The molecular basis for genetic polymorphism of human deoxyribonuclease I: identification of the nucleotide substitution that generates the fourth allele

AbstractIn addition to the three alleles commonly responsible for the protein polymorphism of human deoxyribonuclease I, a mutation encoded by a fourth allele, DNASEI*4, was detected by isoelectric focusing. All 8 exons covering the entire open reading frame of the human DNase I gene were amplified by the polymerase chain reaction and subjected to direct sequencing. Only one nucleotide substitution, a C-to-G transition (CAG → GAG), in the codon for amino acid 9 of the mature enzyme was found. This substitution resulted in the replacement of Gln with Glu (Q9E)

Expression and localization of aquaporin 1b during oocyte development in the Japanese eel (Anguilla japonica)

To elucidate the molecular mechanisms underling hydration during oocyte maturation, we characterized the structure of Japanese eel (Anguilla japonica) novel-water selective aquaporin 1 (AQP1b) that thought to be involved in oocyte hydration. The aqp1b cDNA encodes a 263 amino acid protein that includes the six potential transmembrane domains and two Asn-Pro-Ala motifs. Reverse transcription-polymerase chain reaction showed transcription of Japanese eel aqp1b in ovary and testis but not in the other tissues. In situ hybridization studies with the eel aqp1b cRNA probe revealed intense eel aqp1b signal in the oocytes at the perinucleolus stage and the signals became faint during the process of oocyte development. Light microscopic immunocytochemical analysis of ovary revealed that the Japanese eel AQP1b was expressed in the cytoplasm around the yolk globules which were located in the peripheral region of oocytes during the primary yolk globule stage; thereafter, the immunoreactivity was observed throughout the cytoplasm of oocyte as vitellogenesis progressed. The immunoreactivity became localized around the large membrane-limited yolk masses which were formed by the fusion of yolk globules during the oocyte maturation phase. These results together indicate that AQP1b, which is synthesized in the oocyte during the process of oocyte growth, is essential for mediating water uptake into eel oocytes

Diphenhydramine against cisplatin nephrotoxicity

Cisplatin is widely used as an anti-tumor drug for the treatment of solid tumors. Unfortunately, it causes nephrotoxicity as a critical side effect, limiting its use, given that no preventive drug against cisplatin-induced nephrotoxicity is currently available. This study identified that a previously developed drug, diphenhydramine, may provide a novel treatment for cisplatin-induced nephrotoxicity based on the results of the analysis of medical big data. We evaluated the actual efficacy of diphenhydramine via in vitro and in vivo experiments in a mouse model. Diphenhydramine inhibited cisplatin-induced cell death in renal proximal tubular cells. Mice administered cisplatin developed kidney injury with renal dysfunction (plasma creatinine: 0.43 ± 0.04 mg/dl vs 0.15 ± 0.01 mg/dl, p<0.01) and showed augmented oxidative stress, increased apoptosis, elevated inflammatory cytokines, and mitogen-activated protein kinases activation; however, most of these symptoms were suppressed by treatment with diphenhydramine. Further, the renal concentration of cisplatin was attenuated in diphenhydramine-treated mice (platinum content: 70.0 ± 3.3 µg/g dry kidney weight vs 53.4 ± 3.6 µg/g dry kidney weight, p<0.05). Importantly, diphenhydramine did not influence or interfere with the anti-tumor effect of cisplatin in any of the in vitro or in vivo experiments. Moreover, a retrospective clinical study of 1467 cancer patients treated with cisplatin showed that patients who had used diphenhydramine exhibited less acute kidney injury than patients who had not used diphenhydramine (6.1 % vs 22.4 %, p<0.05). Thus, diphenhydramine demonstrated efficacy as a novel preventive medicine against cisplatin-induced nephrotoxicity

Inhibitory action of iron on erythropoietin via oxidative stress-HIF-2α pathway

Renal anemia is a major complication in chronic kidney disease (CKD). Iron supplementation, as well as erythropoiesis-stimulating agents, are widely used for treatment of renal anemia. However, excess iron causes oxidative stress via the Fenton reaction, and iron supplementation might damage remnant renal function including erythropoietin (EPO) production in CKD. EPO gene expression was suppressed in mice following direct iron treatment. Hypoxia-inducible factor-2 alpha (HIF-2α), a positive regulator of the EPO gene, was also diminished in the kidney of mice following iron treatment. Anemia-induced increase in EPO and HIF-2α expression was also inhibited by iron-treatment. In in vitro experiments using EPO-producing HepG2 cells, iron stimulation reduced the expression of the EPO gene, as well as HIF-2α. Moreover, iron treatment augmented oxidative stress, and iron-induced reduction of EPO and HIF-2α expression was restored by tempol, an anti-oxidant compound. HIF-2α interaction with the EPO promoter was inhibited by iron treatment, and was restored by tempol. These findings suggested that iron supplementation reduced EPO gene expression via an oxidative stress-HIF-2α-dependent signaling pathway

Dietary iron restriction alleviates renal tubulointerstitial injury induced by protein overload in mice

Increased proteinuria causes tubulointerstitial injury due to inflammation in chronic kidney disease (CKD). Iron restriction exhibits protective effects against renal dysfunction; however, its effects against protein overload-induced tubulointerstitial damage remain unclear. Here, we investigated dietary iron restriction effect on tubulointerstitial damage in mice with protein-overload tubulointerstitial injury. Renal tubulointerstitial injury in animal model was induced by intraperitoneal injection of an overdose of bovine serum albumin (BSA). We divided mice into three groups: normal saline + normal diet (ND), BSA + ND, and BSA + iron-restricted diet (IRD). BSA overload induced renal tubulointerstitial injury in the ND mice, which was ameliorated in the IRD mice. Inflammatory cytokines and extracellular matrix mRNA expression was upregulated in BSA + ND mice kidneys and was inhibited by IRD. BSA-induced increase in renal superoxide production, NADPH oxidase activity, and p22phox expression was diminished in the IRD mice. IRD suppression increased BSA-induced renal macrophage infiltration. Moreover, BSA mice exhibited nucleotide-binding oligomerisation domain-like receptor pyrin domain-containing protein (NLRP) inflammasome activation, which was inhibited by IRD. Ferrous iron increased in kidneys with BSA overload and was inhibited by IRD. Thus, iron restriction inhibited oxidative stress and inflammatory changes, contributing to the protective effect against BSA overload-induced tubulointerstitial injury

Structural basis for channel conduction in the pump-like channelrhodopsin ChRmine

新規光駆動型イオンチャネルの構造解明と高性能分子ツールの創出 --神経科学に光を当てる--. 京都大学プレスリリース. 2022-02-03.ChRmine, a recently discovered pump-like cation-conducting channelrhodopsin, exhibits puzzling properties (large photocurrents, red-shifted spectrum, and extreme light sensitivity) that have created new opportunities in optogenetics. ChRmine and its homologs function as ion channels but, by primary sequence, more closely resemble ion pump rhodopsins; mechanisms for passive channel conduction in this family have remained mysterious. Here, we present the 2.0 Å resolution cryo-EM structure of ChRmine, revealing architectural features atypical for channelrhodopsins: trimeric assembly, a short transmembrane-helix 3, a twisting extracellular-loop 1, large vestibules within the monomer, and an opening at the trimer interface. We applied this structure to design three proteins (rsChRmine and hsChRmine, conferring further red-shifted and high-speed properties, respectively, and frChRmine, combining faster and more red-shifted performance) suitable for fundamental neuroscience opportunities. These results illuminate the conduction and gating of pump-like channelrhodopsins and point the way toward further structure-guided creation of channelrhodopsins for applications across biology

Epidemiological and clinical features of lung cancer patients from 1999 to 2009 in Tokushima Prefecture of Japan

Lung cancer is the leading cause of malignancy-related death worldwide. In the present study, we reviewed the epidemiologic and clinical features of lung cancer in Tokushima Prefecture, Japan. Between January 1999 and December 2009, 2,183 patients with lung cancer were enrolled in this study. One thousand five hundred ninety-one (73%) patients were male and 592 (27%) patients were female. Median age was 70 years, with a range of 15-93 years. Seventy-six percent of patients had smoking history. One thousand nine hundred five (87%) patients were non-small cell lung cancer and the predominant histological type was adenocarcinoma (51%). Among all 2,183 patients, 702 (32%) belonged to elderly population. Four hundred seventy-one (22%), 213 (10%), 24 (1%), 116 (5%), 238 (11%), 370 (17%) and 678 (31%) patients had stage IA, IB, IIA, IIB, IIIA, IIIB and IV lung cancer, respectively. In Tokushima University Hospital, 516 (29%), 191 (11%), 58 (3%), 755 (43%) and 216 (12%) patients were initially treated with chemotherapy, chemo-radiotherapy, thoracic radiotherapy, operation and best supportive care, respectively. The median time to progression (TTP) and the median survival time (MST) of patients treated with chemotherapy and chemo-radiotherapy were 3.5 months, 13.0 months and 7.0 months, 18.0 months, respectively. The median TTP and the MST of 33 elderly patients treated with chemotherapy were 3.3 months and 18.0 months, respectively, which were comparable with those of total population. These results indicated the benefit of chemotherapy in elderly patients with advanced lung cancer by proper selection

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection