Protective roles of ascorbic acid in oxidative stress induced by depletion of superoxide dismutase in vertebrate cells.

Superoxide dismutases (SODs) are antioxidant proteins that convert superoxide to hydrogen peroxide. In vertebrate cells, SOD1 is mainly present in the cytoplasm, with small levels also found in the nucleus and mitochondrial intermembrane space, and SOD2 is present in the mitochondrial matrix. Previously, the authors conditionally disrupted the SOD1 or SOD2 gene in DT40 cells and found that depletion of SOD1 caused lethality, while depletion of SOD2 led to growth retardation. The observations from previous work showed that the lethality observed in SOD1-depleted cells was completely rescued by ascorbic acid. Ascorbic acid is a water-soluble antioxidant present in biological fluids; however, the exact target for its antioxidant effects is not known. In this study, the authors demonstrated that ascorbic acid offset growth defects observed in SOD2-depleted cells and also lowered mitochondrial superoxide to physiological levels in both SOD1- or SOD2-depleted cells. Moreover, depletion of SOD1 or SOD2 resulted in the accumulation of intracellular oxidative stress, and this increased oxidative stress was reduced by ascorbic acid. Taken together, this study suggests that ascorbic acid can be applied as a nontoxic antioxidant that mimics the functions of cytoplasmic and mitochondrial SODs

Impact of preoperative pathological confirmation on surgical and postoperative outcomes of lung resection for early stage lung cancer

Introduction: The frequency of detection of peripheral pulmonary lesion (PPL) in suspected early lung cancer has been increasing, and whether preoperative pathological diagnosis (PPD) for small PPLs should always be established before their surgical resection can become a worrisome problem for physicians. The aim of the study was to clarify the impact of obtaining PPD on surgical and postoperative outcomes of lung resection for early stage lung cancer.Material and methods: This was a retrospective review of cases that underwent surgical resection for known or suspected primary lung cancer presenting pathological stage 0 or I, enrolled from June 2006 to May 2016. The patients divided into two groups according to PPD group (n = 57) and non-PPD group (n = 157) were compared. The procedure, node dissection, operation time, amount of bleeding, postoperative complications, postoperative length of stay, and postoperative recurrences were analyzed.Results: Among the 214 patients, no significant differences in operation time (248.5 ± 88.6 versus 257.6 ± 89.0, min, mean ± SD, p = 0.328), amount of bleeding (195.3 ± 176.5 vs 188.1 ± 236.1, ml, p = 0.460), postoperative complication (5.2% vs 4.5%, p = 0.728), postoperative length of stay (10.6 ± 6.3 vs 10.4 ± 5.3, days, p = 0.827), or postoperative recurrences (21.0% vs 17.2%, p = 0.550) were seen between PPD and non-PPD groups.Conclusion: Therefore, PPD had less impact on surgical and postoperative outcomes of pathological stage 0 or I lung cancer; direct surgical resection without non-surgical biopsy would be acceptable with careful selection of cases

Reduction of lipid accumulation rescues Bietti’s crystalline dystrophy phenotypes

眼の難病クリスタリン網膜症の発症メカニズムを解明 --治療薬の有力候補発見により創薬研究の進展に期待--. 京都大学プレスリリース. 2018-03-27.Bietti’s crystalline dystrophy (BCD) is an intractable and progressive chorioretinal degenerative disease caused by mutations in the CYP4V2 gene, resulting in blindness in most patients. Although we and others have shown that retinal pigment epithelium (RPE) cells are primarily impaired in patients with BCD, the underlying mechanisms of RPE cell damage are still unclear because we lack access to appropriate disease models and to lesion-affected cells from patients with BCD. Here, we generated human RPE cells from induced pluripotent stem cells (iPSCs) derived from patients with BCD carrying a CYP4V2 mutation and successfully established an in vitro model of BCD, i.e., BCD patient-specific iPSC-RPE cells. In this model, RPE cells showed degenerative changes of vacuolated cytoplasm similar to those in postmortem specimens from patients with BCD. BCD iPSC-RPE cells exhibited lysosomal dysfunction and impairment of autophagy flux, followed by cell death. Lipidomic analyses revealed the accumulation of glucosylceramide and free cholesterol in BCD-affected cells. Notably, we found that reducing free cholesterol by cyclodextrins or δ-tocopherol in RPE cells rescued BCD phenotypes, whereas glucosylceramide reduction did not affect the BCD phenotype. Our data provide evidence that reducing intracellular free cholesterol may have therapeutic efficacy in patients with BCD

Real-Time Imaging of Rabbit Retina with Retinal Degeneration by Using Spectral-Domain Optical Coherence Tomography

Background: Recently, a transgenic rabbit with rhodopsin Pro 347 Leu mutation was generated as a model of retinitis pigmentosa (RP), which is characterized by a gradual loss of vision due to photoreceptor degeneration. The purpose of the current study is to noninvasively visualize and assess time-dependent changes in the retinal structures of a rabbit model of retinal degeneration by using speckle noise-reduced spectral-domain optical coherence tomography (SD-OCT). Methodology/Principal Findings: Wild type (WT) and RP rabbits (aged 4–20 weeks) were investigated using SD-OCT. The total retinal thickness in RP rabbits decreased with age. The thickness of the outer nuclear layer (ONL) and between the external limiting membrane and Bruch’s membrane (ELM–BM) were reduced in RP rabbits around the visual streak, compared to WT rabbits even at 4 weeks of age, and the differences increased with age. However, inner nuclear layer (INL) thickness in RP rabbits did not differ from that of WT during the observation period. The ganglion cell complex (GCC) thickness in RP rabbits increased near the optic nerve head but not around the visual streak in the later stages of the observation period. Hyper-reflective change was widely observed in the inner segments (IS) and outer segments (OS) of the photoreceptors in the OCT images of RP rabbits. Ultrastructural findings in RP retinas included the appearance of small rhodopsin-containing vesicles scattered in the extracellular space around the photoreceptors

Macular ganglion cell layer imaging in preperimetric glaucoma with speckle noise-reduced spectral domain optical coherence tomography.

OBJECTIVE:To visualize the macular ganglion cell layer (GCL) and measure its thickness in normal eyes and eyes with preperimetric glaucoma, using speckle noise-reduced spectral domain optical coherence tomography (SD-OCT). DESIGN:Retrospective consecutive case series. PARTICIPANTS:Thirty-seven eyes of 37 patients with preperimetric glaucoma and 39 normal eyes of 39 volunteers. METHODS:Vertical and horizontal SD-OCT B-scan images were acquired with minimal speckle noise by using eye-tracking to obtain and average 50 B-scans at each identical location of interest. B-scan images were manually analyzed for GCL, retinal nerve fiber layer (RNFL), and inner plexiform layer shapes and thicknesses in the macula. MAIN OUTCOME MEASURES:Macular GCL images and thickness in normal eyes and in eyes with preperimetric glaucoma. RESULTS:The macular GCL was clearly seen on speckle noise-reduced SD-OCT images in normal eyes and eyes with preperimetric glaucoma. In each eye with preperimetric glaucoma, thinning of the macular GCL was visually apparent, particularly on vertical scans. The mean regional macular GCL was most severely thinned in the inferior perifoveal region, where its thickness was <70% of its normal thickness in 30 (81.1%) of the 37 eyes and <50% of its normal thickness in 13 (35.1%) of the 37 eyes. When the sensitivity and specificity for detecting abnormal thinning (outside the lower limit of 99% confidence interval [CI] for the means in the 39 normal eyes) in at least one 0.5-mm segment or sector were compared, the macular GCL on vertical B-scans exhibited higher sensitivity (81.1%) than the other layers on vertical B-scans (99% CI, 5.4%-59.5%; P = 0.00075-0.02100), the macular GCL (99% CI, 40.5%; P = 0.00027) on horizontal B-scans, the other layers (99% CI, 5.4%-48.6%; P<0.00048-0.00400) on horizontal B-scans, and circumpapillary RNFL automatically measured on SD-OCT (54.1%; P = 0.021), and scanning laser polarimetry with variable corneal compensation (24.3%; P = 0.00095). All the macular layers on both the vertical and horizontal B-scans and circumpapillary RNFL thickness exhibited comparable specificity (91.4-100.0%, statistically not different). CONCLUSIONS:Speckle noise-reduced SD-OCT imaging allowed clear visualization and measurement of the macular GCL, which was severely thinned in eyes with preperimetric glaucoma. FINANCIAL DISCLOSURE(S):Proprietary or commercial disclosure may be found after the references

Changes in glycemic control and skeletal muscle mass indices after dapagliflozin treatment in individuals with type 1 diabetes mellitus

Abstract Aims/Introduction Dapagliflozin is used for individuals with type 1 diabetes, although the effect of this medication on skeletal muscle mass is not well established. In addition, there are few studies examining the effects of good glycemic control on skeletal muscle mass in type 1 diabetes patients. We investigated changes in glycemic control and skeletal muscle mass with dapagliflozin in individuals with type 1 diabetes, and the association between these changes. Materials and Methods This was a post‐hoc analysis of a multicenter, open‐label, non‐randomized, prospective, interventional study in individuals with type 1 diabetes. The participants received dapagliflozin at 5 mg/day for 4 weeks, and were reviewed before and after treatment. Weight‐ and height‐corrected appendicular skeletal muscle mass (ASM) were calculated as indices of skeletal muscle mass using bioelectrical impedance analysis. Results A total of 36 individuals were included in the analysis. After the 4 weeks of dapagliflozin treatment, ASM/height2 decreased in the body mass index 60 years. The change in ASM / weight (%) was negatively correlated with the change in glycated hemoglobin (%;P = 0.023). The change in ASM / height2 (kg/m2) was also positively correlated with the change in time within the glucose range of 70–180 mg/dL (P = 0.036). Conclusion Dapagliflozin treatment of individuals with type 1 diabetes, particularly non‐obese individuals and older men, might result in loss of skeletal muscle mass. However, good glycemic control during treatment might prevent the onset and progression of sarcopenia

Novel VCP modulators mitigate major pathologies of rd10, a mouse model of retinitis pigmentosa.

新規神経保護剤により網膜色素変性の進行を抑制することに成功 －難治性眼疾患の進行抑制に期待－. 京都大学プレスリリース. 2014-08-6.Neuroprotection may prevent or forestall the progression of incurable eye diseases, such as retinitis pigmentosa, one of the major causes of adult blindness. Decreased cellular ATP levels may contribute to the pathology of this eye disease and other neurodegenerative diseases. Here we describe small compounds (Kyoto University Substances, KUSs) that were developed to inhibit the ATPase activity of VCP (valosin-containing protein), the most abundant soluble ATPase in the cell. Surprisingly, KUSs did not significantly impair reported cellular functions of VCP but nonetheless suppressed the VCP-dependent decrease of cellular ATP levels. Moreover, KUSs, as well as exogenous ATP or ATP-producing compounds, e.g. methylpyruvate, suppressed endoplasmic reticulum stress, and demonstrably protected various types of cultured cells from death, including several types of retinal neuronal cells. We then examined their in vivo efficacies in rd10, a mouse model of retinitis pigmentosa. KUSs prevented photoreceptor cell death and preserved visual function. These results reveal an unexpected, crucial role of ATP consumption by VCP in determining cell fate in this pathological context, and point to a promising new neuroprotective strategy for currently incurable retinitis pigmentosa

KUS121, an ATP regulator, mitigates chorioretinal pathologies in animal models of age-related macular degeneration

Age-related macular degeneration (AMD) is a leading cause of blindness among elderly people. The appearance of drusen is a clinical manifestation and a harbinger of both exudative and atrophic AMD. Recently, antibody-based medicines have been used to treat the exudative type. However, they do not restore good vision in patients. Moreover, no effective treatment is available for atrophic AMD. We have created small chemicals (Kyoto University Substances; KUSs) that act as ATP regulators inside cells. In the present study, we examined the in vivo efficacy of KUS121 in C-C chemokine receptor type 2-deficient mice, a mouse model of AMD. Systemic administration of KUS121 prevented or reduced drusen-like lesions and endoplasmic reticulum stress, and then substantially mitigated chorioretinal pathologies with significant preservation of visual function. Additionally, we confirmed that long-term oral administration of KUS121 caused no systemic complications in drusen-affected monkeys. ATP regulation by KUSs may represent a novel strategy in the treatment of drusen and prevention of disease progression in AMD

Neuoroprotective efficacies by KUS121, a VCP modulator, on animal models of retinal degeneration

Retinitis pigmentosa (RP) is one of the leading causes of adult blindness and has no established therapy. We have shown that valosin-containing protein (VCP) modulators, Kyoto University Substances (KUSs), ameliorated abnormally low ATP levels by inhibiting the ATPase of VCP, thereby protected several types of cells, including retinal neurons, from cell death-inducing insults. In this study, we found that KUS121, one of the VCP modulators, effectively protects photoreceptors both morphologically and functionally, in two animal models of retinal degeneration, rd12 mice and RP rabbits with a rhodopsin (Pro347Leu) mutation. In rd12 mice, KUS121 suppressed the loss of photoreceptors, not only rods but also cones, as well as the visual function deterioration. Significant protective effects existed even when the medication was started in later stages of the disease. In RP rabbits, KUS121 suppressed thinning of the outer nuclear layer and maintained visual function. In the retinas treated with KUS121, suppression of endoplasmic reticulum stress, activation of mammalian target of rapamycin and suppression of disease-Associated apoptosis were evident. The ability of KUS121 to protect photoreceptors, especially cones, even in later stages of the disease may contribute to the preservation of central vision in RP patients, which is important for quality of vision