Mitochondrial Localization of ABC Transporter ABCG2 and Its Function in 5-Aminolevulinic Acid-Mediated Protoporphyrin IX Accumulation

Accumulation of protoporphyrin IX (PpIX) in malignant cells is the basis of 5-aminolevulinic acid (ALA)-mediated photodynamic therapy. We studied the expression of proteins that possibly affect ALA-mediated PpIX accumulation, namely oligopeptide transporter-1 and -2, ferrochelatase and ATP-binding cassette transporter G2 (ABCG2), in several tumor cell lines. Among these proteins, only ABCG2 correlated negatively with ALA-mediated PpIX accumulation. Both a subcellular fractionation study and confocal laser microscopic analysis revealed that ABCG2 was distributed not only in the plasma membrane but also intracellular organelles, including mitochondria. In addition, mitochondrial ABCG2 regulated the content of ALA-mediated PpIX in mitochondria, and Ko143, a specific inhibitor of ABCG2, enhanced mitochondrial PpIX accumulation. To clarify the possible roles of mitochondrial ABCG2, we characterized stably transfected-HEK (ST-HEK) cells overexpressing ABCG2. In these ST-HEK cells, functionally active ABCG2 was detected in mitochondria, and treatment with Ko143 increased ALA-mediated mitochondrial PpIX accumulation. Moreover, the mitochondria isolated from ST-HEK cells exported doxorubicin probably through ABCG2, because the export of doxorubicin was inhibited by Ko143. The susceptibility of ABCG2 distributed in mitochondria to proteinase K, endoglycosidase H and peptide-N-glycosidase F suggested that ABCG2 in mitochondrial fraction is modified by N-glycans and trafficked through the endoplasmic reticulum and Golgi apparatus and finally localizes within the mitochondria. Thus, it was found that ABCG2 distributed in mitochondria is a functional transporter and that the mitochondrial ABCG2 regulates ALA-mediated PpIX level through PpIX export from mitochondria to the cytosol

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Comparison of laser epithelial Keratomileusis with and without mitomycin c for wavefront customized surface ablations

PURPOSE: To investigate the efficacy of mitomycin C (MMC) in preventing haze formation in surface wavefront customized ablations with successful refractive treatment (laser epithelial keratomileusis [LASEK]) and to evaluate the safety of this technique on corneal stroma and enclothelium.METHODS: This study was a prospect masked, randomized clinical trial involving 52 eyes (30 placebo and 22 MMC) of 26 patients. The-manifest refractive spherical equivalent (MRSE), best spectaclecorrected visual acuity, uncorrected visual acuity, corneal pachymetry, topography, aberrometry, endothelial specular microscopy, contrast sensitivity, corneal confocal microscopy, and complaints of pain via a subjective questionnaire were recorded preoperatively and 90 days postoperatively,RESULTS: The mean MRSE at 90 days postoperatively was -0.56 diopters (D) (-4.95 +/- 1.85 D, range: -8.00 to -1.62 D) for the MMC group and -0.49 D (-4.51 +/- 1.81 D, range: -7.75 to -2.25 D) for the placebo group. Higher order aberrations were similar between the placebo and MMC groups 90 days postoperatively (0.538 +/- 0.228 mu m and 0.478 +/- 0.134 mu m, respectively). Analysis of the enclothelial cell count indicated a statistically significant decrease in endothelial cell density (P=.017) after LASEK, independent of MMC use.CONCLUSIONS: The predictability of the final target refraction, induction of high order aberrations, and improvement in contrast sensitivity proved that the use of MMC was equally safe when compared to procedures that did not use MMC. In addition, the procedure was efficient in the prevention of corneal haze.Excimer Laser Santa Cruz, Sao Paulo, BrazilClin Oftalmol Nakano Sta Cruz EYE Inst, Sao Paulo, BrazilUniv Fed Sao Paulo, Sao Paulo, BrazilUniv Fed Sao Paulo, Sao Paulo, BrazilWeb of Scienc

Aortic Aneurysm as a Complication of Granulomatosis with Polyangiitis Successfully Treated with Prednisolone and Cyclophosphamide: A Case Report and Review of the Literature

A 57-year-old Japanese man was admitted to the hospital with back pain and fever, multiple lung nodules, and abdominal aortic aneurysm (AAA). Laboratory tests performed at admission showed an increased proteinase 3 anti-neutrophil cytoplasmic antibody (PR3-ANCA) level. Video-associated thoracoscopic lung biopsy was performed; pathologic examination showed granulation tissue with necrosis and multinucleated giant cells. The diagnosis of granulomatosis with polyangiitis (GPA) was confirmed on the basis of the clinical presentation, laboratory findings, and lung biopsy. All symptoms were ameliorated, and the serum level of PR3-ANCA declined following treatment with prednisolone and cyclophosphamide. Although the association of GPA with AAA is rare, GPA may be included among the large vessel vasculitides that can give rise to aortic aneurysm

Onset of polyarticular juvenile idiopathic arthritis with both anti-cyclic citrullinated peptide antibodies and rheumatoid factor in a 3-year-old girl

Abstract This report describes 3 year old girl with the unusual presentation of polyarticular juvenile idiopathic arthritis (JIA) with anti-cyclic citrullinated peptide (anti-CCP) antibodies and a positive rheumatoid factor (RF). She was initially treated with a nonsteroidal anti-inflammatory drug (NSAID; ibuprofen) followed by methotrexate (MTX, 10 mg/m2/week) and prednisolone (0.25 mg/kg/day), but these treatments were ineffective. Administration of tocilizumab, a humanized antihuman interleukin-6 receptor monoclonal antibody, promptly improved her clinical manifestations, and she has been in complete remission (DAS28 <2.6) without bone erosion and/or destruction. Positivity for both antibodies (anti-CCP and RF) can forecast the severity of JIA (radiographic bone destruction). In such cases the administration of biologic remissive therapy may be prudent early in the disease course.</p