may be able to differentiate between normal tissue and lesions, independent of various MRI conditions.

Effective pollinators of Arisaema nambae Kitam., endemic to western Okayama and eastern Hiroshima prefectures, western Japan, were determined, and 113 insects from 24 spathes of A. nambae in three populations in Okayama Prefecture were collected. Most floral visitors were fungus gnats (Mycetophilidae and Sciaridae). Their maximum body width was less than the internal diameter (ca. 2 mm) of the exit at the bottom of the staminate spathe. Pollen grains of Arisaema attached to the bodies of fungus gnats collected from pistillate spathes provided evidence that they visited the pistillate spathe after escaping from staminate spathes. Based on their visitation frequency, size compatibility between their body and the exit from the staminate spathes and the pollen loads they carry, fungus gnats appear to play an important role in the pollination of A. nambae. (c) 2023 National Science Museum of Korea (NSMK) and Korea National Arboretum (KNA), Publishing Services by Elsevier. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).