Identification and characterization of undifferentiated mast cells in mouse bone marrow

Blood ◽  
2005 ◽  
Vol 105 (11) ◽  
pp. 4282-4289 ◽  
Author(s):  
Maria Célia Jamur ◽  
Ana Cristina G. Grodzki ◽  
Elsa H. Berenstein ◽  
Majed M. Hamawy ◽  
Reuben P. Siraganian ◽  
...  

Abstract Sequential immunomagnetic isolation with 2 monoclonal antibodies was used to purify and characterize an undifferentiated mast cell in adult mouse bone marrow that had not been previously recognized. This cell represents 0.02% of the cells in the bone marrow, is CD34+, CD13+, and c-kit+, and does not express FcϵRI. However, by polymerase chain reaction (PCR) the cell contains message for the α and β subunits of FcϵRI, mast cell–specific proteases, and carboxypeptidase A. Morphologically, this cell has a large nucleus, little cytoplasm, few cytoplasmic organelles, and no cytoplasmic granules. In vitro, in the presence of interleukin-3 (IL-3) and stem cell factor (SCF) these cells differentiate only into a granulated mast cell that now expresses CD13, c-kit, mast cell–specific gangliosides, FcϵRI, and binds immunoglobulin E (IgE). When injected into lethally irradiated mice, these cells are able to reconstitute the mast cell population in the spleen.

Blood ◽  
1999 ◽  
Vol 93 (8) ◽  
pp. 2533-2542 ◽  
Author(s):  
Yuchen Gu ◽  
Lydia Sorokin ◽  
Madeleine Durbeej ◽  
Tord Hjalt ◽  
Jan-Ingvar Jönsson ◽  
...  

Abstract Laminins are extracellular matrix glycoproteins that influence the phenotype and functions of many types of cells. Laminins are heterotrimers composed of , β, and γ polypeptides. So far five , three β, and two γ polypeptide chains, and 11 variants of laminins have been proposed. Laminins interact in vitro with mature blood cells and malignant hematopoietic cells. Most studies have been performed with laminin-1 (1β1γ1), and its expression in bone marrow is unclear. Employing an antiserum reacting with most laminin isoforms, we found laminins widely expressed in mouse bone marrow. However, no laminin 1 chain but rather laminin 2, 4, and 5 polypeptides were found in bone marrow. Our data suggest presence of laminin-2 (2β1γ1), laminin-8 (4β1γ1), and laminin-10 (5β1γ1) in bone marrow. Northern blot analysis showed expression of laminin 1, 2, 4, and 5 chains in long-term bone marrow cultures, indicating upregulation of laminin 1 chain expression in vitro. Laminins containing 5 chain, in contrast to laminin-1, were strongly adhesive for multipotent hematopoietic FDCP-mix cells. Integrin 6 and β1 chains mediated this adhesion, as shown by antibody perturbation experiments. Our findings indicate that laminins other than laminin-1 are functional in adhesive interactions in bone marrow.


Blood ◽  
1999 ◽  
Vol 93 (8) ◽  
pp. 2533-2542 ◽  
Author(s):  
Yuchen Gu ◽  
Lydia Sorokin ◽  
Madeleine Durbeej ◽  
Tord Hjalt ◽  
Jan-Ingvar Jönsson ◽  
...  

Laminins are extracellular matrix glycoproteins that influence the phenotype and functions of many types of cells. Laminins are heterotrimers composed of , β, and γ polypeptides. So far five , three β, and two γ polypeptide chains, and 11 variants of laminins have been proposed. Laminins interact in vitro with mature blood cells and malignant hematopoietic cells. Most studies have been performed with laminin-1 (1β1γ1), and its expression in bone marrow is unclear. Employing an antiserum reacting with most laminin isoforms, we found laminins widely expressed in mouse bone marrow. However, no laminin 1 chain but rather laminin 2, 4, and 5 polypeptides were found in bone marrow. Our data suggest presence of laminin-2 (2β1γ1), laminin-8 (4β1γ1), and laminin-10 (5β1γ1) in bone marrow. Northern blot analysis showed expression of laminin 1, 2, 4, and 5 chains in long-term bone marrow cultures, indicating upregulation of laminin 1 chain expression in vitro. Laminins containing 5 chain, in contrast to laminin-1, were strongly adhesive for multipotent hematopoietic FDCP-mix cells. Integrin 6 and β1 chains mediated this adhesion, as shown by antibody perturbation experiments. Our findings indicate that laminins other than laminin-1 are functional in adhesive interactions in bone marrow.


Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 782
Author(s):  
Yin Shan Isa Mack ◽  
Masatoshi Dehari ◽  
Nobukatsu Morooka ◽  
Shinji Nagata

Arthropods, including insects, convert sterols into cholesterol due to the inability to synthesise cholesterol de novo. 24-dehydrocholesterol reductase (DHCR24) plays an important role in the conversion. Not only involving the cholesterol biosynthesis in vertebrates, DHCR24 is required for the conversion of desmosterol into cholesterol in phytophagous insects. The current study extensively examined DHCR24 in omnivorous insects, which feed on both plants and animals, using Gryllus bimaculatus as the experimental model. We identified cDNAs encoding two homologues of DHCR24 from G. bimaculatus, which were designated as GbDHCR24-1 and GbDHCR24-2. Both homologues contained the flavin adenine dinucleotide binding domain, which is a feature of DHCR24. Quantitative polymerase chain reaction revealed that among tissues of adult crickets, fat body and anterior midgut expressed high levels of GbDHCR24s. Both fat body and anterior midgut demonstrated DHCR24 activities in which one of the functions is the conversion of desmosterol into cholesterol in vitro. Knockdown of GbDHCR24-1 significantly reduced the conversion activity in the anterior midgut while knockdown of the GbDHCR24-2 did not. Additionally, the accumulation of desmosterol was detected in a feeding experiment with a specific DHCR24 inhibitor, azacosterol. We finally concluded that GbDHCR24-1 is the major enzyme that facilitates the desmosterol-to-cholesterol-conversion in crickets.


1992 ◽  
Vol 67 (01) ◽  
pp. 063-065 ◽  
Author(s):  
Sherryl A M Taylor ◽  
Jacalyn Duffin ◽  
Cherie Cameron ◽  
Jerome Teitel ◽  
Bernadette Garvey ◽  
...  

SummaryChristmas disease was first reported as a distinct clinical entity in two manuscripts published in 1952 (1, 2). The eponym associated with this disorder, is the surname of the first patient examined in detail and reported by Biggs and colleagues in a paper describing the clinical and laboratory features of seven affected individuals (3). This patient has severe factor IX coagulant deficiency (less than 0.01 units/ml) and no detectable circulating factor IX antigen (less than 0.01 units/ml). Coding sequence and splice junctions of the factor IX gene from this patient have been amplified in vitro through the polymerase chain reaction (PCR). One nucleotide substitution was identified at nucleotide 30,070 where a guanine was replaced by a cytosine. This mutation alters the amino acid encoded at position 206 in the factor IX protein from cysteine to serine. The non conservative nature of this substitution, the absence of this change in more than 200 previously sequenced factor IX genes and the fact that the remainder of the coding region of this gene was normal, all provide strong circumstantial evidence in favour of this change being the causative mutation in this patient. The molecular characterization of this novel mutation in the index case of Christmas disease, contributes to the rapidly expanding body of knowledge pertaining to Christmas disease pathogenesis.


2019 ◽  
Vol 19 (8) ◽  
pp. 633-644 ◽  
Author(s):  
Komal Kalani ◽  
Sarfaraz Alam ◽  
Vinita Chaturvedi ◽  
Shyam Singh ◽  
Feroz Khan ◽  
...  

Introduction: As a part of our drug discovery program for anti-tubercular agents, dihydroartemisinin (DHA-1) was screened against Mtb H37Rv, which showed moderate anti-tubercular activity (>25.0 µg/mL). These results prompted us to carry out the chemical transformation of DHA-1 into various derivatives and study their antitubercular potential. Materials and Methods: DHA-1 was semi-synthetically converted into four new acyl derivatives (DHA-1A – DHA-1D) and in-vitro evaluated for their anti-tubercular potential against Mycobacterium tuberculosis H37Rv virulent strain. The derivatives, DHA-1C (12-O-(4-nitro) benzoyl; MIC 12.5 µg/mL) and DHA-1D (12-O-chloro acetyl; MIC 3.12µg/mL) showed significant activity against the pathogen. Results: In silico studies of the most active derivative (DHA-1D) showed interaction with ARG448 inhibiting the mycobacterium enzymes. Additionally, it showed no cytotoxicity towards the Vero C1008 cells and Mouse bone marrow derived macrophages. Conclusion: DHA-1D killed 62% intracellular M. tuberculosis in Mouse bone marrow macrophage infection model. To the best of our knowledge, this is the first-ever report on the antitubercular potential of dihydroartemisinin and its derivatives. Since dihydroartemisinin is widely used as an antimalarial drug; these results may be of great help in anti-tubercular drug development from a very common, inexpensive, and non-toxic natural product.


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