Browsing by Subject "HAIR"

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  • Lamnidis, Thiseas C.; Majander, Kerttu; Jeong, Choongwon; Salmela, Elina; Wessman, Anna; Moiseyev, Vyacheslav; Khartanovich, Valery; Balanovsky, Oleg; Ongyerth, Matthias; Weihmann, Antje; Sajantila, Antti; Kelso, Janet; Pääbo, Svante; Onkamo, Päivi; Haak, Wolfgang; Krause, Johannes; Schiffels, Stephan (2018)
    European population history has been shaped by migrations of people, and their subsequent admixture. Recently, ancient DNA has brought new insights into European migration events linked to the advent of agriculture, and possibly to the spread of Indo-European languages. However, little is known about the ancient population history of north-eastern Europe, in particular about populations speaking Uralic languages, such as Finns and Saami. Here we analyse ancient genomic data from 11 individuals from Finland and north-western Russia. We show that the genetic makeup of northern Europe was shaped by migrations from Siberia that began at least 3500 years ago. This Siberian ancestry was subsequently admixed into many modern populations in the region, particularly into populations speaking Uralic languages today. Additionally, we show that ancestors of modern Saami inhabited a larger territory during the Iron Age, which adds to the historical and linguistic information about the population history of Finland.
  • Cooper, Rory L.; Lloyd, Victoria J.; Di-Poï, Nicolas; Fletcher, Alexander G.; Barrett, Paul M.; Fraser, Gareth J. (2019)
    Vertebrates possess a diverse range of integumentary epithelial appendages, including scales, feathers and hair. These structures share extensive early developmental homology, as they mostly originate from a conserved anatomical placode. In the context of avian epithelial appendages, feathers and scutate scales are known to develop from an anatomical placode. However, our understanding of avian reticulate (footpad) scale development remains unclear.
  • Kuony, Alison; Ikkala, Kaisa; Kalha, Solja; Magalhaes, Ana Cathia; Pirttiniemi, Anniina; Michon, Frederic (2019)
    A lack of ectodysplasin-A (Eda) signaling leads to dry eye symptoms, which have so far only been associated with altered Meibomian glands. Here, we used loss-of-function (Eda(-/-)) mutant mice to unravel the impact of Eda signaling on lacrimal gland formation, maturation and subsequent physiological function. Our study demonstrates that Eda activity is dispensable during lacrimal gland embryonic development. However, using a transcriptomic approach, we show that the Eda pathway is necessary for proper cell terminal differentiation in lacrimal gland epithelium and correlated with modified expression of secreted factors commonly found in the tear film. Finally, we discovered that lacrimal glands present a bilateral reduction of Eda signaling activity in response to unilateral comeal injury. This observation hints towards a role for the Eda pathway in controlling the switch from basal to reflex tears, to support corneal wound healing. Collectively, our data suggest a crucial implication of Eda signaling in the comea-lacrimal gland feedback loop, both in physiological and pathophysiological conditions. Our findings demonstrate that Eda downstream targets could help alleviate dry eye symptoms.
  • Mogollon, Isabel; Ahtiainen, Laura (2020)
    Embryonic development of ectodermal organs involves a very dynamic range of cellular events and, therefore, requires advanced techniques to visualize them. Ectodermal organogenesis proceeds in well-defined sequential stages mediated by tissue interactions. Different ectodermal organs feature shared morphological characteristics, which are regulated by conserved and reiterative signaling pathways. A wealth of genetic information on the expression patterns and interactions of specific signaling pathways has accumulated over the years. However, the conventional developmental biology methods have mainly relied on two-dimensional tissue histological analyses at fixed time points limiting the possibilities to follow the processes in real time on a single cell resolution. This has complicated the interpretation of cause and effect relationships and mechanisms of the successive events. Whole-mount tissue live imaging approaches are now revealing how reshaping of the epithelial sheet for the initial placodal thickening, budding morphogenesis and beyond, involve coordinated four dimensional changes in cell shapes, well-orchestrated cell movements and specific cell proliferation and apoptosis patterns. It is becoming evident that the interpretation of the reiterative morphogenic signals takes place dynamically at the cellular level. Depending on the context, location, and timing they drive different cell fate choices and cellular interactions regulating a pattern of behaviors that ultimately defines organ shapes and sizes. Here we review how new tissue models, advances in 3D and live tissue imaging techniques have brought new understanding on the cell level behaviors that contribute to the highly dynamic stages of morphogenesis in teeth, hair and related ectodermal organs during development, and in dysplasia contexts.
  • Ferone, Giustina; Thomason, Helen A.; Antonini, Dario; De Rosa, Laura; Hu, Bing; Gemei, Marica; Zhou, Huiqing; Ambrosio, Raffaele; Rice, David P.; Acampora, Dario; van Bokhoven, Hans; Del Vecchio, Luigi; Koster, Maranke I.; Tadini, Gianluca; Spencer-Dene, Bradley; Dixon, Michael; Dixon, Jill; Missero, Caterina (2012)
  • Saito, Kan; Michon, Frederic; Yamada, Aya; Inuzuka, Hiroyuki; Yamaguchi, Satoko; Fukumoto, Emiko; Yoshizaki, Keigo; Nakamura, Takashi; Arakaki, Makiko; Chiba, Yuta; Ishikawa, Masaki; Okano, Hideyuki; Thesleff, Irma; Fukumoto, Satoshi (2020)
    The transcription factor Sox21 is expressed in the epithelium of developing teeth. The present study aimed to determine the role of Sox21 in tooth development. We found that disruption of Sox21 caused severe enamel hypoplasia, regional osteoporosis, and ectopic hair formation in the gingiva in Sox21 knockout incisors. Differentiation markers were lost in ameloblasts, which formed hair follicles expressing hair keratins. Molecular analysis and chromatin immunoprecipitation sequencing indicated that Sox21 regulated Anapc10, which recognizes substrates for ubiquitination-mediated degradation, and determined dental-epithelial versus hair follicle cell fate. Disruption of either Sox21 or Anapc10 induced Smad3 expression, accelerated TGF-beta 1-induced promotion of epithelial-to-mesenchymal transition (EMT), and resulted in E-cadherin degradation via Skp2. We conclude that Sox21 disruption in the dental epithelium leads to the formation of a unique microenvironment promoting hair formation and that Sox21 controls dental epithelial differentiation and enamel formation by inhibiting EMT via Anapc10.
  • Kriikku, Pirkko; Pelander, Anna; Rasanen, Ilpo; Ojanperä, Ilkka (2019)
    U-47,700 is a synthetic opioid that emerged on the novel psychoactive substance market a few years ago. After incorporating the substance into the urine UPLC-TOF-MS screening used in post-mortem toxicology, the drug was detected in 10 autopsy cases within routine case work. In all cases, the cause of death was accidental poisoning by U-47,700 alone or in combination with other psychoactive substances. The concentration of U-47,700 in the blood samples ranged between 0.15-2.0 mg/L with a median of 0.30 mg/L. In one of the cases with a U-47,700 concentration of 0.27 mg/L, no other psychoactive substances were detected. The stored TOF-MS analytical data from the year preceding the incorporation of U-47,700 into the screening was reprocessed in order to search for more positive cases. The data-independent acquisition of the original screening allowed for retrospective re-analysis of the full-scan data without additional experiments on the actual sample. The retrospective data-analysis revealed two additional cases positive for U-47,700. The first mention of U-47,700 on a Finnish internet discussion forum was in March 2015. After having been detected in several death cases, the drug was put under national control in November 2016 and the last fatality occurred in 2017. The toxic lifespan of U-47,700 thus lasted for approximately 2 years in Finland. Forensic and clinical laboratories need to rapidly adjust their screening procedures in order to adapt to the continuously expanding field of novel psychoactive substances. Retrospective data-analysis is a practical tool for monitoring the emergence of new substances onto the market. (C) 2019 Elsevier B.V. All rights reserved.