The influence of high temperature on the possibility of DNA typing in various human tissues

Introduction. The identification of unknown victims of high temperatures (fire, terrorist attack, and other disasters) is one of the most difficult tasks faced by forensic geneticists. The main aim of this study was to in­vestigate the availability of DNA isolated from various human tissue samples exposed to high temperatures of 100–1000°C for 5 and 10 minutes. Material and methods. Samples of varying thickness of thigh muscle, liver, heart, adipose tissue, bone, teeth, hair and nails of 52 fresh cadavers and 59 healthy teeth of 29 volunteers were used. The study was performed using the following commercially available STR (Short Tandem Repeats) and miniSTR kits: AmpFlSTR®SGM Plus® and AmpFlSTR®MiniFilerTM. Hyper variable region I (HVI) of human mitochondrial DNA (mtDNA) was sequenced with BigDye Terminator Cycle Sequencing Kit 1.1. The PEP (Primer-Extension Preamplification) method was used for the whole human genome amplification. Results. It was possible to obtain complete DNA profiles (AmpFlSTR®SGM Plus®, AmpFlSTR®MiniFilerTM Applied Biosystems, USA and mtDNA HVI region) for tissue samples of heart, liver and thigh muscle, exposed up to 900°C for 5 min. However, under the applied conditions, limited usefulness of hair, nails and teeth for identification purposes was shown. Conclusions. DNA stability in tissues subjected to incineration depends on many factors, like tissue type and its thickness, temperature and time of exposure. In the cases of human remains exposed to high temperatures, samples of soft tissues of the highest weight (thickness) provide the best chance of successful identification through the genetic analysis. In some cases of negative results, even if using mtDNA typing, application of the whole genome amplification (WGA) technique could provide the expected results for highly degraded DNA templates

CSF1R Stimulation Promotes Increased Neuroprotection by CD11c+ Microglia in EAE

Microglia are resident immune cells of the central nervous system. Their development and maintenance depend on stimulation of Colony Stimulating Factor-1 receptor (CSF1R). Microglia play an important role in neurodevelopment and a population of microglia that expresses the complement receptor CD11c is critical for primary myelination. This population is virtually absent in the healthy adult brain but increases dramatically upon neuroinflammatory conditions, and these microglia are suggested to play a protective role in central nervous system (CNS) diseases. To date, the molecular trigger for their expansion is unknown. Here we showed that stimulation of CSF1R by either of its ligands, CSF1 and interleukin (IL)-34, can induce expansion of CD11c+ microglia. In addition, such stimulation resulted in amelioration of EAE symptoms and decreased demyelination. Treatment with CSF1R ligands also induced expression of the chemokine CCL2, and we showed that experimental overexpression of CCL2 in the brain led to a dramatic increase of CD11c+ microglia, independent of CCR2. Moreover, this led to elevated CSF1 expression, suggesting a positive feedback loop between CSF1R and CCL2. These data provide new insights to microglia biology and open new perspectives for modulating microglial activity in neuroinflammatory diseases such as multiple sclerosis

DNA structures decorated with cathepsin G/secretory leukocyte proteinase inhibitor stimulate IFNI production by plasmacytoid dendritic cells

Plasmacytoid dendritic cells (pDCs) and neutrophils are detected in psoriatic skin lesions and implicated in the pathogenesis of psoriasis. pDCs specialize in the production of type I interferon (IFNI), a cytokine that plays an important role in chronic autoimmune-like inflammation, including psoriasis. Here, we demonstrate that IFNI production in pDCs is stimulated by DNA structures containing the neutrophil serine protease cathepsin G (CatG) and the secretory leukocyte protease inhibitor (SLPI), which is a controlling inhibitor of serine proteases. We also demonstrate the presence of neutrophil-derived DNA structures containing CatG and SLPI in lesional skin samples from psoriasis patients. These findings suggest a previously unappreciated role for CatG in psoriasis by linking CatG and its inhibitor SLPI to the IFNI-dependent regulation of immune responses by pDCs in psoriatic skin

Type I interferon-activated microglia are critical for neuromyelitis optica pathology

Neuromyelitis optica (NMO) is an inflammatory disease of the central nervous system (CNS) most frequently mediated by serum autoantibodies against the water channel aquaporin 4, expressed on CNS astrocytes, resulting in primary astrocytopathy. There is no cure for NMO, and treatment with Type I interferon (IFNI)-IFN beta is ineffective or even detrimental. We have previously shown that both NMO lesions and associated microglial activation were reduced in mice lacking the receptor for IFN beta. However, the role of microglia in NMO is not well understood. In this study, we clarify the pathomechanism for IFNI dependence of and the role of microglia in experimental NMO. Transcriptome analysis showed a strong IFNI footprint in affected CNS tissue as well as in microglial subpopulations. Treatment with IFN beta led to exacerbated pathology and further microglial activation as evidenced by expansion of a CD11c(+) subset of microglia. Importantly, depletion of microglia led to suppression of pathology and decrease of IFNI signature genes. Our data show a pro-pathologic role for IFNI-activated microglia in NMO and open new perspectives for microglia-targeted therapies

Microglia-Secreted Factors Enhance Dopaminergic Differentiation of Tissue- and iPSC-Derived Human Neural Stem Cells

In this article, Schmidt and colleagues show that differentiating human NSCs in co-culture with microglia enhance dopaminergic differentiation. The effect is consistent across different NSC and microglial cell lines but restricted to microglia of embryonic origin. TNFα, IL-1β, and IGF1 are identified as key mediators of the effect, providing new insights into factors stimulating dopaminergic differentiation.Microglia have recently been established as key regulators of brain development. However, their role in neuronal subtype specification remains largely unknown. Using three different co-culture setups, we show that microglia-secreted factors enhance dopaminergic differentiation of somatic and induced pluripotent stem cell-derived human neural stem cells (NSCs). The effect was consistent across different NSC and microglial cell lines and was independent of prior microglial activation, although restricted to microglia of embryonic origin. We provide evidence that the effect is mediated through reduced cell proliferation and decreased apoptosis and necrosis orchestrated in a sequential manner during the differentiation process. tumor necrosis factor alpha, interleukin-1β, and insulinlike growth factor 1 are identified as key mediators of the effect and shown to directly increase dopaminergic differentiation of human NSCs. These findings demonstrate a positive effect of microglia on dopaminergic neurogenesis and may provide new insights into inductive and protective factors that can stimulate in vitro derivation of dopaminergic neurons.Innovation Fund Denmark (BrainStem; www.brainstem.dk), the Lundbeck Foundation, the Danish Parkinson Foundation, the Jascha Foundation, IMK Almene Fond, the A.P. Møller Foundation, and the Faculty of Health Sciences, University of Southern Denmar

Physical and dynamical properties of the unusual V-type asteroid (2579) Spartacus

Context. Asteroid (2579) Spartacus is a small V-type object located in the inner main belt. This object shows spectral characteristics unusual for typical Vestoids, which may indicate an origin deeper than average within Vesta or an origin from an altogether different parent body. Aims. Our main goal is to study the origin of Spartacus. We derive the spin of Spartacus and a convex shape model of Spartacus in order to increase the knowledge of the body's physical properties. The rotational parameters are then used to investigate dynamical evolution of the object as well as to distinguish regions sampled by spectral observations to determine whether its surface displays heterogeneity. Methods. We collected lightcurves available from the literature (oppositions of 2009, 2012) and obtained additional photometric observations at various telescopes in 2016, 2017, and 2018. We used the lightcurve inversion method to derive a spin and convex shape model. We have collected spectral observations over two rotational periods of Spartacus and determined its spectral parameters using the modified Gaussian model (MGM). We then dynamically integrated the orbital elements of Spartacus, taking into account existing information, including its thermal properties, size and the derived spin axis orientation. Results. We find two models for (2579) Spartacus: (a) lambda = 312 degrees +/- 5 degrees, beta = -57 degrees +/- 5 degrees and (b) lambda = 113 degrees +/- 5 degrees, beta = -60 degrees +/- 5 degrees both retrograde. We find that the drift direction for Spartacus is consistent with separation from Vesta, and after a backward integration of 1 Gyr the asteroid reaches the boundary of the family. We did not observe spectral variations with rotation, thus the body most likely has a homogeneous surface. Additionally, new spectral analysis indicates that the 1.0 and 2.0 mu m band centers are within ranges that are typical for Vestoids while the area ratio of these bands is about half that of typical Vestoids. Conclusions. The asteroid (2579) Spartacus is in retrograde rotation and has a drift direction consistent with an origin from Vesta. The revised spectral band centers are within ranges typical for Vestoids, while band area ratio (BAR) is unusually low compared to that of other V-types. The dynamical model shows that the asteroid could have migrated to its current location from the edges of the Vesta family within 1 Gyr, but an origin from an earlier impact on Vesta could also be plausible.Peer reviewe

A novel microglial subset plays a key role in myelinogenesis in developing brain

Microglia are resident macrophages of the central nervous system that contribute to homeostasis and neuroinflammation. Although known to play an important role in brain development, their exact function has not been fully described. Here, we show that in contrast to healthy adult and inflammation-activated cells, neonatal microglia show a unique myelinogenic and neurogenic phenotype. A CD11c(+) microglial subset that predominates in primary myelinating areas of the developing brain expresses genes for neuronal and glial survival, migration, and differentiation. These cells are the major source of insulin-like growth factor 1, and its selective depletion from CD11c(+) microglia leads to impairment of primary myelination. CD11c-targeted toxin regimens induced a selective transcriptional response in neonates, distinct from adult microglia. CD11c(+) microglia are also found in clusters of repopulating microglia after experimental ablation and in neuroinflammation in adult mice, but despite some similarities, they do not recapitulate neonatal microglial characteristics. We therefore identify a unique phenotype of neonatal microglia that deliver signals necessary for myelination and neurogenesis