26 research outputs found
Bmp7 Functions via a Polarity Mechanism to Promote Cloacal Septation
During normal development in human and other placental mammals, the embryonic cloacal cavity separates along the axial longitudinal plane to give rise to the urethral system, ventrally, and the rectum, dorsally. Defects in cloacal development are very common and present clinically as a rectourethral fistula in about 1 in 5,000 live human births. Yet, the cellular mechanisms of cloacal septation remain poorly understood.We previously detected Bone morphogenetic protein 7 (Bmp7) expression in the urorectal mesenchyme (URM), and have shown that loss of Bmp7 function results in the arrest of cloacal septation. Here, we present evidence that cloacal partitioning is driven by Bmp7 signaling in the cloacal endoderm. We performed TUNEL and immunofluorescent analysis on cloacal sections from Bmp7 null and control littermate embryos. We found that loss of Bmp7 results in a dramatic decrease in the endoderm survival and a delay in differentiation. We used immunological methods to show that Bmp7 functions by activating the c-Jun N-terminal kinase (JNK) pathway. We carried out confocal and 3D imaging analysis of mitotic chromosome bundles to show that during normal septation cells in the cloacal endoderm divide predominantly in the apical-basal direction. Loss of Bmp7/JNK signaling results in randomization of mitotic angles in the cloacal endoderm. We also conducted immunohistochemical analysis of human fetal sections to show that BMP/phospho-SMAD and JNK pathways function in the human cloacal region similar as in the mouse.Our results strongly indicate that Bmp7/JNK signaling regulates remodeling of the cloacal endoderm resulting in a topological separation of the urinary and digestive systems. Our study points to the importance of Bmp and JNK signaling in cloacal development and rectourethral malformations
Cryoconite – from minerals and organic matter to bioengineeredsediments on glacier's surfaces
Cryoconite is a mixture of mineral and organic material covering glacial ice, playing important roles in biogeochemical
cycles and lowering the albedo of a glacier surface. Understanding the differences in structure of
cryoconite across the globe can be important in recognizing past and future changes in supraglacial environments
and ice-organisms-minerals interactions. Despite the worldwide distribution and over a century of studies, the
basic characteristics of cryoconite, including its forms and geochemistry, remain poorly studied. The major purpose
of our study is the presentation and description of morphological diversity, chemical and photoautotrophs
composition, and organic matter content of cryoconite sampled from 33 polar and mountain glaciers around the
globe. Observations revealed that cryoconite is represented by various morphologies including loose and granular
forms. Granular cryoconite includes smooth, rounded, or irregularly shaped forms; with some having their
surfaces covered by cyanobacteria filaments. The occurrence of granules increased with the organic matter content
in cryoconite.Moreover, amajor driver of cryoconite colouringwas the concentration of organicmatter and
its interplay with minerals. The structure of cyanobacteria and algae communities in cryoconite differs between
glaciers, but representatives of cyanobacteria families Pseudanabaenaceae and Phormidiaceae, and algae families
Mesotaeniaceae and Ulotrichaceaewere themost common. Themost of detected cyanobacterial taxa are known
to produce polymeric substances (EPS) that may cement granules. Organic matter content in cryoconite varied
between glaciers, ranging from 1% to 38%. The geochemistry of all the investigated samples reflected local sediment
sources, except of highly concentrated Pb andHg in cryoconite collected fromEuropean glaciers near industrialized
regions, corroborating cryoconite as element-specific collector and potential environmental indicator of
anthropogenic activity. Our work supports a notion that cryoconite may bemore than just simple sediment and
instead exhibits complex structure with relevance for biodiversity and the functioning of glacial ecosystem
In vitro and in vivo neuroprotective effects of cJun N-terminal kinase inhibitors on retinal ganglion cells
Importance of nest boxes for breeding birds in forest areas - the Wielkopolski National Park case study
The study embraced 159 nest boxes placed in three different study plots in the Wielkopolski National Park in western Poland. In the first season, 64% of nest boxes were occupied by four species: great tit Parus major, blue tit Cyanistes caeruleus, Eurasian nuthatch Sitta europaea and European pied flycatcher Ficedula hypoleuca. The dominant species were great and blue tits. Over 80% of broods of great tits and blue tits were reared successfully. Birds preferred nest boxes located in plots with domination of oaks and Scots pine and with rich underbrush. Woodpeckers damaged entrances of 70% of the nest boxes, but did not cause any brood losses. In 13% of the boxes nests of hornets, bumblebees and wasps were found. Bumblebees chose boxes with a bird nest material, whereas wasps and hornets avoided sites occupied by the birds. In general, the insects had a small impact on breeding success of birds and caused failure of only 3% of all broods. Obtained results show that nest boxes in forests may increase density of the most common cavity nesters and secure their high breeding success
Zastosowanie biosurfaktantów do wytwarzania nowoczesnych żeli pod prysznic o podwyższonym bezpieczeństwie stosowania
In the paper the influence of the type of surfactant in shaping safety of shower gels was presented. For this purpose, two types of washing cosmetics different in terms of surface active compound were used. In regard of increasing environmental awareness of consumers and on the basis of „green chemistry”, a mild surfactant – Inulin Lauryl Carbamate (lNCI) has been used in the former preparation. The ingredient in the second washing cosmetics was Sodium Laureth Sulfate (SLES) – a widely used anion surfactant. The irritation potential on the basis of the zein value as well as the skin dryness level were assessed in these preparations.W pracy przedstawiono wpływ rodzaju surfaktantu na kształtowanie bezpieczeństwa stosowania żeli pod prysznic. W tym celu opracowano dwa prototypy kosmetyków myjących, różniących się zastosowanym związkiem powierzchniowo czynnym. W związku ze stale wzrastającą świadomością środowiskową konsumentów oraz na podstawie zasad „zielonej chemii” w pierwszym z preparatów zastosowano delikatny biosurfaktant – Inulin Lauryl Carbamate (laurylokarbaminian inuliny). W składzie drugiego prototypu kosmetyku myjącego znalazł się powszechnie stosowany anionowy surfaktant – oksyetylenowany laurylosiarczan sodu (SLES). Dla preparatów dokonano oceny potencjału drażniącego na podstawie liczby zeinowej oraz stopnia wysuszenia skóry
Crystal and Solution Structure Analysis of FhuD2 from <i>Staphylococcus aureus</i> in Multiple Unliganded Conformations and Bound to Ferrioxamine‑B
Iron acquisition is a central process
for virtually all organisms.
In <i>Staphylococcus aureus</i>, FhuD2 is a lipoprotein
that is a high-affinity receptor for iron-bound hydroxamate siderophores.
In this study, FhuD2 was crystallized bound to ferrioxamine-B (FXB),
and also in its ligand-free state; the latter structures are the first
for hydroxamate-binding receptors within this protein family. The
structure of the FhuD2–FXB conformation shows that residues
W197 and R199 from the C-terminal domain donate hydrogen bonds to
the hydroxamate oxygens, and a ring of aromatic residues cradles the
aliphatic arms connecting the hydroxamate moieties of the siderophore.
The available ligand-bound structures of FhuD from <i>Escherichia
coli</i> and YfiY from <i>Bacillus cereus</i> show
that, despite a high degree of structural conservation, three protein
families have evolved with critical siderophore binding residues on
either the C-terminal domain (<i>S. aureus</i>), the N-terminal
domain (<i>E. coli</i>), or both (<i>B. cereus</i>). Unliganded FhuD2 was crystallized in five conformations related
by rigid body movements of the N- and C-terminal domains. Small-angle
X-ray scattering (SAXS) indicates that the solution conformation of
unliganded FhuD2 is more compact than the conformations observed in
crystals. The ligand-induced conformational changes for FhuD2 in solution
are relatively modest and depend on the identity of the siderophore.
The crystallographic and SAXS results are used to discuss roles for
the liganded and unliganded forms of FhuD2 in the siderophore transport
mechanism