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1.
BMC Cell Biol ; 9: 26, 2008 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-18492269

RESUMO

BACKGROUND: Mammalian cells transform into individual tubular straw cells naturally in tissues and in response to desiccation related stress in vitro. The transformation event is characterized by a dramatic cellular deformation process which includes: condensation of certain cellular materials into a much smaller tubular structure, synthesis of a tubular wall and growth of filamentous extensions. This study continues the characterization of straw cells in blood, as well as the mechanisms of tubular transformation in response to stress; with specific emphasis placed on investigating whether tubular transformation shares the same signaling pathway as apoptosis. RESULTS: There are approximately 100 billion, unconventional, tubular straw cells in human blood at any given time. The straw blood cell count (SBC) is 45 million/ml, which accounts for 6.9% of the bloods dry weight. Straw cells originating from the lungs, liver and lymphocytes have varying nodules, hairiness and dimensions. Lipid profiling reveals severe disruption of the plasma membrane in CACO cells during transformation. The growth rates for the elongation of filaments and enlargement of rabbit straw cells is 0.6 approximately 1.1 (microm/hr) and 3.8 (microm(3)/hr), respectively. Studies using apoptosis inhibitors and a tubular transformation inhibitor in CACO2 cells and in mice suggested apoptosis produced apoptotic bodies are mediated differently than tubular transformation produced straw cells. A single dose of 0.01 mg/kg/day of p38 MAPK inhibitor in wild type mice results in a 30% reduction in the SBC. In 9 domestic animals SBC appears to correlate inversely with an animal's average lifespan (R2 = 0.7). CONCLUSION: Straw cells are observed residing in the mammalian blood with large quantities. Production of SBC appears to be constant for a given animal and may involve a stress-inducible protein kinase (P38 MAPK). Tubular transformation is a programmed cell survival process that diverges from apoptosis. SBCs may be an important indicator of intrinsic aging-related stress.


Assuntos
Apoptose , Células Sanguíneas/citologia , Células Sanguíneas/enzimologia , Estresse Fisiológico , Proteínas Quinases p38 Ativadas por Mitógeno/sangue , Envelhecimento , Clorometilcetonas de Aminoácidos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Contagem de Células Sanguíneas , Células Sanguíneas/efeitos dos fármacos , Caspase 3 , Bovinos , Transdiferenciação Celular/efeitos dos fármacos , Células Cultivadas , Citoesqueleto/enzimologia , Citoesqueleto/patologia , Desidratação/sangue , Desidratação/etiologia , Desidratação/patologia , Cães , Feminino , Cavalos , Humanos , Imidazóis/farmacologia , Sistema de Sinalização das MAP Quinases , Camundongos , Camundongos Endogâmicos BALB C , Miofibrilas , Piridinas/farmacologia , Quinolinas/farmacologia , Coelhos , Ratos , Ovinos , Especificidade da Espécie , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores
2.
BMC Cell Biol ; 8: 36, 2007 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-17705822

RESUMO

BACKGROUND: Tubular shaped mammalian cells in response to dehydration have not been previously reported. This may be due to the invisibility of these cells in aqueous solution, and because sugars and salts added to the cell culture for manipulation of the osmotic conditions inhibit transformation of normal cells into tubular shaped structures. RESULTS: We report the transformation of normal spherical mammalian cells into tubular shaped structures in response to stress. We have termed these transformed structures 'straw cells' which we have associated with a variety of human tissue types, including fresh, post mortem and frozen lung, liver, skin, and heart. We have also documented the presence of straw cells in bovine brain and prostate tissues of mice. The number of straw cells in heart, lung tissues, and collapsed straw cells in urine increases with the age of the mammal. Straw cells were also reproduced in vitro from human cancer cells (THP1, CACO2, and MCF7) and mouse stem cells (D1 and adipose D1) by dehydrating cultured cells. The tubular center of the straw cells is much smaller than the original cell; houses condensed organelles and have filamentous extensions that are covered with microscopic hair-like structures and circular openings. When rehydrated, the filaments uptake water rapidly. The straw cell walls, have a range of 120 nm to 200 nm and are composed of sulfated-glucose polymers and glycosylated acidic proteins. The transformation from normal cell to straw cells takes 5 to 8 hr in open-air. This process is characterized by an increase in metabolic activity. When rehydrated, the straw cells regain their normal spherical shape and begin to divide in 10 to 15 days. Like various types of microbial spores, straw cells are resistant to harsh environmental conditions such as UV-C radiation. CONCLUSION: Straw cells are specialized cellular structures and not artifacts from spontaneous polymerization, which are generated in response to stress conditions, like dehydration. The disintegrative, mobile, disruptive and ubiquitous nature of straw cells makes this a possible physiological process that may be involved in human health, longevity, and various types of diseases such as cancer.


Assuntos
Forma Celular , Estresse Fisiológico/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Carboidratos/análise , Bovinos , Sobrevivência Celular , Células Cultivadas , Criança , Pré-Escolar , Desidratação/patologia , Humanos , Camundongos , Pessoa de Meia-Idade , Modelos Biológicos , Espectroscopia de Infravermelho com Transformada de Fourier , Coloração e Rotulagem , Estresse Fisiológico/urina
3.
Genome Res ; 17(1): 7-15, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17151343

RESUMO

Soil bacteria that also form mutualistic symbioses in plants encounter two major levels of selection. One occurs during adaptation to and survival in soil, and the other occurs in concert with host plant speciation and adaptation. Actinobacteria from the genus Frankia are facultative symbionts that form N(2)-fixing root nodules on diverse and globally distributed angiosperms in the "actinorhizal" symbioses. Three closely related clades of Frankia sp. strains are recognized; members of each clade infect a subset of plants from among eight angiosperm families. We sequenced the genomes from three strains; their sizes varied from 5.43 Mbp for a narrow host range strain (Frankia sp. strain HFPCcI3) to 7.50 Mbp for a medium host range strain (Frankia alni strain ACN14a) to 9.04 Mbp for a broad host range strain (Frankia sp. strain EAN1pec.) This size divergence is the largest yet reported for such closely related soil bacteria (97.8%-98.9% identity of 16S rRNA genes). The extent of gene deletion, duplication, and acquisition is in concert with the biogeographic history of the symbioses and host plant speciation. Host plant isolation favored genome contraction, whereas host plant diversification favored genome expansion. The results support the idea that major genome expansions as well as reductions can occur in facultative symbiotic soil bacteria as they respond to new environments in the context of their symbioses.


Assuntos
Frankia/genética , Genoma Bacteriano , Magnoliopsida/microbiologia , Simbiose , Elementos de DNA Transponíveis , DNA Bacteriano , Evolução Molecular , Deleção de Genes , Duplicação Gênica , Geografia , Dados de Sequência Molecular , Fixação de Nitrogênio , Filogenia , Raízes de Plantas/microbiologia , Prófagos , Análise de Sequência de DNA
5.
Mol Genet Genomics ; 275(5): 479-91, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16501995

RESUMO

Fine mapping and positional cloning will eventually improve with the anchoring of additional markers derived from genomic clones such as BACs. From 2,603 new BAC-end genomic sequences from Gossypium hirsutum Acala 'Maxxa', 1,316 PCR primer pairs (designated as MUSB) were designed to flank microsatellite or simple sequence repeat motif sequences. Most (1164 or 88%) MUSB primer pairs successfully amplified DNA from three species of cotton with an average of three amplicons per marker and 365 markers (21%) were polymorphic between G. hirsutum and G. barbadense. An interspecific RIL population developed from the above two entries was used to map 433 marker loci and 46 linkage groups with a genetic distance of 2,126.3 cM covering approximately 45% of the cotton genome and an average distance between two loci of 4.9 cM. Based on genome-specific chromosomes identified in G. hirsutum tetraploid (A and D), 56.9% of the coverage was located on the A subgenome while 39.7% was assigned to the D subgenome in the genetic map, suggesting that the A subgenome may be more polymorphic and recombinationally active than originally thought. The linkage groups were assigned to 23 of the 26 chromosomes. This is the first genetic map in which the linkage groups A01 and A02/D03 have been assigned to specific chromosomes. In addition the MUSB-derived markers from BAC-end sequences markers allows fine genetic and QTL mapping of important traits and for the first time provides reconciliation of the genetic and physical maps. Limited QTL analyses suggested that loci on chromosomes 2, 3, 12, 15 and 18 may affect variation in fiber quality traits. The original BAC clones containing the newly mapped MUSB that tag the QTLs provide critical DNA regions for the discovery of gene sequences involved in biological processes such as fiber development and pest resistance in cotton.


Assuntos
Cromossomos Artificiais Bacterianos , Genoma de Planta , Gossypium/genética , Repetições de Microssatélites , Mapeamento Físico do Cromossomo , Marcadores Genéticos , Locos de Características Quantitativas
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