Molecular Design of Cyclic Peptides with Cell Membrane Permeability and Development of MDMX-p53 Inhibitor.

Cyclic peptides have been expected to be one of the modalities of intracellular protein-protein interaction (PPI) inhibitors, but they are generally known to have low cell membrane permeability. In this study, we focused on the conformation of cyclic peptides in the cell membrane to determine the requirement for their cell membrane permeability through passive diffusion. Utilizing the requirement, we searched for structures with high affinity for MDMX via computational chemistry and acquired cyclic peptide 19 (Papp = 0.80 × 10-6 cm s-1, IC50 = 0.07 µM).

Allyl isothiocyanate, an activator of TRPA1, increases gastric mucosal blood flow through calcitonin gene-related peptide and adrenomedullin in anesthetized rats.

Allyl isothiocyanate (AITC) activates transient receptor potential ankyrin 1 (TRPA1) channel, which is involved in the control of intestinal mucosal blood flow. However, the mechanism underlying the increased gastric mucosal blood flow (GMBF) in response to AITC remains unknown. We examined the effect of AITC on GMBF in the ex vivo stomachs of normal and sensory deafferented rats using a laser Doppler flowmeter. Mucosal application of AITC increased GMBF in a concentration-dependent manner. Repeated AITC exposure resulted in a marked desensitization. The increased GMBF response induced by AITC was entirely blocked by co-application of TRPA1 channel blockers HC-030031 or AP-18. Increased GMBF in response to AITC was significantly attenuated by chemical deafferentation following systemic capsaicin injections (total dose: 100 mg/kg). In contrast, increased GMBF responses to capsaicin, a transient receptor potential vanilloid 1 (TRPV1) activator, were completely abolished by chemical deafferentation. The increased GMBF response to AITC was markedly inhibited by BIBN 4096, a calcitonin gene-related peptide receptor (CGRP) antagonist, or AGP-8412, an adrenomedullin receptor antagonist. These results suggest that AITC-stimulated TRPA1 activation results in the increased GMBF through the release of CGRP and adrenomedullin.

Case Report: Acupuncture is an effective treatment for olfactory dysfunction in the post COVID-19 condition.

Olfactory dysfunction in the post COVID-19 condition reported worldwide are refractory for some patients. For this reason, appropriate treatment is desired. In this article, we describe two cases of olfactory dysfunction in the post COVID-19 condition that was improved by traditional acupuncture treatment. By using the Yingxiang point (LI20), which is said to improve the sense of smell since ancient times, acupuncture treatment was performed 1-2 times a week in two patients about 6 and 7 months after the diagnosis of COVID-19. Acupuncture needles with a body length of 30 mm and a body diameter of 0.16 mm were inserted about 10 mm deep into the skin. We stimulated LI20 of the right and left sides until the patients felt the de qi sensation (acupuncture resonance), and left needles in the points for about 15 min. Immediately after the acupuncture treatment, the symptoms of olfactory dysfunction were alleviated, and the improvement in olfactory dysfunction lasted for 2-4 days. As the number of acupuncture treatments increased, the time until the flareup of olfactory dysfunction was prolonged, and the symptoms tended to decrease. In our experience, the acupuncture treatment was effective in a short period for treating residual olfactory dysfunction of the post COVID-19 condition, suggesting that acupuncture may serve as an adjunct to modern medical treatment, and it may also be a new option for patients who are resistant to Western medical treatment or unable to continue treatment because of side effects. In conclusion, acupuncture may be a new option for patients who are resistant to modern medical treatment or who are unable to continue treatment because of side effects.

Photo-Degradable Protein-Polymer Hybrid Shells for Caging Living Cells.

There is growing demand for the precise remote control of cellular functions in various fields. Herein, a method for caging mammalian cells by coating with photodegradable protein-polymer hybrid shells to photo-control their functions without genetic engineering is reported. A layer-by-layer assembly of photocleavable synthetic materials through biotin-streptavidin (SA) binding was employed for cell coating. The cell surfaces were first biotinylated with photocleavable biotinylated poly(ethylene glycol)(PEG)-lipid and then coated by repeatedly layering SA and micelles of the PEG-lipid and photocleavable biotinylated four-arm PEG. The cell extension and adhesion were suppressed with the shells and then triggered with the degradation of the shells by light exposure. Macrophage phagocytosis was also stopped by caging with the shells and restarted by light-guided uncaging. This study provides the first proof of principle that cellular functions can be remotely controlled by steric hinderance of cell surfaces with photodegradable materials.

Photodegradable avidin-biotinylated polymer conjugate hydrogels for cell manipulation.

Protein-synthetic polymer hybrid hydrogels crosslinked via protein-ligand binding are promising materials for the three-dimensional culture of various cells, while photo-responsive hydrogels have been widely used for the spatio-temporal control of cell functions and patterning. Photo-responsive protein-polymer hybrid hydrogels are therefore attractive candidates for use in cell and artificial tissue fabrication; however, no examples combining these properties have been reported to date. Herein, a photodegradable hydrogel consisting of avidin and biotinylated polyethylene glycol (PEG) was developed as a multi-functional matrix for cell culture and sorting. A four-branched PEG with a biotinylated photocleavable group at the end of each chain was crosslinked with avidin to produce a photodegradable hydrogel. A cytokine-dependent immunocyte was successfully cultured in the hydrogel by supplying cytokine from a medium layered on the hydrogel. Additionally, the adhesion and survival of fibroblasts could be controlled by decorating the hydrogel with a biotinylated cell-adhesive peptide. Cells embedded in the hydrogels could be recovered without cell damage as a result of light-induced hydrogel degradation. Moreover, model target cells expressing red fluorescent protein were selectively liberated from a hydrogel containing cells of different colors by irradiating with a targeted light. Owing to both the selective biotin-binding ability of avidin and the photocleavable properties of the synthetic polymer, the hydrogels were easy to prepare and decorate with functional molecules; they provided an internal structure suitable for cell culture, and allowed light-guided cell manipulation. The hydrogels are therefore expected to contribute to various cell fabrication processes as useful cell engineering and sorting tools.

Relationship between n-3 Polyunsaturated Fatty Acids and Extent of Vessel Disease in Patients with ST Elevation Myocardial Infarction.

A relationship between serum polyunsaturated fatty acids (PUFAs) and cardiovascular disease has been reported; however, the existence of a relationship between serum PUFAs and extent of vessel disease (VD) in patients with ST elevation myocardial infarction (STEMI) remains unclear.Between July 2011 and June 2015, 866 consecutive STEMI patients underwent emergent percutaneous coronary intervention, 507 of whom were enrolled and classified into three groups according to the initial angiograms: 1VD, 294 patients; 2VD, 110 patients; and 3VD/left main trunk disease (LMTD), 103 patients. Serum levels of PUFAs, including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid, and other laboratory data during hospitalization were evaluated.The serum EPA level in the 3VD/LMTD group was significantly lower than that in the 1VD group (55.5 ± 22.1 versus 66.2 ± 28.7, P = 0.002) and was slightly lower than that in the 2VD group (55.5 ± 22.1 versus 65.2 ± 28.9, P = 0.0167). Multivariate adjustment analysis revealed that age ≥ 70 years (odds ratio, 1.72; 95% confidence interval, 1.03-2.89; P = 0.038) and a low serum EPA level (odds ratio, 0.98; 95% confidence interval, 0.99-1.00; P = 0.023) were independent risk factors for 3VD/LMTD, while a low serum DHA level was not.A low serum EPA level may be more strongly related than a low serum DHA level to the extent of VD in STEMI patients. Age ≥ 70 years and a low serum EPA level may be independent risk factors for 3VD/LMTD.

Sterically bulky caging for light-inducible protein activation.

A method for caging a target protein with steric regulator molecules was developed to enable simple, strict, light-induced control of protein activity.

Optical coherence tomography findings in lesions after sirolimus-eluting stent implantation with peri-stent contrast staining.

BACKGROUND: We have sometimes noted abnormal angiographic coronary dilatation, <50% of the reference vessel, at the site of sirolimus-eluting stent implantation, suggesting contrast staining outside the stent struts and named this finding peri-stent contrast staining (PSS). Little was known about optical coherence tomography findings of lesions with PSS. METHODS AND RESULTS: Between May 2008 and March 2010, we performed optical coherence tomography for 90 in-stent restenosis lesions after sirolimus-eluting stent implantation. We found PSS in 20 of the 90 lesions by coronary angiography. The differences in optical coherence tomography findings, including incomplete stent apposition, multiple interstrut hollows (MIH), strut coverage, and thrombus, were compared between lesions with PSS and those without PSS. PSS is defined as contrast staining outside the stent contour extending to >20% of the stent diameter measured by quantitative coronary angiography. MIH is defined as multiple hollows (the maximum depth >0.5 mm) existing between and outside well-apposed stent struts. Both incomplete stent apposition (60.0% versus 10%; P<0.001) and MIH (85.0% versus 25.7%; P<0.001) were frequently observed in lesions with PSS than in lesions without PSS. Among the 20 lesions with PSS, there was only 1 lesion in which we found neither MIH nor incomplete stent apposition, but only minor dissection. Uncovered struts (11.6% versus 3.9%; P=0.001), malapposed struts (2.0% versus 0.0%; P<0.001), and red thrombus (35% versus 10%; P=0.012) were frequently observed in lesions with PSS than in lesions without PSS. CONCLUSIONS: PSS might be closely associated with 2 different optical coherence tomography findings, MIH and incomplete stent apposition, in lesions after sirolimus-eluting stent implantation.

Fission yeast Arp6 is required for telomere silencing, but functions independently of Swi6.

The actin-related proteins (Arps), which are subdivided into at least eight subfamilies, are conserved from yeast to humans. A member of the Arp6 subfamily in Drosophila, Arp4/Arp6, co-localizes with heterochromatin protein 1 (HP1) in pericentric heterochromatin. Fission yeast Schizosaccharomyces pombe possesses both an HP1 homolog and an Arp6 homolog. However, the function of S.pombe Arp6 has not been characterized yet. We found that deletion of arp6(+) impaired telomere silencing, but did not affect centromere silencing. Chromatin immunoprecipitation assays revealed that Arp6 bound to the telomere region. However, unlike Drosophila Arp4/Arp6, S.pombe Arp6 was distributed throughout nuclei. The binding of Arp6 to telomere DNA was not affected by deletion of swi6(+). Moreover, the binding of Swi6 to telomere ends was not affected by deletion of arp6(+). These results suggest that Arp6 and Swi6 function independently at telomere ends. We propose that the Arp6-mediated repression mechanism works side by side with Swi6-based telomere silencing in S.pombe.