Studies on aecial development in rust fungi: Puccinia polliniae

1969 ◽  
Vol 47 (5) ◽  
pp. 741-744 ◽  
Author(s):  
B. V. Singh
Keyword(s):  
Basal Cell ◽  
Rust Fungi ◽  
Western Himalayas ◽  
Basal Cells ◽  
Pale Yellow ◽  
Transverse Division ◽  
Peridial Cell ◽  
Intercalary Cell ◽  
Mother Cells ◽  
Dual Origin

The leaves of Goldfussia dalhousiana become infected by Puccinia polliniae with the onset of rains in the Western Himalayas. Pale yellow dots appear on the leaves, developing into pustules and extending centrifugally. Pycnia develop on the upper surface and aecia on the lower. Protoaecia are differentiated into fertile and displacement zones. After dikaryotization, the basal cells elongate, become binucleate, and, by transverse conjugate division, produce the aeciospore mother cells. By transverse division, each of these form a large aeciospore and a small disjunctor cell towards the basal cell. The basal cells at the periphery, by transverse conjugate divisions, give peridial mother cells each of which by an oblique conjugate division cuts off an intercalary cell towards the outside and a peridial cell towards the inside. The peridial cells develop thick walls and the intercalary cells degenerate. The peridium has a dual origin and the aecia are of the aecidioid type. The aeciospores are circular to oval in shape, binucleate, and multiguttulate. They have radially striate thickened walls and two to three germ pores.

scholarly journals Extracellular vesicles from human airway basal cells respond to cigarette smoke extract and affect vascular endothelial cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ashish Saxena ◽  
Matthew S. Walters ◽  
Jae-Hung Shieh ◽  
Ling-Bo Shen ◽  
Kazunori Gomi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cigarette Smoke ◽  
Extracellular Vesicles ◽  
Basal Cell ◽  
Mapk Signaling ◽  
Cigarette Smoke Extract ◽  
Vegf Receptor ◽  
Vascular Endothelial ◽  
Basal Cells ◽  
Human Airway

AbstractThe human airway epithelium lining the bronchial tree contains basal cells that proliferate, differentiate, and communicate with other components of their microenvironment. One method that cells use for intercellular communication involves the secretion of exosomes and other extracellular vesicles (EVs). We isolated exosome-enriched EVs that were produced from an immortalized human airway basal cell line (BCi-NS1.1) and found that their secretion is increased by exposure to cigarette smoke extract, suggesting that this stress stimulates release of EVs which could affect signaling to other cells. We have previously shown that primary human airway basal cells secrete vascular endothelial growth factor A (VEGFA) which can activate MAPK signaling cascades in endothelial cells via VEGF receptor–2 (VEGFR2). Here, we show that exposure of endothelial cells to exosome-enriched airway basal cell EVs promotes the survival of these cells and that this effect also involves VEGFR2 activation and is, at least in part, mediated by VEGFA present in the EVs. These observations demonstrate that EVs are involved in the intercellular signaling between airway basal cells and the endothelium which we previously reported. The downstream signaling pathways involved may be distinct and specific to the EVs, however, as increased phosphorylation of Akt, STAT3, p44/42 MAPK, and p38 MAPK was not seen following exposure of endothelial cells to airway basal cell EVs.

Another role for melanocytes: their importance for normal stria vascularis development in the mammalian inner ear

Development ◽  
1989 ◽  
Vol 107 (3) ◽  
pp. 453-463 ◽  
Author(s):  
K.P. Steel ◽  
C. Barkway
Keyword(s):  
Neural Crest ◽  
Basal Cell ◽  
Stria Vascularis ◽  
Normal Adult ◽  
Basal Cells ◽  
Cochlear Duct ◽  
Cell Layers ◽  
Marginal Cells ◽  
Intermediate Cells ◽  
And Function

The stria vascularis of the mammalian cochlea is composed primarily of three types of cells. Marginal cells line the lumen of the cochlear duct and are of epithelial origin. Basal cells also form a continuous layer and they may be mesodermal or derived from the neural crest. Intermediate cells are melanocyte-like cells, presumably derived from the neural crest, and are scattered between the marginal and basal cell layers. The marginal cells form extensive interdigitations with the basal and intermediate cells in the normal adult stria. The stria also contains a rich supply of blood vessels. We investigated the role of melanocytes in the stria vascularis by studying its development in a mouse mutant, viable dominant spotting, which is known to have a primary neural crest defect leading to an absence of recognisable melanocytes in the skin. Melanocytes were not found in the stria of most of the mutants examined, and from about 6 days of age onwards a reduced amount of interdigitation amongst the cells of the stria was observed. These ultrastructural anomalies were associated with strial dysfunction. In the normal adult mammal, the stria produces an endocochlear potential (EP), a resting dc potential in the endolymph in the cochlear duct, which in mice is normally about +100 mV. In our control mice, EP rose to adult levels between 6 and 16 days after birth. In most of the mutants we studied, EP was close to zero at all ages from 6 to 20 days. Melanocyte-like cells appear to be vital for normal stria vascularis development and function. They may be necessary to facilitate the normal process of interdigitation between marginal and basal cell processes at a particular stage during development, and the lack of adequate interdigitation in the mutants may be the cause of their strial dysfunction. Alternatively, melanocytes may have some direct, essential role in the production of an EP by the stria. Melanocytes may be important both for normal strial development and for the production of the EP. We believe this is the clearest demonstration yet of a role for migratory melanocytes other than their role in pigmentation.

scholarly journals Progenitor identification and SARS-CoV-2 infection in long-term human distal lung organoid cultures

2020 ◽  
Author(s):  
Ameen A. Salahudeen ◽  
Shannon S. Choi ◽  
Arjun Rustagi ◽  
Junjie Zhu ◽  
Sean M. de la O ◽  
...  
Keyword(s):  
Lung Disease ◽  
Single Cell ◽  
Basal Cell ◽  
Human Lung ◽  
Basal Cells ◽  
Ciliated Cells ◽  
Club Cells ◽  
Distal Lung

ABSTRACTThe distal lung contains terminal bronchioles and alveoli that facilitate gas exchange and is affected by disorders including interstitial lung disease, cancer, and SARS-CoV-2-associated COVID-19 pneumonia. Investigations of these localized pathologies have been hindered by a lack of 3D in vitro human distal lung culture systems. Further, human distal lung stem cell identification has been impaired by quiescence, anatomic divergence from mouse and lack of lineage tracing and clonogenic culture. Here, we developed robust feeder-free, chemically-defined culture of distal human lung progenitors as organoids derived clonally from single adult human alveolar epithelial type II (AT2) or KRT5+ basal cells. AT2 organoids exhibited AT1 transdifferentiation potential, while basal cell organoids progressively developed lumens lined by differentiated club and ciliated cells. Organoids consisting solely of club cells were not observed. Upon single cell RNA-sequencing (scRNA-seq), alveolar organoids were composed of proliferative AT2 cells; however, basal organoid KRT5+ cells contained a distinct ITGA6+ITGB4+ mitotic population whose proliferation segregated to a TNFRSF12Ahi subfraction. Clonogenic organoid growth was markedly enriched within the TNFRSF12Ahi subset of FACS-purified ITGA6+ITGB4+ basal cells from human lung or derivative organoids. In vivo, TNFRSF12A+ cells comprised ~10% of KRT5+ basal cells and resided in clusters within terminal bronchioles. To model COVID-19 distal lung disease, we everted the polarity of basal and alveolar organoids to rapidly relocate differentiated club and ciliated cells from the organoid lumen to the exterior surface, thus displaying the SARS-CoV-2 receptor ACE2 on the outwardly-facing apical aspect. Accordingly, basal and AT2 “apical-out” organoids were infected by SARS-CoV-2, identifying club cells as a novel target population. This long-term, feeder-free organoid culture of human distal lung alveolar and basal stem cells, coupled with single cell analysis, identifies unsuspected basal cell functional heterogeneity and exemplifies progenitor identification within a slowly proliferating human tissue. Further, our studies establish a facile in vitro organoid model for human distal lung infectious diseases including COVID-19-associated pneumonia.

scholarly journals Basal stem cell fate specification is mediated by SMAD signaling in the developing human lung

2018 ◽  
Author(s):  
Alyssa J. Miller ◽  
Qianhui Yu ◽  
Michael Czerwinski ◽  
Yu-Hwai Tsai ◽  
Renee F. Conway ◽  
...  
Keyword(s):  
Single Cell ◽  
Progenitor Cells ◽  
Cell Fate ◽  
Basal Cell ◽  
Human Lung ◽  
Branching Morphogenesis ◽  
Basal Cells ◽  
Smad Signaling ◽  
Cell Fate Decisions ◽  
Cell Transition

AbstractBasal stem cells (basal cells), located in the bronchi and trachea of the human lung epithelium, play a critical role in normal airway homeostasis and repair, and have been implicated in the development of diseases such as cancer1-4. Additionally, basal-like cells contribute to alveolar regeneration and fibrosis following severe injury5-8. However, the developmental origin of basal cells in humans is unclear. Previous work has shown that specialized progenitor cells exist at the tips of epithelial tubes during lung branching morphogenesis, and in mice, give rise to all alveolar and airway lineages9,10. These ‘bud tip progenitor cells’ have also been described in the developing human lung11-13, but the mechanisms controlling bud tip differentiation into specific cell lineages, including basal cells, are unknown. Here, we interrogated the bud tip-to-basal cell transition using human tissue specimens, bud tip progenitor organoid cultures11, and single-cell transcriptomics. We used single-cell mRNA sequencing (scRNAseq) of developing human lung specimens from 15-21 weeks gestation to identify molecular signatures and cell states in the developing human airway epithelium. We then inferred differentiation trajectories during bud tip-to-airway differentiation, which revealed a previously undescribed transitional cell state (‘hub progenitors’) and implicated SMAD signaling as a regulator of the bud tip-to-basal cell transition. We used bud tip progenitor organoids to show that TGFT1 and BMP4 mediated SMAD signaling robustly induced the transition into functional basal-like cells, and these in vitro-derived basal cells exhibited clonal expansion, self-renewal and multilineage differentiation. This work provides a framework for deducing and validating key regulators of cell fate decisions using single cell transcriptomics and human organoid models. Further, the identification of SMAD signaling as a critical regulator of newly born basal cells in the lung may have implications for regenerative medicine, basal cell development in other organs, and understanding basal cell misregulation in disease.

scholarly journals Airway tissue stem cells reutilize the embryonic proliferation regulator, Tgfß-Id2 axis, for tissue regeneration

2020 ◽  
Author(s):  
Hirofumi Kiyokawa ◽  
Akira Yamaoka ◽  
Chisa Matsuoka ◽  
Tomoko Tokuhara ◽  
Takaya Abe ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Tissue Regeneration ◽  
Basal Cell ◽  
Molecular Mechanisms ◽  
Fine Tuning ◽  
Basal Cells ◽  
Adult Tissue ◽  
Epithelial Regeneration ◽  
Slow Cycling

SummaryDuring development, quiescent basal stem cells are derived from proliferative primordial progenitors through the cell cycle slowdown. In contrast, quiescent basal cells contribute to tissue repair during adult tissue regeneration by shifting from slow-cycling to proliferating and subsequently back to slow-cycling. Although sustained basal cell proliferation results in tumorigenesis, the molecular mechanisms regulating these transitions remain unknown. Using temporal single-cell transcriptomics of developing murine airway progenitors and in vivo genetic validation experiments, we found that Tgfß signaling slowed down cell cycle by inhibiting Id2 expression in airway progenitors and contributed to the specification of slow-cycling basal cell population during development. In adult tissue regeneration, reduced Tgfß signaling restored Id2 expression and initiated epithelial regeneration. Id2 overexpression and Tgfbr2 knockout enhanced epithelial proliferation; however, persistent Id2 expression in basal cells drove hyperplasia at a rate that resembled a precancerous state. Together, the Tgfß-Id2 axis commonly regulates the proliferation transitions in airway basal cells during development and regeneration, and its fine-tuning is critical for normal regeneration while avoiding basal cell hyperplasia.

scholarly journals Discovery and 3D imaging of a novel ΔNp63-expressing basal cell type in human pancreatic ducts with implications in disease

2020 ◽  
Author(s):  
Sandrina Martens ◽  
Mathias Van Bulck ◽  
Katarina Coolens ◽  
Hediel Madhloum ◽  
Farzad Esni ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Stem Cell ◽  
Chronic Pancreatitis ◽  
Basal Cell ◽  
3D Imaging ◽  
Stem Cell Markers ◽  
List Type ◽  
Human Pancreas ◽  
Basal Cells ◽  
Cell Markers

SUMMARYObjectiveAn aggressive basal-like molecular subtype of pancreatic ductal adenocarcinoma (PDAC) exists, driven by ΔNp63. In other epithelia, ΔNp63+ basal cells have stem cell capacity and can be at the origin of tumors. In the pancreas, basal cells have not been identified.DesignWe assessed basal cell markers in human and mouse pancreas, chronic pancreatitis and PDAC, and developed a 3D imaging protocol (FLIP-IT) to study sizeable samples at single cell resolution. We generated organoid cultures of ducts from Sox9-eGFP reporter mice.ResultsIn normal human pancreas, rare ΔNp63+ cells exist in ducts that expand in chronic pancreatitis. ΔNp63+ cells express KRT19 and canonical basal markers (KRT5, KRT14 and S100A2) but lack markers of duct cells such as CA19.9 and SOX9. In addition, ΔNp63+ cells pertain to a niche of cells expressing gastrointestinal stem cell markers. 3D views of the ductal tree in formalin fixed paraffin embedded samples show that basal cells are localized on the basal membrane of medium to large ducts and expand as multilayer dome-like structures in chronic pancreatitis. In mice, ΔNp63 expression is induced when culturing organoids from Sox9-low ductal cells but could not be found in normal pancreas nor in models of pancreatitis or pancreatic cancer.ConclusionWe discovered a novel ductal cell population in normal human pancreas similar to basal cells in other tissues. Using FLIP-IT, we provide unprecedented 3D visualization of these cells in archival clinical specimens. ΔNp63+ cells may play an important role in pancreatic tissue regeneration and cancer.SUMMARY BOXWhat is already known about this subject?ΔNp63 has a central role in determining the basal-like subtype of pancreatic ductal adenocarcinoma (PDAC).Different to other tissues with basal cancers, the normal pancreas reportedly does not contain (ΔNp63-expressing) basal cells.Current protocols face severe limitations for marker-based identification and 3D imaging of individual (rare) cells in archival pancreatic samples.What are the new findings?We report a rare and atypical pancreatic duct cell that expresses ΔNp63, other basal cell markers and g.i. stem cell markers.The number of these basal cells increases in diseases such as chronic pancreatitis and pancreatic cancer.We provide an easy to implement protocol for 3D clearing and high-resolution imaging of sizeable samples of (fresh or FFPE) human pancreas or an entire mouse pancreas.Except after culturing medium to large ducts as organoids, we fail to detect basal cells in mouse experimental pancreatic models.How might it impact on clinical practice in the foreseeable future?Extrapolating from knowledge in other organs, basal cells in the pancreas may have a stem cell/progenitor role, including in diseases such as (basal) pancreatic cancer.Use of the 3D imaging protocol in archival clinical specimens will allow unprecedented insights in pancreatic histopathology.For above mentioned diseases, we caution for findings in experimental mouse models that may not (fully) recapitulate the etiopathogenesis.

Ultrastructural Characteristics of Capillaries Entering and Leaving the Stria Vascularis

1986 ◽  
Vol 95 (3) ◽  
pp. 309-312 ◽  
Author(s):  
Kensuke Watanabe
Keyword(s):  
Horseradish Peroxidase ◽  
Basal Cell ◽  
Stria Vascularis ◽  
The Other ◽  
Spiral Ligament ◽  
Perivascular Spaces ◽  
Basal Cells ◽  
Vascular Flow ◽  
Cell Layers ◽  
Ultrastructural Characteristics

Capillaries entering and leaving the stria vascularis were surrounded by layers of basal cells and fibrocytes. The entering capillaries were surrounded by one or two thin basal cells, while the leaving capillaries were surrounded by four or five thicker and interdigitated basal cell layers. Moreover, the layers surrounding the leaving capillaries persisted further into the spiral ligament. Two kinds of filaments were observed in the basal cells, one thin and the other thick. Capillaries were observed to leak horseradish peroxidase before they entered and after they left the stria vascularis. Although the reaction product of horseradish peroxidase was observed in all perivascular spaces of leaving capillaries, very little or no reaction product was observed around some entering capillaries. It is speculated that the layers of basal cells and fibrocytes around entering and leaving capillaries control the vascular flow out of the stria vascularis, although the layers around leaving capillaries may be more contractile than those around entering capillaries.

scholarly journals Use of Cytology in the Diagnosis of Basal Cell Carcinoma Subtypes

2020 ◽  
Vol 9 (3) ◽  
pp. 612
Author(s):  
Paola Pasquali ◽  
Gonzalo Segurado-Miravalles ◽  
Mar Castillo ◽  
Ángeles Fortuño ◽  
Susana Puig ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Basal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Basal Cell ◽  
Inverse Correlation ◽  
Basal Cells ◽  
White Population ◽  
First Line ◽  
Common Skin ◽  
Cytological Features

Background: Basal cell carcinoma (BCC) is the most common skin cancer in the white population. Nonsurgical treatments are first-line alternatives in superficial BCC (sBCC); therefore, differentiating between sBCC and non-sBCC is of major relevance for the clinician. Scraping cytology possesses several advantages, such as an earlier diagnosis and scarring absence, in comparison to a biopsy. Nevertheless, previous studies reported difficulties in differentiating the different BCC subtypes. The objective of this study was to determine the capability and accuracy of scraping cytology to differentiate between sBCC and non-sBCC. Methods: In this retrospective study, cytological samples of histologically confirmed BCC were examined. Select cytological features were correlated to BCC subtypes (sBCC or non-sBCC). Results: A total of 84 BCC samples were included (29 sBCC; 55 non-sBCC). An inverse correlation between the diagnosis of sBCC and the presence of mucin, dehiscence, and grade of atypia in the basal cells was observed. The presence of medium and large basal cell clusters correlated directly to a sBCC diagnosis. The presence of clear cells is strongly associated with sBCC. Therefore, Conclusion: Scraping cytology is reliable in differentiating sBCC from other BCC subtypes.

scholarly journals Submikroskopische Untersuchungen am Basaliom des Hundes

1968 ◽  
Vol 5 (2) ◽  
pp. 174-185
Author(s):  
W. Drommer
Keyword(s):  
Basal Cell ◽  
Single Cells ◽  
Cell Tumor ◽  
Basal Cells ◽  
Sebaceous Glands ◽  
Intercellular Spaces ◽  
Different Types

Six basal cell tumors of dogs were studied electron microscopically. The ultrastructure of different types of basal cell tumor differs as to the number of tonofibrils, the finger-like cytoplasmic extensions, the width of the intercellular spaces, and the hyaloplasma. Hemidesmosomes were found in all tumors. One basal cell tumor contained single cells resembling sebaceous cells which indicates differentiation of basal cells into sebaceous glands. Furthermore, there are ultrastructural differences between the cells of the stratum germinativum and the basal cell tumor.

Ramakrishnania, a new genus of Uredinales from southern India

1979 ◽  
Vol 57 (7) ◽  
pp. 783-786
Author(s):  
P. Ramachar ◽  
G. Bhagyanarayana
Keyword(s):  
Basal Cell ◽  
Type Species ◽  
New Genus ◽  
Rust Fungi ◽  
Southern India ◽  
Indeterminate Growth ◽  
Distinct Features

Ramakrishnania is described as a new genus of rust fungi with R. ixorae n.sp as the type species. Distinct features of this genus are the indeterminate growth of the basal cell and the formation of two-celled puccinioid teliospores on septate simple pedicels bilaterally on the elongating basal cell.

Sign in / Sign up

Export Citation Format

Share Document