ras Mutations in Endocrine Tumors : Mutation Detection by Polymerase Chain Reaction‐Single Strand Conformation Polymorphism

To elucidate the molecular basis for endocrine tumorigenesis, ras mutations in human endocrine tumors were analyzed using polymerase chain reaction‐single strand conformation polymorphism (PCR‐SSCP) analysis. Mutations of the H‐, K‐, N‐ras genes were examined in genomic DNAs from 169 successfully amplified primary endocrine tumors out of 189 samples. Four out of 24 thyroid follicular adenomas analyzed contained mutated N‐ras codon 61, and one contained the mutated H‐ras codon 61. One of the 19 pheochromocytomas revealed mutation of the H‐ras codon 13. No mutations of the ras gene were detected in pituitary adenomas, parathyroid tumors, thyroid cancers, endocrine pancreatic tumors, and adrenocortical tumors. Based on these findings we conclude that activation of the ras gene may play a role in the tumorigenesis of a limited number of thyroid follicular adenomas and pheochromocytomas, and that mutation of the ras gene is not frequent in other human endocrine tumors

Iodine containing porous organosilica nanoparticles trigger tumor spheroids destruction upon monochromatic X-ray irradiation: DNA breaks and K-edge energy X-ray

アインシュタインの光電効果をがん細胞の中で再現　放射線治療への新展開. 京都大学プレスリリース. 2021-07-14.Quantum physics helps destroy cancer cells. 京都大学プレスリリース. 2021-07-14.X-ray irradiation of high Z elements causes photoelectric effects that include the release of Auger electrons that can induce localized DNA breaks. We have previously established a tumor spheroid-based assay that used gadolinium containing mesoporous silica nanoparticles and synchrotron-generated monochromatic X-rays. In this work, we focused on iodine and synthesized iodine-containing porous organosilica (IPO) nanoparticles. IPO were loaded onto tumor spheroids and the spheroids were irradiated with 33.2 keV monochromatic X-ray. After incubation in CO₂ incubator, destruction of tumor spheroids was observed which was accompanied by apoptosis induction, as determined by the TUNEL assay. By employing the γH2AX assay, we detected double strand DNA cleavages immediately after the irradiation. These results suggest that IPO first generate double strand DNA breaks upon X-ray irradiation followed by apoptosis induction of cancer cells. Use of three different monochromatic X-rays having energy levels of 33.0, 33.2 and 33.4 keV as well as X-rays with 0.1 keV energy intervals showed that the optimum effect of all three events (spheroid destruction, apoptosis induction and generation of double strand DNA breaks) occurred with a 33.2 keV monochromatic X-ray. These results uncover the preferential effect of K-edge energy X-ray for tumor spheroid destruction mediated by iodine containing nanoparticles

Omega-3 Polyunsaturated Fatty Acids Suppress the Cystic Lesion Formation of Peritoneal Endometriosis in Transgenic Mouse Models

Omega-3 polyunsaturated fatty acids (omega-3 PUFAs) play a role in controlling pathological inflammatory reactions. Endometriosis is characterized by the presence of endometrial tissue on the peritoneum and an exaggerated inflammatory environment around ectopic tissues. Here peritoneal endometriosis was reproduced using a mouse model in which murine endometrial fragments were inoculated into the peritoneal cavity of mice. Fat-1 mice, in which omega-6 can be converted to omega-3 PUFAs, or wild type mice, in which it cannot, were used for the endometriosis model to address the actions of omega-3 PUFAs on the development of endometriotic lesions. The number and weight of cystic endometriotic lesions in fat-1 mice two weeks after inoculation were significantly less than half to those of controls. Mediator lipidomics revealed that cystic endometriotic lesions and peritoneal fluids were abundant in 12/15-hydroxyeicosapentaenoic acid (12/15-HEPE), derived from eicosapentaenoic acid (EPA), and their amount in fat-1 mice was significantly larger than that in controls. 12/15-Lipoxygenase (12/15-LOX)-knockout (KO) and control mice with or without EPA administration were assessed for the endometriosis model. EPA administration decreased the number of lesions in controls but not in 12/15-LOX-KO mice. The peritoneal fluids in EPA-fed 12/15-LOX-KO mice contained reduced levels of EPA metabolites such as 12/15-HEPE and EPA-derived resolvin E3 even after EPA administration. cDNA microarrays of endometriotic lesions revealed that Interleukin-6 (IL-6) expression in fat-1 mice was significantly lower than that in controls. These results suggest that both endogenous and exogenous EPA-derived PUFAs protect against the development of endometriosis through their anti-inflammatory effects and, in particular, the 12/15-LOX-pathway products of EPA may be key mediators to suppress endometriosis

Increased tissue levels of omega-3 polyunsaturated fatty acids prevents pathological preterm birth

Omega-3 polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) have anti-inflammatory effects. Preterm birth is an important problem in modern obstetrics and one of the main causes is an inflammation. We here showed that abundance of omega-3 fatty acids reduced the incidence of preterm birth induced by LPS with fat-1 mice, capable of converting omega-6 to omega-3 fatty acids. We also indicated that the gene expression of IL-6 and IL-1β in uteruses and the number of cervical infiltrating macrophages were reduced in fat-1 mice. The analyses of lipid metabolomics showed the high level of 18-hydroxyeicosapentaenoate in fat-1 mice, which was derived from EPA and was metabolized to anti-inflammatory product named resolvin E3 (RvE3). We finally showed that the administration of RvE3 to LPS-exposed pregnant wild type mice lowered the incidence of preterm birth. Our data suggest that RvE3 could be a potential new therapeutic for the prevention of preterm birth

Chondroitin sulfate N-acetylgalactosaminyltransferase-1 is required for normal cartilage development

CS (chondroitin sulfate) is a glycosaminoglycan species that is widely distributed in the extracellular matrix. To understand the physiological roles of enzymes involved in CS synthesis, we produced CSGalNAcT1 (CS N-acetylgalactosaminyltransferase 1)-null mice. CS production was reduced by approximately half in CSGalNAcT1-null mice, and the amount of short-chain CS was also reduced. Moreover, the cartilage of the null mice was significantly smaller than that of wild-type mice. Additionally, type-II collagen fibres in developing cartilage were abnormally aggregated and disarranged in the homozygous mutant mice. These results suggest that CSGalNAcT1 is required for normal CS production in developing cartilage

Larval pufferfish protected by maternal tetrodotoxin

Marine pufferfish contain tetrodotoxin (TTX), an extremely potent neurotoxin. All species of the genus Takifugu accumulate TTX in the liver and ovaries, although the tissue(s) in which it is localized can differ among species. TTX is the major defense strategy the pufferfish appears to use against predators. TTX is also used as a male-attracting pheromone during spawning. Here we demonstrate an additional (and unexpected) use of maternal TTX in the early larval stages of the Takifugu pufferfish. Predation experiments demonstrated that juveniles of all the species of fish used as predators ingested pufferfish larvae, but spat them out promptly. Liquid Chromatography-Tandem Mass Spectrometry (LC-MSMS) analysis revealed that the pufferfish larvae contain a small quantity of TTX, which is not enough to be lethal to the predators. Immunohistochemical analysis with anti-TTX monoclonal antibody revealed that the TTX is primarily localized in the body surface of the larvae as a layer of protection. Our study showed the female parent of the Takifugu pufferfish vertically transfers TTX to the larvae through its accumulation in the ovaries, and subsequent localization on the body surface of the larvae

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

ニホン ニ テイチャク シタ トガリアメンボ ノ シュウネン ケイカ ト ラン キュウミン

トガリアメンボは和歌山県北部および大阪府南部において卵態で越冬することを明らかにした。当該地域において, 本種の成虫は一般に6月上旬から11月下旬まで水面上で活動し, 10月以降には休眠卵を産出した。野外で越冬した卵の孵化時期は不斉一であり, 翌年の4月下旬から5月中旬に孵化した。休眠卵は1か月以上の5℃暴露および2時間の-5℃暴露に耐性を有していた。非休眠卵の卵期間は20℃で約27日, 25℃で約19日, 28℃で約15日であり, 発育は斉一であった。幼虫期間は日長と無関係で, 20℃で約62日, 25℃で約38日, 28℃で約32日であった。有翅型成虫は6月から11月まで出現した。野外における本種の産卵基質には水面上に浮遊する植物片が利用されており, 樹皮断片, および長さ35mm以下で直径2～4mm の枝片に特に多く産卵されることが明らかになった。また, 室内では, 一部の卵は産卵基質に挿入されず水中に放出された。これらにも正常に発育して水中から孵化するもののあることを認めた。In northern Wakayama and southern Osaka areas on Honshu Island, it was confirmed that the waterstrider Rhagadotarsus kraepelini Breddin overwinters as eggs. Adults generally appeared on ponds from early June to late November. Alate adults were observed from June through to November, and diapausing eggs were produced from October onwards. Hatching of these diapausing eggs under field conditions occurred between late April and mid-May of the following year. Diapausing eggs that were exposed to 5℃ for 41 days and then chilled to -5℃ for a further 2 hours were able to complete their hatching when returned to an incubation temperature of 25℃. Duration from oviposition to hatching in non-diapausing eggs was approximately 27 days when incubated at 20℃, 19 days at 25℃, and 15 days at 28℃. Developmental times in nymphs decreased as incubation temperatures increased, and were unaffected by photoperiod. In field populations, floating plant materials such as bits of bark and short twigs were used as ovipositional substances. In laboratory rearing trials, a small proportion of eggs were also deposited in the water and had become fixed to the bottom of the container. Some of these eggs successfully hatched

In situ synchrotron radiation observation of deformation and annealing processes of aluminum single crystal

本研究では、SPring-8の放射光単色X線を利用し、アルミニウム単結晶の変形と焼きなまし過程におけるその場測定を実施した。測定試料はブリッジマン法によって育成した、長手方向に平行な方位を持つアルミニウム単結晶である。この試料をインライン高温引張負荷装置を利用し、室温で公称8%ひずみまで引張変形を与え、変形後、同装置を用いて753.15 Kで焼きなましを行った。変形、および、焼きなまし中の試料からの複数の回折スポットを、二次元検出器によってその場観察を行った。変形前後の過程において、アルミニウム単結晶粒内は、3つの亜結晶領域に分かれていることが明らかになった。さらに、回折スポットを1次元化して求めた回折プロファイルの時間変化を観察したところ、引張ひずみが増加するにつれ、亜結晶ごとに分かれていたピークプロファイルの強度が減少し、幅が広がっていく、いわゆる転位微細構造へ変化していく過程が明らかになった。変形後の焼きなましでは、温度が753.15 Kに達してから180秒後に再結晶した結晶粒からの回折スポットが初めて出現した。変形母材と再結晶粒からの回折スポットが共存する状態は、照射体積内で22秒程度しか続かなかった。また、変形母材と再結晶粒の境界の移動速度は、毎秒数マイクロメートルのオーダーであると推定された