Behavioral and histological analyses of the mouse Bassoon p.P3882A mutation corresponding to the human BSN p.P3866A mutation.

Tauopathy is known to be a major pathognomonic finding in important neurodegenerative diseases such as progressive supranuclear palsy (PSP) and corticobasal degeneration. However, the mechanism by which tauopathy is triggered remains to be elucidated. We previously identified the point mutation c.11596C > G, p.Pro3866Ala in the Bassoon gene (BSN) in a Japanese family with PSP-like syndrome. We showed that mutated BSN may have been involved in its own insolubilization and tau accumulation. Furthermore, BSN mutations have also been related to various neurological diseases. In order to further investigate the pathophysiology of BSN mutation in detail, it is essential to study it in mouse models. We generated a mouse model with the mouse Bassoon p.P3882A mutation, which corresponds to the human BSN p.P3866A mutation, knock-in (KI) and we performed systematic behavioral and histological analyses. Behavioral analyses revealed impaired working memory in a Y-maze test at 3 months of age and decreased locomotor activity in the home cage at 3 and 12 months of age in KI mice compared to those in wild-type mice. Although no obvious structural abnormalities were observed at 3 months of age, immunohistochemical studies showed elevation of Bsn immunoreactivity in the hippocampus and neuronal loss without tau accumulation in the substantia nigra at 12 months of age in KI mice. Although our mice model did not show progressive cognitive dysfunction and locomotor disorder like PSP-like syndrome, dopaminergic neuronal loss was observed in the substantia nigra in 12-month-old KI mice. It is possible that BSN mutation may result in dopaminergic neuronal loss without locomotor symptoms due to the early disease stage. Thus, further clinical course can induce cognitive dysfunction and locomotor symptoms.

Modulations of the mTORC2-GATA3 axis by an isorhamnetin activated endosomal-lysosomal system of the J774.1 macrophage-like cell line.

The endosomal-lysosomal system represents a crucial degradation pathway for various extracellular substances, and its dysfunction is linked to cardiovascular and neurodegenerative diseases. This degradation process involves multiple steps: (1) the uptake of extracellular molecules, (2) transport of cargos to lysosomes, and (3) digestion by lysosomal enzymes. While cellular uptake and lysosomal function are reportedly regulated by the mTORC1-TFEB axis, the key regulatory signal for cargo transport remains unclear. Notably, our previous study discovered that isorhamnetin, a dietary flavonoid, enhances endosomal-lysosomal proteolysis in the J774.1 cell line independently of the mTORC1-TFEB axis. This finding suggests the involvement of another signal in the mechanism of isorhamnetin. This study analyzes the molecular mechanism of isorhamnetin using transcriptome analysis and reveals that the transcription factor GATA3 plays a critical role in enhanced endosomal-lysosomal degradation. Our data also demonstrate that mTORC2 regulates GATA3 nuclear translocation, and the mTORC2-GATA3 axis alters endosomal formation and maturation, facilitating the efficient transport of cargos to lysosomes. This study suggests that the mTORC2-GATA3 axis might be a novel target for the degradation of abnormal substances.

RAB35 is required for murine hippocampal development and functions by regulating neuronal cell distribution.

RAB35 is a multifunctional small GTPase that regulates endocytic recycling, cytoskeletal rearrangement, and cytokinesis. However, its physiological functions in mammalian development remain unclear. Here, we generated Rab35-knockout mice and found that RAB35 is essential for early embryogenesis. Interestingly, brain-specific Rab35-knockout mice displayed severe defects in hippocampal lamination owing to impaired distribution of pyramidal neurons, although defects in cerebral cortex formation were not evident. In addition, Rab35-knockout mice exhibited defects in spatial memory and anxiety-related behaviors. Quantitative proteomics indicated that the loss of RAB35 significantly affected the levels of other RAB proteins associated with endocytic trafficking, as well as some neural cell adhesion molecules, such as contactin-2. Collectively, our findings revealed that RAB35 is required for precise neuronal distribution in the developing hippocampus by regulating the expression of cell adhesion molecules, thereby influencing spatial memory.

Proteomic profiling of intestinal epithelial-like cell-derived exosomes regulated by epigallocatechin gallate.

Exosomes are extracellular vesicles primarily responsible for intercellular communication, and they contain nucleic acids and proteins. Exosome secretion has been observed in the intestines, suggesting their physiological effects on the receptor cells of target tissues. It is possible that intestinal epithelial cells recognize food components as ligands, resulting in exosome secretion. However, research on intestine-derived exosomes regulated by food ingredients is limited. In this study, Caco-2 cells were utilized as an intestinal epithelial model for proteomic profiling. NanoLC-MS/MS analysis revealed the alteration of exosome properties by epigallocatechin gallate (EGCG) in differentiated Caco-2 cells. This natural polyphenol reduced both the number and size of secreted exosomes and altered the expression of exosomal proteins. The enriched proteins in exosomes were involved in immune response and cell proliferation. In contrast, those in the EGCG-treated group had distinctive functions in the maintenance of skin homeostasis. We also found variable expression of galectin-3-binding protein and fibronectin as molecular signatures in exosomes derived from EGCG-treated cells. These results could help elucidate the expression and mechanism of exosomal proteins related to food components.

Genome-Wide RNA Sequencing Analysis in Human Dermal Fibroblasts Exposed to Low-Dose Ultraviolet A Radiation.

Ultraviolet A (UVA) radiation can pass through the epidermis and reach the dermal skin layer, contributing to photoaging, DNA damage, and photocarcinogenesis in dermal fibroblasts. High-dose UVA exposure induces erythema, whereas low-dose, long-term UVA exposure causes skin damage and cell senescence. Biomarkers for evaluating damage caused by low-dose UVA in fibroblasts are lacking, making it difficult to develop therapeutic agents for skin aging and aging-associated diseases. We performed RNA-sequencing to investigate gene and pathway alterations in low-dose UVA-irradiated human skin-derived NB1RGB primary fibroblasts. Differentially expressed genes were identified and subjected to Gene Ontology and reactome pathway analysis, which revealed enrichment in genes in the senescence-associated secretory phenotype, apoptosis, respiratory electron transport, and transcriptional regulation by tumor suppressor p53 pathways. Insulin-like growth factor binding protein 7 (IGFBP7) showed the lowest p-value in RNA-sequencing analysis and was associated with the senescence-associated secretory phenotype. Protein-protein interaction analysis revealed that Fos proto-oncogene had a high-confidence network with IGFBP7 as transcription factor of the IGFBP7 gene among SASP hit genes, which were validated using RT-qPCR. Because of their high sensitivity to low-dose UVA radiation, Fos and IGFBP7 show potential as biomarkers for evaluating the effect of low-dose UVA radiation on dermal fibroblasts.

The use of an ultrasonic curettage device in orthognathic surgery decreases surgery-related blood loss.

Objective: This study aimed to compare the use of a powered instrument (PI) and ultrasonic curettage device (ULCD) with intraoperative blood loss (IOBL), drain volume (DV), calculated blood loss (CBL), and hidden blood loss (HBL) in orthognathic surgery. Methods: We included 163 patients who underwent bimaxillary surgery in our department. CBL was calculated from the preoperative and postoperative hemoglobin levels using the "hemoglobin balance method." CBL is an indicator of the amount of perioperative blood loss. HBL was calculated by subtracting IOBL and DV from CBL. Results: The PI group consisted of 61 patients (17 males and 44 females, age: 24.9 ± 9.5 years), and the ULCD group consisted of 102 patients (40 males and 62 females, age: 23.1 ± 7.8 years). In the PI group, the median IOBL, DV, CBL, and HBL were 540.0 (interquartile range [IQR] 380.0-670.0), 113.0 (IQR 77.0-147.0), 1000.0 (IQR 751.4-1248.6), and 285.8 (IQR 151.0-476.4) ml, respectively. In the ULCD group, the median IOBL, DV, CBL, and HBL were 327.5 (IQR 200.0-455.0), 105.5 (IQR 75.3-136.0), 759.5 (IQR 594.9-944.2), and 294.2 (IQR 120.8-456.9) ml, respectively. IOBL and CBL were significantly reduced with ULCD use, but no significant differences were observed in DV and HBL. Conclusions: This study showed that IOBL decreased with ULCD use, resulting in a decrease in CBL. Conversely, bleeding parameters (DV and HBL), which reflect the amount of bleeding that occurs after wound closure, did not show a decrease with ULCD use.

Hydrogen-rich water reduced oxidative stress and renal fibrosis in rats with unilateral ureteral obstruction.

BACKGROUND: Congenital obstructive nephropathy (CKD) is commonly implicated in the pathophysiology of chronic kidney disease occurring in the pediatric and adolescent age groups and the release of reactive oxygen species contribute to the worsening of renal fibrosis. Molecular hydrogen (H2) protects against tissue injury by reducing oxidative stress. We evaluated the efficacy of oral H2-rich water (HW) intake in preventing unilateral ureteral obstruction (UUO)-induced renal injury in rats. METHODS: Male Sprague-Dawley UUO or control rats were administered with distilled water (DW) or HW for 2 weeks post-surgery. Histopathological and immunohistochemical analyses of kidney samples were performed. RESULTS: Histological changes were not apparent in the sham-operated kidneys. However, UUO kidneys were found to have widened interstitial spaces and tubular dilatation. Compared with the UUO + DW group, HW administration attenuated tubulointerstitial injury and reduced interstitial fibrotic area, causing a substantial decline in the frequency of α-SMA-, ED-1-, and TGF-ß1-positive cells in the UUO + HW group. The decrease in the klotho mRNA expression in the UUO + HW group was less pronounced than that in the UUO + DW group. CONCLUSION: Oral HW intake reduced oxidative stress and prevented interstitial fibrosis in UUO kidneys, potentially involving klotho in the underlying mechanism. IMPACT: Oral intake of hydrogen-rich water (HW) can reduce oxidative stress and suppress interstitial fibrosis in unilateral ureteral obstruction-induced renal injury in rats. This mechanism possibly involves klotho, which is known for its antiaging roles. The association between molecular hydrogen and klotho in renal fibrosis is well known; this is the first report on the association in a unilateral ureteral obstruction model. Drinking HW is a safe and convenient treatment for oxidative stress-induced pathologies, without side effects. As a prospect for future research, oral HW intake to treat oxidative stress may improve renal fibrosis in congenital obstructive nephropathy.

Protective Effects of Hydrogen-rich Water Intake on Renal Injury in Neonatal Rats with High Oxygen Loading.

Objectives: This study aimed to investigate the protective effects of hydrogen-rich water (HW) intake on renal injury in neonatal rats with high oxygen loading. Materials: We used pregnant and newborn Sprague-Dawley rats. Methods: Four groups were set up, with mother and newborn rats immediately after delivery as one group: RA-PW (room air and purified water), RA-HW (room air and HW), O2-PW (80% oxygen and purified water), and O2-HW (80% oxygen and HW). The newborn rats were maintained in either a normoxic (room air, 21% oxygen) or controlled hyperoxic (80% oxygen) environment from birth. Then, HW (O2-HW and RA-HW groups) or PW (O2-PW and RA-PW groups) was administered to parents of each group. Results: The number of immature glomeruli significantly increased in the O2-PW group (exposed to hyperoxia). Conversely, the O2-HW group had significantly fewer immature glomeruli than O2-PW group. In the RT-PCR analysis of kidney tissue, α-SMA, TGF-ß, and TNF-α levels were significantly higher in the O2-PW group than in the RA-PW group and significantly lower in the O2-HW group than in the O2-PW group. Conclusions: HW intake can potentially reduce oxidative stress and prevent renal injury in neonates with high oxygen loading.

ZSWIM8 is a myogenic protein that partly prevents C2C12 differentiation.

Cell adhesion molecule-related/downregulated by oncogenes (Cdon) is a cell-surface receptor that mediates cell-cell interactions and positively regulates myogenesis. The cytoplasmic region of Cdon interacts with other proteins to form a Cdon/JLP/Bnip-2/CDC42 complex that activates p38 mitogen-activated protein kinase (MAPK) and induces myogenesis. However, Cdon complex may include other proteins during myogenesis. In this study, we found that Cullin 2-interacting protein zinc finger SWIM type containing 8 (ZSWIM8) ubiquitin ligase is induced during C2C12 differentiation and is included in the Cdon complex. We knocked-down Zswim8 in C2C12 cells to determine the effect of ZSWIM8 on differentiation. However, we detected neither ZSWIM8-dependent ubiquitination nor the degradation of Bnip2, Cdon, or JLP. In contrast, ZSWIM8 knockdown accelerated C2C12 differentiation. These results suggest that ZSWIM8 is a Cdon complex-included myogenic protein that prevents C2C12 differentiation without affecting the stability of Bnip2, Cdon, and JLP.

Electrolyzed Hydrogen Water Protects against Ethanol-Induced Cytotoxicity by Regulating Aldehyde Metabolism-Associated Enzymes in the Hepatic Cell Line HepG2.

Excessive alcohol consumption can cause multi-systemic diseases. Among them, alcoholic liver disease is the most frequent and serious disease. Electrolytic hydrogen water (EHW) is produced at the cathode during electrolysis of water and contains a large amount of molecular hydrogen and a low content of platinum nanoparticles with alkaline properties. In this study, we found that EHW inhibits ethanol-induced cytotoxicity by decreasing the intracellular acetaldehyde, a toxic substance produced by ethanol degradation, in hepatocyte cell lines HepG2. Analysis of the mechanism of action revealed that EHW inhibits the metabolism of ethanol to acetaldehyde by suppressing alcohol dehydrogenase. EHW also promotes the metabolism of acetaldehyde to acetic acid by activating aldehyde dehydrogenase, which plays to reduce aldehyde toxicity and intracellular reactive oxygen species in HepG2 cells. These functions were correlated with the concentration of molecular hydrogen in EHW, and were abolished by degassing treatment, suggesting that molecular hydrogen may contribute as a functional factor in the suppression of ethanol-induced hepatocellular damage. Furthermore, hydrogen water with high dissolved hydrogen molecule showed the same hepatocellular protective effect against ethanol as the EHW. These results suggest that EHW may be useful in the prevention of alcoholic liver disease.

Evaluating nocturnal polyuria in Japanese children with nocturnal enuresis.

BACKGROUND: The purpose of this study was to assess whether enuretic Japanese patients with nocturnal polyuria (NP) who met Hoashi's criteria (6-9 years: ≥200 mL; 10 years and older: ≥250 mL) met the International Children's Continence Society (ICCS; expected bladder capacity × 130%) and Rittig's criteria for nocturnal polyuria (>[age+9] × 20 mL). We also compared the effectiveness of 1-desamino-8-d-arginine vasopressin (DDAVP) with the three criteria. METHODS: Fifty-four patients who had NP with normal bladder capacity were enrolled: 36 boys (67%); median age, 8 (interquartile range: 7-9). We compared the diagnostic differences between the Hoashi's criteria and international standards (ICCS and Rittig's) for NP and the short-term effects of DDAVP. The patients received DDAVP for 8 weeks; we evaluated the association between each evaluation method and the effects of therapy. RESULTS: Only 17% of the patients met both Hoashi's and ICCS criteria, whereas 26% met both Hoashi's and Rittig's criteria. The therapeutic effect of DDAVP did not differ significantly between these two groups: there was an effective rate of 73% (Hoashi's criteria) versus 50% (ICCS criteria), P = 0.19, and an effective rate of 71% (Hoashi's criteria) versus 62% (Rittig's criteria), P = 0.84. CONCLUSIONS: Hoashi's criteria are widely used but, according to both the ICCS and Rittig's criteria, approximately 80% of the patients did not fulfill the definition of NP. However, 8 weeks after the DDAVP treatment began, no significant difference was observed in the therapeutic effect of DDAVP according to each set of criteria. The definition of NP should account for the physical disparities between Japanese people and Westerners.

Identification of Dietary Phytochemicals Capable of Enhancing the Autophagy Flux in HeLa and Caco-2 Human Cell Lines.

Autophagy is a major degradation system for intracellular macromolecules. Its decline with age or obesity is related to the onset and development of various intractable diseases. Although dietary phytochemicals are expected to enhance autophagy for preventive medicine, few studies have addressed their effects on the autophagy flux, which is the focus of the current study. Herein, 67 dietary phytochemicals were screened using a green fluorescent protein (GFP)-microtubule-associated protein light chain 3 (LC3)-red fluorescent protein (RFP)-LC3ΔG probe for the quantitative assessment of autophagic degradation. Among them, isorhamnetin, chrysoeriol, 2,2',4'-trihydroxychalcone, and zerumbone enhanced the autophagy flux in HeLa cells. Meanwhile, analysis of the structure-activity relationships indicated that the 3'-methoxy-4'-hydroxy group on the B-ring in the flavone skeleton and an ortho-phenolic group on the chalcone B-ring were crucial for phytochemicals activities. These active compounds were also effective in colon carcinoma Caco-2 cells, and some of them increased the expression of p62 protein, a typical substrate of autophagic proteolysis, indicating that phytochemicals impact p62 levels in autophagy-dependent and/or -independent manners. In addition, these compounds were characterized by distinct modes of action. While isorhamnetin and chrysoeriol enhanced autophagy in an mTOR signaling-dependent manner, the actions of 2,2',4'-trihydroxychalcone and zerumbone were independent of mTOR signaling. Hence, these dietary phytochemicals may prove effective as potential preventive or therapeutic strategies for lifestyle-related diseases.

Bilberry Anthocyanins Ameliorate NAFLD by Improving Dyslipidemia and Gut Microbiome Dysbiosis.

Non-alcoholic fatty liver disease (NAFLD) is a manifestation of metabolic syndrome closely linked to dyslipidemia and gut microbiome dysbiosis. Bilberry anthocyanins (BA) have been reported to have preventive effects against metabolic syndrome. This study aimed to investigate the protective effects and mechanisms of BA in a Western diet (WD)-induced mouse model. The results revealed that supplementation with BA attenuated the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), low-density lipoprotein cholesterol (LDL-c), fat content in liver, 2-thiobarbituric acid reactive substances (TBARS) and α-smooth muscle actin (α-SMA) caused by WD. Furthermore, gut microbiota characterized by 16S rRNA sequencing revealed that BA reduced remarkably the ratio of Firmicutes/Bacteroidetes (F/B) and modified gut microbiome. In particular, BA increased the relative abundance of g_Akkermansia and g_Parabacteroides. Taken together, our data demonstrated that BA might ameliorate WD-induced NAFLD by attenuating dyslipidemia and gut microbiome dysbiosis.

High-Fat Diet Enhances Working Memory in the Y-Maze Test in Male C57BL/6J Mice with Less Anxiety in the Elevated Plus Maze Test.

Obesity is characterized by massive adipose tissue accumulation and is associated with psychiatric disorders and cognitive impairment in human and animal models. However, it is unclear whether high-fat diet (HFD)-induced obesity presents a risk of psychiatric disorders and cognitive impairment. To examine this question, we conducted systematic behavioral analyses in C57BL/6J mice (male, 8-week-old) fed an HFD for 7 weeks. C57BL/6J mice fed an HFD showed significantly increased body weight, hyperlocomotion in the open-field test (OFT) and Y-maze test (YMZT), and impaired sucrose preference in the sucrose consumption test, compared to mice fed a normal diet. Neither body weight nor body weight gain was associated with any of the behavioral traits we examined. Working memory, as assessed by the YMZT, and anxiety-like behavior, as assessed by the elevated plus maze test (EPMT), were significantly correlated with mice fed an HFD, although these behavioral traits did not affect the entire group. These results suggest that HFD-induced obesity does not induce neuropsychiatric symptoms in C57BL/6J mice. Rather, HFD improved working memory in C57BL/6J mice with less anxiety, indicating that an HFD might be beneficial under limited conditions. Correlation analysis of individual traits is a useful tool to determine those conditions.

Isorhamnetin, a 3'-methoxylated flavonol, enhances the lysosomal proteolysis in J774.1 murine macrophages in a TFEB-independent manner.

Lysosome is the principal organelle for the ultimate degradation of cellular macromolecules, which are delivered through endocytosis, phagocytosis, and autophagy. The lysosomal functions have been found to be impaired by fatty foods and aging, and more importantly, the lysosomal dysfunction in macrophages has been reported as a risk of atherosclerosis development. In this study, we searched for dietary polyphenols which possess the activity for enhancing the lysosomal degradation in J774.1, a murine macrophage-like cell line. Screening test utilizing DQ-BSA digestion identified isorhamnetin (3'-O-methylquercetin) as an active compound. Interestingly, structural comparison to inactive flavonols revealed that the chemical structure of the B-ring moiety in isorhamnetin is the primary determinant of its lysosome-enhancing activity. Unexpectedly isorhamnetin failed to inhibit mTORC1-TFEB signaling, a master regulator of lysosomal biogenesis and function. Our data suggested that the other molecular mechanism might be critical for the regulation of lysosomes in macrophages.Abbreviations: ANOVA: analysis of variance; ApoE: apolipoprotein E; ATP6V0D2: ATPase H+ transporting V0 subunit d2; BAF: bafilomycin A1; BODIPY: boron dipyrromethene; BSA: bovine serum albumin; CTSD: cathepsin D; CTSF: cathepsin F; DMEM: Dulbecco's modified eagle medium; DMSO: dimethyl sulfoxide; EGCG: epigallocatechin-3-gallate; FBS: fetal bovine serum; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HPLC: high-performance liquid chromatography; LAMP1: lysosomal-associated membrane protein 1; LAMP2A: lysosomal-associated membrane protein 2A; LC-MS/MS: liquid chromatography tandem mass spectrometry; MITF: microphthalmia-associated transcription factor; MRM: multiple reaction monitoring; mTORC1: mechanistic target of rapamycin complex 1; PBS: phosphate-buffered saline; PPARγ: peroxisome proliferator-activated receptor γ; RT-qPCR: reverse transcription quantitative polymerase chain reaction; SDS: sodium dodecyl sulfate; SNARE: soluble N-ethylmaleimide-sensitive-factor attachment protein receptor; TBS: Tris-buffered saline; TFA: trifluoroacetic acid; TFE3: transcription factor binding to IGHM enhancer 3; TFEB: transcriptional factor EB; TFEC: transcription factor EC; V-ATPase: vacuolar-type proton ATPase.

Clinical Effects and Outcomes After Polymyxin B-Immobilized Fiber Column Direct Hemoperfusion Treatment for Septic Shock in Preterm Neonates.

OBJECTIVES: To compare the effectiveness and mortality of early-onset sepsis or late-onset sepsis treatments with polymyxin B-immobilized fiber column direct hemoperfusion in terms of effectiveness and mortality in preterm infants with septic shock. DESIGN: Retrospective cohort study. SETTING: Neonatal ICU within a tertiary care hospital. PATIENTS: Of 1,115 patients, 49 had blood culture-proven sepsis between January 2013 and December 2018; six and five patients with septic shock had undergone polymyxin B-immobilized fiber column direct hemoperfusion treatment for early-onset sepsis (early-onset sepsis group) and late-onset sepsis (late-onset sepsis group), respectively. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Baseline demographic characteristics of both groups were similar. The time from decision to treatment induction was significantly shorter in the early-onset sepsis group than that in the late-onset sepsis group (p = 0.008). The mortality rate after 28 days of treatment and the hospital mortality were significantly lower in the early-onset sepsis group than in the late-onset sepsis group (p = 0.026 and 0.015, respectively). The PaO2/FIO2 ratio was significantly higher in the early-onset sepsis group than in the late-onset sepsis group at the end of the treatment (p = 0.035). In addition, median arterial-to-alveolar oxygen tension ratio significantly improved from 0.19 to 0.55, and median blood pressure also significantly improved from 32.5 to 40.0 mm Hg after the treatment in the early-onset sepsis group. Interleukin-6 levels significantly decreased after treatment in the early-onset sepsis group (p = 0.037). The Pediatric Risk of Mortality III score was similar between the early-onset sepsis and late-onset sepsis groups before and after the treatment. Intraventricular hemorrhage events occurred in both groups, but with no significant differences (p = 0.175). CONCLUSIONS: Polymyxin B-immobilized fiber column direct hemoperfusion treatment for preterm infants with septic shock due to early-onset sepsis is associated with earlier hemodynamic and respiratory status improvements and with lower mortality than that due to late-onset sepsis. Early neonatal septic shock detection and polymyxin B-immobilized fiber column direct hemoperfusion induction may improve the prognosis of affected infants.

Urinary angiotensinogen in pediatric urinary tract infection.

BACKGROUND: Urinary tract infection (UTI) is one of the most common diseases in children, and urinary angiotensinogen (U-AGT) is a new biomarker gathering attention in many renal diseases. U-AGT reflects intrarenal renin-angiotensin system (RAS) activity. We conducted a study to measure U-AGT in children <4 months old with UTI. METHODS: All children <4 months old who came to Toshima Hospital with fever between January 2015 and December 2015 were included. Patients were divided into a UTI group and a non-UTI group, and U-AGT was measured. RESULTS: Median U-AGT was higher in patients with UTI compared with patients without UTI: (0.56 ng/dL, range, 0.025-2.753 ng/dL vs 0.13 ng/dL, range, 0.008-1.697 ng/dL, respectively; P < 0.05). CONCLUSIONS: U-AGT is elevated in UTI patients, and RAS activation may contribute to renal injury caused by UTI.

Rer1-mediated quality control system is required for neural stem cell maintenance during cerebral cortex development.

Rer1 is a retrieval receptor for endoplasmic reticulum (ER) retention of various ER membrane proteins and unassembled or immature components of membrane protein complexes. However, its physiological functions during mammalian development remain unclear. This study aimed to investigate the role of Rer1-mediated quality control system in mammalian development. We show that Rer1 is required for the sufficient cell surface expression and activity of γ-secretase complex, which modulates Notch signaling during mouse cerebral cortex development. When Rer1 was depleted in the mouse cerebral cortex, the number of neural stem cells decreased significantly, and malformation of the cerebral cortex was observed. Rer1 loss reduced γ-secretase activity and downregulated Notch signaling in the developing cerebral cortex. In Rer1-deficient cells, a subpopulation of γ-secretase complexes and components was transported to and degraded in lysosomes, thereby significantly reducing the amount of γ-secretase complex on the cell surface. These results suggest that Rer1 maintains Notch signaling by maintaining sufficient expression of the γ-secretase complex on the cell surface and regulating neural stem cell maintenance during cerebral cortex development.

Mutations in COA7 cause spinocerebellar ataxia with axonal neuropathy.

Several genes related to mitochondrial functions have been identified as causative genes of neuropathy or ataxia. Cytochrome c oxidase assembly factor 7 (COA7) may have a role in assembling mitochondrial respiratory chain complexes that function in oxidative phosphorylation. Here we identified four unrelated patients with recessive mutations in COA7 among a Japanese case series of 1396 patients with Charcot-Marie-Tooth disease (CMT) or other inherited peripheral neuropathies, including complex forms of CMT. We also found that all four patients had characteristic neurological features of peripheral neuropathy and ataxia with cerebellar atrophy, and some patients showed leukoencephalopathy or spinal cord atrophy on MRI scans. Validated mutations were located at highly conserved residues among different species and segregated with the disease in each family. Nerve conduction studies showed axonal sensorimotor neuropathy. Sural nerve biopsies showed chronic axonal degeneration with a marked loss of large and medium myelinated fibres. An immunohistochemical assay with an anti-COA7 antibody in the sural nerve from the control patient showed the positive expression of COA7 in the cytoplasm of Schwann cells. We also observed mildly elevated serum creatine kinase levels in all patients and the presence of a few ragged-red fibres and some cytochrome c oxidase-negative fibres in a muscle biopsy obtained from one patient, which was suggestive of subclinical mitochondrial myopathy. Mitochondrial respiratory chain enzyme assay in skin fibroblasts from the three patients showed a definitive decrease in complex I or complex IV. Immunocytochemical analysis of subcellular localization in HeLa cells indicated that mutant COA7 proteins as well as wild-type COA7 were localized in mitochondria, which suggests that mutant COA7 does not affect the mitochondrial recruitment and may affect the stability or localization of COA7 interaction partners in the mitochondria. In addition, Drosophila COA7 (dCOA7) knockdown models showed rough eye phenotype, reduced lifespan, impaired locomotive ability and shortened synaptic branches of motor neurons. Our results suggest that loss-of-function COA7 mutation is responsible for the phenotype of the presented patients, and this new entity of disease would be referred to as spinocerebellar ataxia with axonal neuropathy type 3.

SFT-4/Surf4 control ER export of soluble cargo proteins and participate in ER exit site organization.

Lipoproteins regulate the overall lipid homeostasis in animals. However, the molecular mechanisms underlying lipoprotein trafficking remain poorly understood. Here, we show that SFT-4, a Caenorhabditis elegans homologue of the yeast Erv29p, is essential for the endoplasmic reticulum (ER) export of the yolk protein VIT-2, which is synthesized as a lipoprotein complex. SFT-4 loss strongly inhibits the ER exit of yolk proteins and certain soluble cargo proteins in intestinal cells. SFT-4 predominantly localizes at ER exit sites (ERES) and physically interacts with VIT-2 in vivo, which suggests that SFT-4 promotes the ER export of soluble proteins as a cargo receptor. Notably, Surf4, a mammalian SFT-4 homologue, physically interacts with apolipoprotein B, a very-low-density lipoprotein core protein, and its loss causes ER accumulation of apolipoprotein B in human hepatic HepG2 cells. Interestingly, loss of SFT-4 and Surf4 reduced the number of COPII-positive ERES. Thus, SFT-4 and Surf4 regulate the export of soluble proteins, including lipoproteins, from the ER and participate in ERES organization in animals.