Generation of a recessive dystrophic epidermolysis bullosa mouse model with patient-derived compound heterozygous mutations.

Recessive dystrophic epidermolysis bullosa (RDEB) is an intractable genetic disease of the skin caused by mutations in the COL7A1 gene. The majority of patients with RDEB harbor compound heterozygous mutations-two distinct mutations on each chromosome-without any apparent hotspots in the COL7A1 mutation pattern. This situation has made it challenging to establish a reliable RDEB mouse model with mutations that accurately mimic the genomic background of patients. Here, we established an RDEB mouse model harboring patient-type mutations in a compound heterozygous manner, using the CRISPR-based genome-editing technology i-GONAD. We selected two mutations, c.5818delC and E2857X, that have frequently been identified in cohorts of Japanese patients with RDEB. These mutations were introduced into the mouse genome at locations corresponding to those identified in patients. Mice homozygous for the 5818delC mutation developed severe RDEB-like phenotypes and died immediately after birth, whereas E2857X homozygous mice did not have a shortened lifespan compared to wild-type mice. Adult E2857X homozygous mice showed hair abnormalities, syndactyly, and nail dystrophy; these findings indicate that E2857X is indeed pathogenic in mice. Mice with the c.5818delC/E2857X compound heterozygous mutation presented an intermediate phenotype between the c.5818delC and E2857X homozygous mice. Single-cell RNA sequencing further clarified that the intrafollicular keratinocytes in c.5818delC/E2857X compound heterozygous mice exhibited abnormalities in cell cycle regulation. The proposed strategy to produce compound heterozygous mice, in addition to the established mouse line, will facilitate research on RDEB pathogenesis to develop a cure for this devastating disease.

Comparative analysis of age in monocrotaline-induced pulmonary hypertensive rats.

Pulmonary arterial hypertension (PAH) is a rare, progressive, and fatal cardiovascular/lung disease. The incidence rate is affected by age. Monocrotaline (MCT, 60 mg/kg)-treated rats are widely used as an experimental PAH model. Here, we found that young rats died at a mean of 23.4 days after MCT injection, whereas adult rats survived for over 42 days. However, young (7-week-old) and adult (20-week-old) MCT-treated rats developed PAH, and had upregulated Ca2+-sensing receptor and transient receptor potential canonical subfamily 6 channel expression in pulmonary arteries. The present study provides novel information for elucidating the mechanism underlying the age difference in PAH patients.

In vitro and in vivo characterization of anti-malarial acylphenoxazine derivatives prepared from basic blue 3.

BACKGROUND: Basic blue 3 is a promising anti-malarial lead compound based on the π-delocalized lipophilic cation hypothesis. Its derivatives with nitrogen atoms bonded to carbon atoms at the 3- and 7-positions on the phenoxazine ring were previously shown to exert potent antiprotozoal activity against Plasmodium falciparum, Trypanosoma cruzi, Trypanosoma brucei rhodesiense, and Leishmania donovani parasites in vitro. However, compounds with nitrogen modification at the 10-position on the phenoxazine ring were not evaluated. METHODS: Six acylphenoxazine derivatives (ITT-001 to 006) with nitrogen modification at the 10-position on the phenoxazine ring, which were synthesized from basic blue 3, were characterized and evaluated for anti-malarial activity in vitro with an automated haematology analyzer (XN-30) and light microscopy. Intensity of self-fluorescence was measured using a fluorometer. Localization of basic blue 3 was observed by fluorescence microscopy. Cytotoxicity was evaluated using human cell lines, HEK293T and HepG2 cells. Finally, anti-malarial activity was evaluated in a rodent malaria model. RESULTS: All the six derivatives showed anti-malarial efficacy even against chloroquine-, pyrimethamine-, and artemisinin-resistant field isolates similar to the sensitive strains and isolates in vitro. The efficacy of basic blue 3 was the strongest, followed by that of ITT-001 to 004 and 006, while that of ITT-005 was the weakest. Basic blue 3 showed strong self-fluorescence, whereas ITT derivatives had five- to tenfold lower intensity than that of basic blue 3, which was shown by fluorescence microscopy to be selectively accumulated in the plasmodial cytoplasm. In contrast, ITT-003, 004, and 006 exhibited the lowest cytotoxicity in HEK293T and HepG2 cells in vitro and the highest selectivity between anti-malarial activity and cytotoxicity. The in vivo anti-malarial assay indicated that oral administration of ITT-004 was the most effective against the rodent malaria parasite, Plasmodium berghei NK65 strain. CONCLUSIONS: The six ITT derivatives were effective against chloroquine- and pyrimethamine-resistant strains and artemisinin-resistant field isolates as well as the sensitive ones. Among them, ITT-004, which had high anti-malarial activity and low cytotoxicity in vitro and in vivo, is a promising anti-malarial lead compound.

Gene-Modified Blister Fluid-Derived Mesenchymal Stromal Cells for Treating Recessive Dystrophic Epidermolysis Bullosa.

Recessive dystrophic epidermolysis bullosa (RDEB) is a genodermatosis caused by variants in COL7A1-encoded type VII collagen, a major component of anchoring fibrils. In this study, we developed an ex vivo gene therapy for RDEB using autologous mesenchymal stromal cells (MSCs). On the basis of our previous studies, we first attempted to isolate MSCs from the blister fluid of patients with RDEB and succeeded in obtaining cells with a set of MSC characteristics from all 10 patients. We termed these cells blister fluid-derived MSCs. Blister fluid-derived MSCs were genetically modified and injected into skins of type VII collagen-deficient neonatal mice transplanted onto immunodeficient mice, resulting in continuous and widespread expression of type VII collagen at the dermal-epidermal junction, particularly when administered into blisters. When injected intradermally, the efforts were not successful. The gene-modified blister fluid-derived MSCs could be cultured as cell sheets and applied to the dermis with an efficacy equivalent to that of intrablister administration. In conclusion, we successfully developed a minimally invasive and highly efficient ex vivo gene therapy for RDEB. This study shows the successful application of gene therapy in the RDEB mouse model for both early blistering skin and advanced ulcerative lesions.

Stepwise N-Methylation of Ruthenium and Cobalt 5,15-Diazaporphyrins: Post-Functionalization of Porphyrinoid Catalysts.

Post-functionalization of porphyrinoid catalysts provides a powerful tool for fine-tuning their electronic structure. We have succeeded in the stepwise methylation of the peripheral nitrogen atoms in ruthenium and cobalt 5,15-diazaporphyrins. The axial coordination of an anion to the metal center accelerates the second methylation through charge neutralization. N-Methylation of the diazaporphyrin complexes effectively controls their electron deficiency, Lewis acidity, and catalytic activity.

Characteristics of interstitial lung disease in patients from post-marketing data on metastatic breast cancer patients who received abemaciclib in Japan.

BACKGROUND: This study evaluated characteristics of patients treated with abemaciclib and diagnosed with interstitial lung disease (ILD), using 12-month post-marketing data from the real-world setting in Japan. METHODS: Spontaneous reports of adverse events in patients receiving abemaciclib were collected regularly from healthcare providers (HCPs) from November 30, 2018, to November 29, 2019. Detailed follow-up was requested on suspected ILD cases via questionnaires and/or interviews. Radiological images (when available) were reviewed by an ILD adjudication committee of specialists. The age distribution of patients prescribed abemaciclib in Japan was estimated based on insurance claims data. RESULTS: Of 4700 patients estimated to be exposed to abemaciclib, 82 cases of ILD were reported (46 serious, 13 fatal). Most (91%) had ≥ 1 symptom at diagnosis, commonly dyspnea/shortness of breath (59%), cough (44%), and/or fever (37%). The majority (68%) received steroid therapy (24 [56%] recovered/recovering; 5 [12%] not recovered; 13 [30%] deaths, 1 [2.3%] unknown). No specific imaging patterns or sites of predilection were identified, but a diffuse alveolar damage (DAD) pattern was observed at outcome in 3 of 4 evaluated fatal cases (16 in total evaluated). Features of fatal cases included advanced age, pre-existing interstitial change, and advanced Eastern Cooperative Oncology Group Performance Status. CONCLUSION: Advanced age and a DAD pattern were identified as potential risk factors for cases with poorer outcomes, as previously reported for drug-induced ILD. HCPs should consider the benefit-risk profile when prescribing abemaciclib, informing patients of risks and regularly monitoring treated patients to ensure early detection and treatment of ILD.

Six cases of perforating pilomatricoma: Anetodermic changes with expression of matrix metalloproteinases.

Perforating pilomatricoma (PP) is a rare clinical variant of pilomatricoma presenting as a crusted or ulcerated nodule. Previous reports have suggested that the tumor cells perforate the epidermis through a process of transepithelial elimination. Here, we report six cases of PP and examine the mechanism of transepithelial elimination in PP. Histologically, the dermis above or around the tumor nest exhibited edema, dilated vascular spaces, sparse collagen bundles and absence of elastic fibers, suggesting anetodermic changes in all cases. Immunohistochemistry demonstrated many CD68-positive macrophages around the tumor nests. Matrix metallopeptidase (MMP)-9 and MMP-12 were expressed in the inflammatory cells and tumor cells, and were also present in the epidermis and fibroblasts in all cases. We speculate that in PP anetodermic change caused by MMP and elastases including MMP-9 and MMP-12 may precede elimination of the tumor.