Functional expression of carnitine/organic cation transporter OCTN1 in mouse brain neurons: Possible involvement in neuronal differentiation

The aim of the present study is to clarify the functional expression and physiological role in brain neurons of carnitine/organic cation transporter OCTN1/SLC22A4, which accepts the naturally occurring antioxidant ergothioneine (ERGO) as a substrate in vivo. After intracerebroventricular administration, the distribution of [ 3H]ERGO in several brain regions of octn1 -/- mice was much lower than that in wild-type mice, whereas extracellular marker [ 14C]mannitol exhibited similar distribution in the two strains. The [ 3H]ERGO distribution in wild-type mice was well correlated with the amount of ERGO derived from food intake and the OCTN1 mRNA level in each brain region. Immunohistochemical analysis revealed colocalization of OCTN1 with neuronal cell markers microtubule-associated protein 2 (MAP2) and βIII-tubulin in mouse brain and primary cultured cortical neurons, respectively. Moreover, cultured cortical neurons exhibited time-dependent and saturable uptake of [ 3H]ERGO. These results demonstrate that OCTN1 is functionally expressed in brain neurons. The addition of ERGO simultaneously with serum to culture medium of cortical neurons attenuated mRNA and protein expressions of MAP2, βIII-tubulin and synapse formation marker synapsin I, and induced those of sex determining region Y-box 2 (Sox2), which is required to maintain the properties of undifferentiated neural stem cells. In neuronal model Neuro2a cells, knockdown of OCTN1 by siRNA reduced the uptake of [ 3H]ERGO with concomitant up-regulation of oxidative stress marker HO-1 and Sox2, and down-regulation of neurite outgrowth marker GAP43. Interestingly, the siRNA knockdown decreased the number of differentiated Neuro2a cells showing long neurites, but increased the total number of cells. Thus, OCTN1 is involved in cellular differentiation, but inhibits their proliferation, possibly via the regulation of cellular oxidative stress. This is the first evidence that OCTN1 plays a role in neuronal differentiation and proliferation, which are required for brain development. Crown Copyright © 2012

Localization of Xenobiotic Transporter OCTN1/SLC22A4 in Hepatic Stellate Cells and Its Protective Role in Liver Fibrosis

Xenobiotic transporters play key roles in disposition of certain therapeutic agents, although limited information is available on their roles other than pharmacokinetic issues. Here, suppressive effect of multispecific organic cation transporter OCTN1/SLC22A4 on liver fibrosis was proposed in liver injury models. After injection of hepatotoxins such as dimethylnitrosamine (DMN) or concanavalin A, hepatic fibrosis, and oxidative stress, evaluated in terms of Sirius red and 4-hydroxy-2-nonenal staining, respectively, were more severe in liver of octn1/slc22a4 gene knockout (octn1-/-) mice than that in wild-type mice. DMN treatment markedly increased α-smooth muscle actin and F4/80, markers of activated stellate and Kupffer cells, respectively, in liver of octn1-/-, but had less effect in wild-type mice. Thus, octn1/slc22a4 gene deletion results in more severe hepatic fibrosis, oxidative stress, and inflammation. DMN-treated wild-type mice showed increased Octn1 staining and hepatic concentration of its food-derived antioxidant ergothioneine (ERGO). The upregulated Octn1 was co-localized with α-smooth muscle actin. Functional expression of Octn1 was demonstrated in activated human hepatic stellate cell lines, LI90 and LX-2. Provision of ERGO-rich feed ameliorated DMN-induced liver fibrosis and oxidative stress. Overall, Octn1 is upregulated in activated stellate cells, resulting in increased delivery of its substrate antioxidant ERGO and a protective effect against liver fibrosis. © 2016 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.Embargo Period 12 month

The Long-Term Changes in Midday Photoinhibition in Rice (Oryza sativa L.) Growing under Fluctuating Soil Water Conditions

Rice crops growing under fluctuating soil water conditions in a rainfed field frequently experience severe photoinhibition at midday, potentially decreasing their biomass production. In this study, the long-term changes in midday photoinhibition in five rice cultivars growing under variable soil water conditions in a rainfed field were evaluated by determining the maximum quantum yield of photosystem II (Fv/Fm). Fv/Fm was generally lower under rainfed conditions than under flooded conditions at 65 – 75 days after sowing (DAS), but was similar under both conditions at 109 – 124 DAS. This mitigation of photoinhibition over time is likely an up-regulation of mechanisms to dissipate excess electrons, and an analysis of covariance showed that the degree of mitigation under the rainfed condition varied among the cultivars. Such genotypic differences in the long-term changes in Fv/Fm might be determined by the capacity of the cultivar to adapt to drought conditions

Preoperative Ahlbäck radiographic classification grade significantly influences clinical outcomes of double level osteotomy for osteoarthritic knees with severe varus deformity

Abstract Purpose The purpose of this study was to examine the relationship between preoperative Ahlbäck radiographic classification grade and the clinical outcomes of double level osteotomy (DLO) performed for osteoarthritic knees with severe varus deformity. Methods The study population comprised a consecutive series of 99 knees (68 patients) for which DLO was performed and follow‐up results for a minimum of two years were available. The Ahlbäck radiographic classification system was used to determine the osteoarthritic grade. The following radiological parameters for alignment and bone geometry were measured: mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), joint‐line convergence angle (JLCA), and mechanical tibiofemoral angle (mTFA). Clinical results were assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the International Knee Documentation Committee (IKDC) subjective score preoperatively and at 2 years after surgery. Difference between preoperative and postoperative measurements as well as relationship between Ahlbäck grade and radiological/clinical results were statistically assessed. Results The average age of the study participants was 60.9 ± 6.2 years and the mean follow‐up period was 45.4 ± 15.2 months. Each of the radiological parameters exhibited preoperative abnormal values. Knees with Ahlbäck grade 3 and 4 osteoarthritis exhibited significantly greater JLCA and mTFA than grade 1 knees. Two years post‐surgery, all radiological parameter values measured within a normal range. Clinical evaluation showed significant improvement in KOOS after surgery. Analysis of the relationship between Ahlbäck grade and clinical score showed that the 2‐year postoperative KOOS scores in grade 3 and 4 osteoarthritic knees were significantly lower than grade 1 knees (with the mean 2‐year KOOS scores of 350.0 ± 79.9, 317.9 ± 78.3, and 420.2 ± 42.9, respectively). Conclusions While DLO may produce significant radiological and clinical improvement in knees with joint space obliteration, Ahlbäck grade 3 and 4 osteoarthritic knees associated with larger JLCA and mTFA showed less satisfactory clinical results compared to grade 1 knees. Level of Evidence: IV case series

Biodistribution and radiation dosimetry of the novel hypoxia PET probe [F-18]DiFA and comparison with [F-18]FMISO

BackgroundTo facilitate hypoxia imaging in a clinical setting, we developed 1-(2,2-dihydroxymethyl-3-[F-18]-fluoropropyl)-2-nitroimidazole ([F-18]DiFA) as a new tracer that targets tumor hypoxia with its lower lipophilicity and efficient radiosynthesis. Here, we evaluated the radiation dosage, biodistribution, human safety, tolerability, and early elimination after the injection of [F-18]DiFA in healthy subjects, and we performed a preliminary clinical study of patients with malignant tumors in a comparison with [F-18]fluoromisonidazole ([F-18]FMISO).ResultsThe single administration of [F-18]DiFA in 8 healthy male adults caused neither adverse events nor abnormal clinical findings. Dynamic and sequential whole-body scans showed that [F-18]DiFA was rapidly cleared from all of the organs via the hepatobiliary and urinary systems. The whole-body mean effective dose of [F-18]DiFA estimated by using the medical internal radiation dose (MIRD) schema with organ level internal dose assessment/exponential modeling (OLINDA/EXM) computer software 1.1 was 14.40.7 mu Sv/MBq. Among the organs, the urinary bladder received the largest absorbed dose (94.7 +/- 13.6 mu Sv/MBq). The mean absorbed doses of the other organs were equal to or less than those from other hypoxia tracers. The excretion of radioactivity via the urinary system was very rapid, reaching 86.4 +/- 7.1% of the administered dose. For the preliminary clinical study, seven patients were subjected to [F-18]FMISO and [F-18]DiFA positron emission tomography (PET) at 48-h intervals to compare the two tracers' diagnostic ability for tumor hypoxia. The results of the tumor hypoxia evaluation by [F-18]DiFA PET at 1h and 2h were not significantly different from those obtained with [F-18]FMISO PET at 4h ([F-18]DiFA at 1h, p=0.32; [F-18]DiFA at 2h, p=0.08). Moreover, [F-18]DiFA PET at both 1h (k=0.68) and 2h (k=1.00) showed better inter-observer reproducibility than [F-18]FMISO PET at 4h (k=0.59).Conclusion [F-18]DiFA is well tolerated, and its radiation dose is comparable to those of other hypoxia tracers. [F-18]DiFA is very rapidly cleared via the urinary system. [F-18]DiFA PET generated comparable images to [F-18]FMISO PET in hypoxia imaging with shorter waiting time, demonstrating the promising potential of [F-18]DiFA PET for hypoxia imaging and for a multicenter trial