Systemic mastocytosis is a rare disease involving the infiltration and accumulation of active mast cells within any organ system. By far, the most common organ affected is the skin. Cutaneous manifestations of mastocytosis, including Urticaria Pigmentosa (UP), cutaneous mastocytoma or telangiectasia macularis eruptive perstans (TMEP), may indicate a more serious and potentially life-threatening underlying disease. The presence of either UP or TMEP in a patient with anaphylactic symptoms should suggest the likelihood of systemic mastocytosis, with the caveat that systemic complications are more likely to occur in patients with UP. TMEP can usually be identified by the typical morphology, but a skin biopsy is confirmative. In patients with elevated tryptase levels or those with frequent systemic manifestations, a bone marrow biopsy is essential in order to demonstrate mast cell infiltration. Further genetic testing for mutations of c-kit gene or the FIP1L1 gene may help with disease classification and/or therapeutic approaches. Rarely, TMEP has been described with malignancy, radiation therapy, and myeloproliferative disorders. A few familial cases have also been described. In this review, we discuss the clinical features, diagnosis and management of patients with TMEP. We also discuss the possible molecular pathogenesis and the role of genetics in disease classification and treatment.

Nucleotide excision repair (NER) and ataxia telangiectasia mutated (ATM)/ATR (ATM- and RAD3-related) NA damage checkpoints are among the major pathways that affect the chemotherapeutic efficiency of the anticancer rug cisplatin. Xeroderma pigmentosum group A (XPA) protein plays a crucial role in NER including both global enome repair (GG-NER) and transcription-coupled repair (TC-NER) subpathways, and has been a potential target for mproving cisplatin therapeutic effects. We report here that XPA translocates from the cytosol into the nucleus after NA damage induced by UV irradiation and cisplatin, a mimetic of UV damage, in human cells with or without p53 deficiency. However, the damage-induced response of XPA nuclear import was significantly slower in p53-deficient cells than in p53-proficient cells. We also found that while XPA is imported into the nucleus upon cisplatin or UV damage in an ATR-dependent manner in p53-proficient A549 lung cancer cells, the ATR checkpoint pathway has no effect on the XPA nuclear import in p53-deficient H1299 lung cancer cells. Similarly, the XPA nuclear translocation is not regulated by ATM checkpoint or by p38MAPK/MK2 either. Our findings suggest that NER is independent on the major DNA damage checkpoint pathways in H1299 (p53-/-) cells and that DNA damage responses are mechanistically different between p53-proficient and p53-deficient cells. Our results also highlight the possibility of selectively targeting XPA nuclear import as a way to sensitize cisplatin anticancer activity, but targeting ATR/ATM-dependent checkpoints may not be helpful in killing p53-deficient cancer cells.

Ataxia telangiectasia mutated kinase (ATM) is activated in response to DNA damage. We have previously shown that ATM plays a critical role in myocyte apoptosis and cardiac remodeling after myocardial infarction (MI). Here, we tested the hypothesis that ATM deficiency results in autophagic impairment in the heart early during MI. MI was induced in wild-type (WT) and ATM heterozygous knockout (hKO) mice by ligation of the left anterior descending artery. Structural and biochemical parameters of the heart were measured 4 h after left anterior descending artery ligation. M-mode echocardiography revealed that MI worsens heart function, as evidenced by reduced percent ejection fraction and fractional shortening in both groups. However, MI-induced increase in left ventricular end-diastolic and end-systolic diameters and volumes were significantly lower in hKO hearts. ATM deficiency resulted in autophagic impairment during MI, as evidenced by decreased microtubule-associated protein light chain 3-II increased p62, decreased cathepsin D protein levels, and increased aggresome accumulation. ERK1/2 activation was only observed in WT-MI hearts. Activation of Akt and AMP-activated protein kinase (AMPK) was lower, whereas activation of glycogen synthase kinase (GSK)-3β and mammalian target of rapamycin (mTOR) was higher in hKO-MI hearts. Inhibition of ATM using KU-55933 resulted in autophagic impairment in cardiac fibroblasts, as evidenced by decreased light chain 3-II protein levels and formation of acidic vesicular organelles. This impairment was associated with decreased activation of Akt and AMPK but enhanced activation of GSK-3 β and mTOR in KU-55933-treated fibroblasts. Thus, ATM deficiency results in autophagic impairment in the heart during MI and cardiac fibroblasts. This autophagic impairment may occur via the activation of GSK-3 β and mTOR and inactivation of Akt and AMPK. NEW & NOTEWORTHY Ataxia telangiectasia mutated kinase (ATM) plays a critical role in myocyte apoptosis and cardiac remodeling after myocardial infarction (MI). Here, we provide evidence that ATM deficiency results in autophagic impairment during MI. Further investigation of the role of ATM in autophagy post-MI may provide novel therapeutic targets for patients with ataxia telangiectasia suffering from heart disease.

Ataxia-telangiectasia mutated kinase (ATM) is a serine/threonine kinase. Mutations in the ATM gene cause a rare autosomal multisystemic disease known as Ataxia-telangiectasia (AT). Individuals with mutations in both copies of the ATM gene suffer from increased susceptibility to ionizing radiation, predisposition to cancer, insulin resistance, immune deficiency, and premature aging. Patients with one mutated allele make-up ~1.4 to 2% of the general population. These individuals are spared from most of the symptoms of the disease. However, they are predisposed to developing cancer or ischemic heart disease, and die 7-8 years earlier than the non-carriers. DNA double-strand breaks activate ATM, and active ATM is known to phosphorylate an extensive array of proteins involved in cell cycle arrest, DNA repair, and apoptosis. The importance of ATM in the regulation of DNA damage response signaling is fairly well-established. This review summarizes the role of ATM in the heart, specifically in cardiac remodeling following β-adrenergic receptor stimulation and myocardial infarction.

Neutrophile sind Zellen des Immunsystems von Säugetieren. Ihre zerstörerische Kraft spielt eine essentielle Rolle bei der Bekämpfung von Mikroorganismen, birgt aber auch das Potential erheblicher Kollateralschäden. Um chronische Entzündungen zu vermeiden, müssen diese Zellen streng reguliert werden. Die Neutrophilen selber nehmen an dieser Regulierung durch das Freisetzen von pro- und antiinflammatorischen Signalen Teil, unter anderem produzieren sie Zytokine oder initiieren rechtzeitig die Apoptose. Ein Eckpfeiler der Regulierung dieser Funktionen ist der oxidative Burst, bei dem Neutrophile reaktive Sauerstoffspezies (ROS) bilden. Die molekularen Ziele von ROS, welche diese Mechanismen regulieren, sind nicht alle identifiziert. Wir haben ataxia-telangiectasia mutated (ATM) Kinase, ein Regulator der DNA-Schadensantwort (DDR), als einen ROS-abhängigen Modulator von Neutrophilen identifiziert. Mutationen in ATM führen zu der Erkrankung Ataxia Telangiectasia (AT). AT Patienten leiden nicht nur unter den Folgen der fehlerhaften DNA-Reparatur sondern zeigen auch inflammationsassoziierte Krankheitserscheinigungen. Diese Beobachtung veranlasste uns, die Neutrophilen von AT Patienten genauer zu untersuchen. Wir zeigen, dass Neutrophile von AT Patienten erhöhte Menge an Zytokinen produzieren und Apoptose verzögern. Wir zeigen auch, dass DNA Schaden die Zytokinproduktion unterdrückt und Apoptose durch einen Mechanismus, der ATM, p38, und Chk2 verwendet initiiert. ROS sind notwendig für die endogene Regulierung dieser Prozesse. Diese Arbeit enthüllt einen neuartigen Mechanismus der Regulierung von Neutrophilen und etabliert die DDR als ein Ziel der ROS-gesteuerten Immunmodulation. Im Zusammenhang wird auch gezeigt, dass dysregulierte Neutrophilenaktivitäten einem inflammatorischen Phänotyp in AT zugrundeliegen könnte. Wir glauben, dass Entzündung eine treibende Kraft hinter Teilen der Pathologie von AT sein könnte und somit ein Ziel für klinische Intervention darstellt. / Neutrophils are cells of the mammalian innate immune system whose inflammatory functions are essential for microbial clearance but cause collateral tissue damage. Inflammation is regulated by both pro- and anti-inflammatory signals, including cytokine production and initiation of apoptosis. A cornerstone of the regulation of these functions is the oxidative burst, by which neutrophils generate reactive oxygen species (ROS). The downstream targets of ROS responsible for regulating these functions are not fully identified. We have identified ataxia telangiectasia mutated (ATM) kinase, a master regulator of the DNA damage response (DDR), as a ROS-dependent modulator of neutrophil responses. Mutations in ATM cause the disease Ataxia-telangiectasia (AT). In addition to disorders resulting from defective DNA repair, AT patients suffer from symptoms linked to inflammation, leading us to examine their neutrophil responses. We report that neutrophils from AT patients overproduce pro-inflammatory cytokines and delay apoptosis. We further show that DNA damage in neutrophils suppresses cytokine production and can initiate apoptosis via a mechanism involving ATM, p38, and Chk2. Furthermore, the oxidative burst was required for activation of ATM to regulate these processes.. This work reveals a novel mechanism for the regulation of neutrophil functions, establishing the DDR as a mediator of immune regulation by ROS. Furthermore, it indicates that neutrophil dysregulation may underlie chronic inflammation in AT patients. We propose that inflammation may be a driving force behind some of the pathology of AT, providing a potential target for clinical intervention for some symptoms of this currently untreatable disease.

Venous disease is a common vascular condition affecting the lower limbs and causes considerable morbidity in affected patients. National Health Service (NHS) treatment costs are substantial and there is a large demand for treatment much of which cannot be met. Roughly half a million people in the United Kingdom contact their general practitioner each year about varicose veins and associated clinical symptoms. In order to assign priorities and target interventions properly, authorities need to know which patients with venous disease will progress. Although many epidemiological studies have investigated the prevalence of venous disease, information on deterioration is scarce. The overall aim of this study is to determine the natural history of venous disease in the population and to identify lifestyle and clinical factors related to deterioration which might aid clinical decision making and health services policy. The specific objectives were to determine which risk factors were associated with deterioration of venous disease and venous reflux, and to ascertain the natural history of asymptomatic venous incompetence in terms of deteriorating to overt trunk varicose veins and chronic venous insufficiency. The study design was a population based cohort in the Edinburgh Vein Study which the survivors of the 1566 individuals aged 18 to 64 randomly sampled years from the general population at baseline underwent a 13-year follow-up examination. Details of the 1566 participants in the baseline study were sent to the Practitioner Services Division (PSD) of the NHS in Scotland who provided updated addresses and general practitioner registration details. Information collected on each subject at a follow-up clinic included lifestyle factors and medical history, height and weight measurement (by means of a questionnaire), clinical examination for classification of venous disease according to the Basle and CEAP systems, and duplex scanning to assess incompetence of venous valves in the deep and superficial systems of ten vein segments in each leg. Of the subjects from the baseline, 880 participated in the follow-up study, and 576 did not participate, providing a response rate of 60.4% of which 490 were female (55.7%) and 390 were male (44.3%). The study subjects were generally older and slightly more affluent than residents of the City of Edinburgh. For trunk varicose veins, the baseline prevalence was higher in males compared to females (p<0.01), but there was no difference in prevalence among subjects at the follow-up stage of the study (p=0.56). The overall rate of deterioration in trunk varicose veins was 3.55% per annum. More females than males deteriorated (p=0.04). Among subjects who showed deterioration in their trunk varicose veins, the commonest deterioration was from Basle Grade I (mild) at baseline to Grade II (moderate) at follow-up in both the right and left leg (28.1% and 32.9% respectively). Subjects older than 55 years of age (OR=1.59, 95% CI 1.01-2.51), who had a positive family history of varicose veins or venous ulcer (OR=1.92, 95% CI 1.20-3.07), and sat down at work for more than half the working day (OR=1.69, 95% CI 1.04-2.73) had increased risk of deteriorating trunk varicose veins. There was no significant difference between males and females in the prevalence of chronic venous insufficiency (CVI) among subjects at both the baseline and follow-up stage of the study (p=0.15 and 0.16 respectively). The rate of deterioration in CVI was 1.76% per annum. Similarly, among subjects who deteriorated, the commonest deterioration was from Grade I (mild) to Grade II (moderate) CEAP classification in both the right and left leg (42.4% and 45.5% respectively). The risk of worsening of CVI among those older than 55 was nearly three times more than those aged less than 55 (OR=2.85, 95% CI 1.18-6.87), and was still significant when adjusted for gender. The prevalence of telangiectasia was higher in females than in males in both the baseline and follow-up stages of the study (both p<0.01). The rate of deterioration in telangiectasia was 1.6% per annum. The commonest deterioration was from grade I (mild) at baseline to grade II (moderate) follow-up in the left and right leg (using the Basle Classification). Females subjects (OR=1.87, 95% CI 1.35-2.64), those older than 55 (OR=1.68, 95% CI 1.19-2.36), with a positive family history of venous disease (OR=1.60 95% CI 1.14-2.24) were associated with an increased risk of deterioration from telangiectasia compared to male subjects under 55 years of age and with no family history of the disease. The risk of telangiectasia deterioration was more than twice as high in subjects with venous reflux in the greater saphenous vein (origin) (OR=2.34, 95% CI 1.53-3.57), the greater saphenous vein (lower third of the thigh) (OR=2.28, 95% CI 1.59-3.27) and in the small saphenous vein (1.89, 95% CI 1.06-3.36) compared to those with no segments affected. The age and gender adjusted risk was also more than twice as high in subjects with venous reflux in two segments of the superficial system compared to subjects with no venous reflux in any segment (OR=2.06, 95% CI 1.23-3.44), and almost four times as high in subjects with reflux in more than three segments of the superficial system (OR=3.97, 95% CI 2.16-7.31) compared to subjects with no segments affected. On duplex scanning, the prevalence of reflux was higher in females than in males in the superficial system at baseline and follow-up stages of the study (p<0.01 respectively). In the deep system, the prevalence was higher in males than females at the baseline stage (p<0.01) with no significant difference at the follow-up stage (p=0.85). The rate of deterioration in venous reflux was 1.28% per annum. Most subjects deteriorated from one to two vein segments affected in the leg, the majority of which had reflux in the greater saphenous vein (thigh) at baseline and developed reflux in the greater saphenous vein (origin) at follow-up. Subjects more than 55 years of age had significantly more deterioration than those aged less than 55 (p<0.01). Obese or overweight subjects (OR=1.59, 95% CI 1.32-3.67), those aged more than 55 (OR=2.20, 95% CI 1.32-3.67), with a family history of varicose veins (among female subjects only, OR=2.55, 95% CI 1.16-5.56), and who sat down at work more than half the working time (among male subjects only) (OR=2.26, 95%CI 0.97-5.23) had increased risk of showing deterioration in reflux in any leg and in any vein segment from baseline to follow-up. Subjects with venous reflux at baseline were over two and half times more likely to show deterioration in trunk varicose veins compared to those with no reflux (OR=2.69, 95%CI 1.44-5.01), and four times more likely to deteriorate in either trunk varicose veins or chronic venous insufficiency (OR=4.20, 95% CI 2.42-7.29). Subjects with venous reflux at baseline were twice as likely to develop new trunk varicose veins (OR=2.08, 95%CI 1.25-3.46), and 1.78 times more likely to develop either trunk varicose veins or chronic venous insufficiency (OR=1.78, 95%CI 1.12-2.80). Age and gender adjusted risk of trunk varicose veins increased more than fourfold among subjects with venous reflux in the greater saphenous veins (OR=4.04, 95% CI 2.36-6.92), and more than threefold in the greater saphenous vein (lower third of the thigh) (OR=3.13, 95% CI 1.85-5.27) and the small saphenous vein (OR=3.17, 95% CI 1.55-6.48). Subjects with venous reflux in two or more than three vein segments in the superficial system were more than five times more likely to deteriorate from trunk varicose veins (OR=5.39, 95% CI 2.64-10.99 and OR=5.96, 95% CI 2.71-13.10 respectively). The Edinburgh Vein Study follow-up identified factors linked to deterioration of trunk varicose veins and CVI. The findings of this follow-up study have important implications in decision making in NHS and a prognostic tool could be produced to assist clinicians in deciding who should receive treatment or maintained under surveillance. Increasing age, and family history will likely lead to worsening of trunk varicose veins and CVI. The findings also confirm the association between asymptomatic and symptomatic venous valvular incompetence with worsening and developing new cases of venous disease. Such information will be essential for policy makers facing difficult decisions over prioritisation of services in the future. Further research might include trials of surgical and non-surgical interventions designed to limit deterioration in high risk individuals and enable surgeons to target interventions appropriately. Larger prognostic studies of many factors, including genotype, might be conducted to link progression of venous disease, and to provide further information on high risk individuals who might benefit from treatment.

La télangiectasie hémorragique héréditaire (HHT) est une maladie rare (1/10.000). Son incidence est plus élevée (pouvant atteindre 1/1000) dans certaines zones géographiques dont la région Poitou-Charentes. Cette maladie autosomique dominante est causée par des mutations d'un des trois gènes identifiés ENG, ACVRL1 et SMAD4 codant pour des protéines de la voie BMP spécifiquement exprimés dans les cellules endothéliales. Le nombre croissant de mutations détectées chez les patients et l'expressivité variable de certaines mutations nous a ammené à déterminer les conséquences de mutations afin d'établir une corrélation génotype/phénotype. Cette corrélation est importante pour le conseil génétique et évidemment le diagnostic prénatal. Dans ce contexte, nous avons étudié aux niveaux cellulaire et moléculaire les effets de plusieurs mutations. L'effet délétère de ces mutations sur la protéine et/ou l'épissage de l'ARN a été évalué. Nous avons montré que sur les 23 mutations d'ACVRL1 : 1) 18 mutations faux-sens affectent la fonctionnalité de la protéine en réponse à BMP9 et 3 mutations sont de simples polymorphismes, 2) la mutation exonique c.733A>G (p.Ile245Val) affecte l'épissage de l'exon 6, 3) La mutation c.1048+5G>A de l'intron 7 en dehors du site consensus induit un épissage aberrant de l'exon 7. En ce qui concerne l'ENG, nous avons analysé 4 mutations et nous avons montré que la mutation c.1088G>A (p.Cys363Tyr) a un impact sur l'activité du récepteur et que les mutations c.1134G>A (p.Ala378Ala) et c.1060C>T (p.Leu364Leu) altèrent l'épissage de l'exon 8. Ce travail montre l'importance de l'étude approfondie de toute nouvelle mutation par des études in silico, in vitro et in cellulo à différents niveaux cellulaires. Des études in vivo ultérieures peuvent compléter et appuyer la stratégie expérimentale que nous avons suivie. / Hereditary hemorrhagic telangiectasia (HHT) is a rare disease (1/10.000). Its incidence is higher in certain geographic areas including the Poitou-Charentes region (1/1000). This autosomal dominant disease is caused by mutations in one of three identified genes ENG, ACVRL1 and SMAD4 encoding BMP pathway proteins specially expressed in endothelial cells. The increasing number of mutations detected in patients and the variable expressivity of certain mutations has taken us to determine the consequences of mutations to establish a genotype/phenotype correlation. This correlation is important for genetic counseling and obviously for prenatal diagnosis. In this context, we investigated the effects of several mutations at the cellular and molecular levels. The deleterious impact of these mutations on the protein and/or RNA splicing was evaluated. We have shown that for the 23 mutations of ACVRL1: 1) 18 missense mutations affect the functionality of the protein in response to BMP9 and 3 are polymorphisms, 2) exonic mutation c.733A>G (p. Ile245Val) affects the splicing of the exon 6, 3) mutation c.1048+5G>A in intron 7 off the consensus site induces an aberrant splicing of exon 7. Concerning the ENG, we analyzed 4 mutations and we showed that the mutation c.1088G> A (p.Cys363Tyr) has an impact on the activity of the receptor and that the mutations c.1134G> A (p.Ala378Ala) and c.1060C> T (p.Leu364Leu) inhibit the splicing of exon 8. This work shows the importance of the comprehensive study of any new mutation by in silico, in vitro and in cellulo studies at different cellular levels. The in vivo studies can further complement and support the experimental strategy that we followed.

付記する学位プログラム名: 充実した健康長寿社会を築く総合医療開発リーダー育成プログラム / 京都大学 / 新制・課程博士 / 博士(医学) / 甲第24520号 / 医博第4962号 / 新制||医||1065(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 生田 宏一, 教授 万代 昌紀, 教授 松田 文彦 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 新制・課程博士 / 博士(生命科学) / 甲第24753号 / 生博第494号 / 新制||生||66(附属図書館) / 京都大学大学院生命科学研究科統合生命科学専攻 / (主査)教授 片山 高嶺, 教授 高田 穣, 教授 原田 浩 / 学位規則第4条第1項該当 / Doctor of Philosophy in Life Sciences / Kyoto University / DFAM

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