A TRP to cardiac fibroblast differentiation.
Female; Humans; Male; Animals; TRPV4; *Wound Healing; TRPV Cation Channels/*metabolism; integrin; *Cell Differentiation; cardiac fibroblast; myofibroblast; *Calcium Signaling; *Cell Transdifferentiation; Atrial Fibrillation/*metabolism; differentiation; ECM stiffness; Fibroblasts/*metabolism/*physiology; mechanical signaling; Myofibroblasts/*cytology/*metabolism; Rho/ROCK; TRPC Cation Channels/*metabolism; TRPM Cation Channels/*metabolism; Cellular; *Mechanotransduction
The differentiation of cardiac fibroblasts to myofibroblasts is one of the key events during cardiac remodeling, however, the molecular mechanism underlying this process is not well known. Calcium signaling plays an important role in the regulation of cardiac fibroblast function, but its role in the differentiation of fibroblasts is undefined. Recently four Transient Receptor Potential (TRP) channels TRPM7, TRPC3, TRPC6 and TRPV4 were shown to be crucial for the differentiation of cardiac fibroblasts to myofibroblasts. This addendum sums up the roles described for these four TRP channels in cardiac fibroblast differentiation, and discusses the possible molecular mechanisms underlying this process and its relevance for cardiac remodeling in disease.
Thodeti Charles K; Paruchuri Sailaja; Meszaros J Gary
Channels (Austin, Tex.)
2013
2013-06
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.4161/chan.24328" target="_blank" rel="noreferrer noopener">10.4161/chan.24328</a>
Syringocystadenoma papilliferum of the male breast
apocrine; Breast; Dermatology; differentiation; eccrine differentiation; GCDFP-15; lysozyme; male; plasma cell infiltrate; syringocystadenoma papilliferum; tumors
A 39-year-old man presented with a 2-cm, mildly tender mass in the right breast of many years' duration. Microscopic examination showed a syringocystadenoma papilliferum. Because of its location in the breast, we studied the lesion for immunohistochemical markers for apocrine differentiation. Gross cystic disease fluid protein-15 (GCDFP-15) staining yielded negative results in the cystic luminal epithelial cells, whereas GCDFP-15 and lysozyme staining yielded strongly positive results in the epithelial cells of adjacent tubular apocrine glands. Focal strong lysozyme positivity was seen in the cystic luminal epithelial cells. These findings do not support apocrine differentiation in this case, despite its location in the breast, an organ rich in specialized apocrine (lactiferous) elands. To our knowledge, this represents the first reported case of syringocystadenoma papilliferum of the male breast. We present the clinical and pathologic features of this unusual case and a review of the literature.
Nowak M; Pathan A; Fatteh S; Lopez J
American Journal of Dermatopathology
1998
1998-08
Journal Article
<a href="http://doi.org/10.1097/00000372-199808000-00019" target="_blank" rel="noreferrer noopener">10.1097/00000372-199808000-00019</a>
Cross-Talk Between Stem Cells and the Dysfunctional Brain is Facilitated by Manipulating the Niche: Evidence from an Adhesion Molecule
adhesion molecule; Aging; aging and age-related diseases; astrocytes; axonal regeneration; Biotechnology & Applied Microbiology; Cell Biology; central-nervous-system; chaperone effect; differentiation; dopamine; extracellular; functional recovery; Hematology; L1; matrix; migration; model; molecules; motor-neurons; mouse; MPTP; neural stem cells; neurodegeneration; neuroprotection; neurotrophic factors; niche; Oncology; oxidative stress; parkinsons-disease; parkinsons-disease; protect neurons; recognition; spinal-cord-injury; transplantation
In the injured brain, the behavior of neural stem/progenitor cells (NSCs) is regulated by multiple converging factors encountered in the niche, which is composed of several neural and non-neural cell types. Signals emanating from the host influence the migration, survival, distribution, and fate of transplanted NSCs, which in turn can create host microenvironments that favor a return to homeostasis. We tested the hypothesis that overexpression of key facilitatory molecules that de. ne the injury niche might enhance this bidirectional stem cell host interaction to therapeutic advantage. As proof of concept, we investigated whether conditioning the niche with the neural cell adhesion molecule L1 might enhance recovery in a prototypical neurodegenerative milieu-the MPTP-induced model of Parkinson's disease in aged mice-where cross-talk between NSCs and imperiled host dopaminergic neurons is known to be pivotal in rescuing the function and connectivity of the latter. In lesioned mice (and in unlesioned controls), we overexpressed L1 in the NSCs to be transplanted into the ventral mesencephalon. Several pairwise experimental combinations were tested based on variations of engrafting L1 overexpressing versus nonoverexpressing NSCs into wild-type (WT) versus L1-overexpressing transgenic mice (specifically L1 transcribed from the GFAP promoter and, hence, overexpressed in host astrocytes). Enrichment for L1-particularly when expressed simultaneously in both donor NSCs and host brain-led to rapid and extensive distribution of exogenous NSCs, which in turn rescued (with an efficacy greater than in nonengineered controls) dysfunctional host dopaminergic nigral neurons, even when grafting was delayed by a month. L1 overexpression by NSCs also enhanced their own differentiation into tyrosine hydroxylase-expressing neurons in both WT and transgenic hosts. Graft-host interactions were thus favored by progressively increasing levels of L1. More broadly, this study supports the view that manipulating components of the niche (such as an adhesion molecule) that facilitate cross-talk between stem cells and the dysfunctional brain may offer new strategies for more efficacious neurotransplantation, particularly when treatment is delayed as in chronic lesions or advanced stages of a neurodegenerative disease. STEM CELLS 2009; 27: 2846-2856
Ourednik V; Ourednik J; Xu Y F; Zhang Y; Lynch W P; Snyder E Y; Schachner M
Stem Cells
2009
2009-11
Journal Article
<a href="http://doi.org/10.1002/stem.227" target="_blank" rel="noreferrer noopener">10.1002/stem.227</a>
A Novel Hybrid-Structured Titanium Surface Promotes Adhesion of Human Dermal Fibroblasts and Osteogenesis of Human Mesenchymal Stem Cells while Reducing S-epidermidis Biofilm Accumulation
differentiation; energy; hydrophilicity; implants; in-vitro; Materials Science; nanotopography; osseointegration; osteoactivin; osteoblast lineage cells; responses
We provide a comparative analysis of protein adsorption, primary human cell behavior, and biofilm formation on modified titanium substrates of either micro-, nano-, or hybrid micro/nano-scale feature sizes. While studies revealed that nano-scale structures initially decreased the attachment and spreading of both human fibroblasts (hDFs) and mesenchymal stem cells (hMSCs), hMSC differentiation studies revealed that hybrid structures promoted the highest levels of osteogenic gene expression and attenuated biofilm formation by Staphylococcus epidermidis. Taken together, this novel approach of generating a hybrid topographical feature results in a potential implant material capable of enhanced dermal cell adhesion and osteogenic differentiation while limiting biofilm accumulation.
Park B W; Krieger J; Sondag G R; Moussa F M; Rankenberg J; Safadi F F; Gatsonis N A; McGimpsey W G; Lambert C R; Malcuit C
Advanced Engineering Materials
2016
2016-04
Journal Article
<a href="http://doi.org/10.1002/adem.201500282" target="_blank" rel="noreferrer noopener">10.1002/adem.201500282</a>
Morphoregulation of teeth: modulating the number, size, shape and differentiation by tuning Bmp activity
ameloblast; Bone morphogenetic protein-2; dentition; Developmental Biology; differentiation; early tooth development; enamel knot; Evolutionary Biology; Genetics & Heredity; homeobox genes; in-vitro; missense mutation; molar teeth; murine; signaling pathways
During development and evolution, the morphology of ectodermal organs can be modulated so that an organism can adapt to different environments. We have proposed that morphoregulation can be achieved by simply tilting the balance of molecular activity. We test the principles by analyzing the effects of partial downregulation of Bmp signaling in oral and dental epithelia of the keratin 14-Noggin transgenic mouse. We observed a wide spectrum of tooth phenotypes. The dental formula changed from 1.0.0.3/1.0.0.3 to 1.0.0.2(1)/1.0.0.0. All mandibular and M3 maxillary molars were selectively lost because of the developmental block at the early bud stage. First and second maxillary molars were reduced in size, exhibited altered crown patterns, and failed to form multiple roots. In these mice, incisors were not transformed into molars. Histogenesis and differentiation of ameloblasts and odontoblasts in molars and incisors were abnormal. Lack of enamel caused misocclusion of incisors, leading to deformation and enlargement in size. Therefore, subtle differences in the level, distribution, and timing of signaling molecules can have major morphoregulatory consequences. Modulation of Bmp signaling exemplifies morphoregulation hypothesis: simple alteration of key signaling pathways can be used to transform a prototypical conical-shaped tooth into one with complex morphology. The involvement of related pathways and the implication of morphoregulation in tooth evolution are discussed.
Plikus M V; Zeichner-David M; Mayer J A; Reyna J; Bringas P; Thewissen J G M; Snead M L; Chai Y; Chuong C M
Evolution & Development
2005
2005-09
Journal Article
<a href="http://doi.org/10.1111/j.1525-142X.2005.05048.x" target="_blank" rel="noreferrer noopener">10.1111/j.1525-142X.2005.05048.x</a>
Temperature regulates limb length in homeotherms by directly modulating cartilage growth
Allen's Rule; blood-flow; body size; bone; bone growth; bone tissue culture; cartilage biology; differentiation; endoplasmic-reticulum stress; environmental-temperature; fluorescent microsphere method; mouse; plate; proliferation; Science & Technology - Other Topics; tail-length; thermoregulation
Allen's Rule documents a century-old biological observation that strong positive correlations exist among latitude, ambient temperature, and limb length in mammals. Although genetic selection for thermoregulatory adaptation is frequently presumed to be the primary basis of this phenomenon, important but frequently overlooked research has shown that appendage outgrowth is also markedly influenced by environmental temperature. Alteration of limb blood flow via vasoconstriction/vasodilation is the current default hypothesis for this growth plasticity, but here we show that tissue perfusion does not fully account for differences in extremity elongation in mice. We show that peripheral tissue temperature closely reflects housing temperature in vivo, and we demonstrate that chondrocyte proliferation and extracellular matrix volume strongly correlate with tissue temperature in metatarsals cultured without vasculature in vitro. Taken together, these data suggest that vasomotor changes likely modulate extremity growth indirectly, via their effects on appendage temperature, rather than vascular nutrient delivery. When combined with classic evolutionary theory, especially genetic assimilation, these results provide a potentially comprehensive explanation of Allen's Rule, and may substantially impact our understanding of phenotypic variation in living and extinct mammals, including humans.
Serrat M A; King D; Lovejoy C O
Proceedings of the National Academy of Sciences of the United States of America
2008
2008-12
Journal Article
<a href="http://doi.org/10.1073/pnas.0803319105" target="_blank" rel="noreferrer noopener">10.1073/pnas.0803319105</a>
Ultrastructural and cytochemical evaluation of sepsis-induced changes in the rat pulmonary intravascular mononuclear phagocytes
acid-phosphatase; Anatomy & Morphology; Blood; cells; coagulation; differentiation; endotoxin; expression; host defence; human macrophage; lung uptake; monocytes; mononuclear phagocyte system; surface-coat
Sepsis stimulates an increase in the number and activity of mononuclear phagocytes in systemic host-defence organs. The present study was conducted to define the ultrastructural and cytochemical characteristics of the mononuclear phagocytes that sequester in the lung microvasculature of septic rats, Fourteen rats were challenged with a single intraperitoneal injection of saline (0.5 ml/100 g), E. coli (2 x 10(7)/100 g) or glucan (4 mg/100 g), and euthanased 2, 4, or 7 d later. The lungs were inflation fixed and processed for transmission electron microscopy. Cellular morphology was used to identify the intravascular mononuclear phagocytes and acid phosphatase (AcPase) expression was monitored as an index of cellular differentiation and activation. Control rats contained a limited number of monocytes in the pulmonary vasculature. In contrast, large numbers of activated mononuclear phagocytes were seen in the microvasculature within 48 h of treatment with either microbial product. The recruited pulmonary intravascular mononuclear phagocytes (PIMP) exhibited AcPase-reactive Golgi complexes, accumulation of secretory vesicles and other features of cell activation consistent with enhanced biosynthetic activity. Subsequent electron microscopy, conducted 4 and 7 d posttreatment, suggested that a progressive decline in the number and activity of PIMPs then occurred. In order to quantify the sepsis-induced accumulation of AcPase-positive PIMP, the experimental challenges were repeated in 11 rats and, 48 h later, tissue samples were evaluated by light microscopy for tartrate-insensitive acid phosphatase. Control rats exhibited 0.148 +/- 0.107 AcPase-positive PIMP/alveoli. E. coli and glucan challenged animals exhibited significant (P < 0.01) increases in AcPase-positive mononuclear phagocytes, with 0.782+/-0.073 and 0.636+/-0.170 PIMP/alveoli respectively, The results demonstrate that focal sepsis stimulates a significant, but transient, recruitment of activated mononuclear phagocytes into the rat pulmonary microvasculature.
Singh B; Doane K J; Niehaus G D
Journal of Anatomy
1998
1998-01
Journal Article
<a href="http://doi.org/10.1046/j.1469-7580.1998.19210013.x" target="_blank" rel="noreferrer noopener">10.1046/j.1469-7580.1998.19210013.x</a>
Aldosterone stimulates proliferation of cardiac fibroblasts by activating Ki-RasA and MAPK1/2 signaling
angiotensin-ii; Cardiovascular System & Cardiology; differentiation; fibrosis; gene-expression; Heart failure; identification; induction; Kirsten Ras; mineralocorticoid; mitogen-activated protein kinase; myofibroblast; na+ reabsorption; Physiology; receptor; spironolactone; transcription
Aldosterone plays a pathological role in cardiac fibrosis by directly affecting cardiac fibroblasts. Understanding of the cellular mechanisms of aldosterone action in cardiac fibroblasts, however, is rudimentary. One possibility is that aldosterone promotes proliferation of cardiac fibroblasts by activating specific cellular signaling cascades. The current study tests whether aldosterone stimulates proliferation of isolated adult rat cardiac myofibroblasts (RCF) by activating Kirsten Ras (Ki-RasA) and its effector, the MAPK1/2 cascade. Aldosterone (10 nM) significantly increased RCF proliferation. This action was sensitive to the mineralocorticoid receptor (MR) antagonist spironolactone. Expression of MR in RCF and the whole rat heart was confirmed by immunoblotting. Aldosterone significantly increased absolute and active (GTP bound) Ki-RasA levels in RCF. Aldosterone, in addition, significantly increased phospho-c-Raf and phospho-MAPK1/2. The effects of aldosterone on Ki-RasA and phospho-c-Raf proteins were inhibited by spironolactone but not RU-486, suggesting that aldosterone acts via MR. Inhibitors of MEK1/2 and c-Raf prevented aldosterone-induced activation of MAPK1/2 and proliferation. These results show that aldosterone directly increases RCF proliferation through MR-dependent activation of Ki-RasA and its effector, the MAPK1/2 cascade. Activation of cardiac fibroblasts through such a cascade may play a role in the pathological actions exerted by aldosterone on the heart.
Stockand J D; Meszaros J G
American Journal of Physiology-Heart and Circulatory Physiology
2003
2003-01
Journal Article
<a href="http://doi.org/10.1152/ajpheart.00421.2002" target="_blank" rel="noreferrer noopener">10.1152/ajpheart.00421.2002</a>
INSITU HYBRIDIZATION STUDY OF OBESITY-ASSOCIATED ALTERATION IN GROWTH-HORMONE MESSENGER-RNA LEVELS
differentiation; Endocrinology & Metabolism; expression; fetal-rat; gene-transcription; glucocorticoid hormones; growth hormone; insitu hybridization; insulin; lean zucker rats; messenger-rna; Nutrition & Dietetics; pituitary-tumor cells; ribonucleic-acid; triiodothyronine
In order to investigate whether the impaired GH secretion associated with obesity is due to a pituitary disorder we studied GH mRNA levels by in situ hybridization in genetically obese and lean Zucker rats. The levels of GH mRNA were at least two fold lower in obese rats in comparison to that in lean controls as quantified by both the scanning of autoradiographs of tissue sections and Northern blot analysis. Quantification of somatotrophs revealed no significant difference in their number between lean and obese rat pituitaries. It is therefore likely that the attenuated GH mRNA levels in genetically obese Zucker rats are due to a decrease in GH transcripts per somatotroph rather than a result of a pituitary defect involving a preferential decrease in somatotroph population.
Ahmad I; Steggles A W; Finkelstein J A
International Journal of Obesity
1992
1992-06
Journal Article or Conference Abstract Publication
n/a
Developmental And Genetic Influences Upon Gender Differences In Methamphetamine-induced Nigrostriatal Dopaminergic Neurotoxicity
bdnf mutant mice; brain; brain-derived neurotrophic factor (BDNF); differentiation; dopamine; estrogen; female mice; gonadal-hormones; messenger-rna; mptp-induced neurotoxicity; neurodegeneration; neuroprotection; neurotrophic factor; parkinsons-disease; sexual; sexual differences; testosterone; ventral mesencephalon
Dluzen D E; McDermott J L
Current Status of Drug Dependence / Abuse Studies: Cellular and Molecular Mechanisms of Drugs of Abuse and Neurotoxicity
2004
2004
Book Chapter
n/a
Bcl-2 Regulates Chondrocyte Morphology And Aggrecan Gene Expression Independent Of Caspase Activation And Full Apoptosis
aging; apoptosis; Biochemistry & Molecular Biology; cartilage; Cell Biology; chondrocyte; differentiation; expression; gene regulation; growth-factor; hl-60 cells; hormone-related peptide; nerve; nf-kappa-b; programmed cell-death; protein; skeletal development; targeted disruption
Feng L X; Balakir R; Precht P; Horton W E
Journal of Cellular Biochemistry
1999
1999-09
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1002/(sici)1097-4644(19990915)74:4%3C576::aid-jcb7%3E3.3.co;2-e" target="_blank" rel="noreferrer noopener">10.1002/(sici)1097-4644(19990915)74:4%3C576::aid-jcb7%3E3.3.co;2-e</a>
2.5d Constructs For Characterizing Phase Separated Polymer Blend Surface Morphology In Tissue Engineering Scaffolds
2; 3d; 5D scaffolds; cell-shape; differentiation; Engineering; L-lactide); Materials Science; mechanical-properties; poly(D; poly(e-caprolactone); polymer blends; porosity; proliferation; topography
Marszalek J E; Simon C G; Thodeti C; Adapala R K; Murthy A; Karim A
Journal of Biomedical Materials Research Part A
2013
2013-05
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1002/jbm.a.34439" target="_blank" rel="noreferrer noopener">10.1002/jbm.a.34439</a>
Experiments With Osteoblasts Cultured Under Hypergravity Conditions
bone; cells; differentiation; Engineering; expression; human dermal fibroblasts; in-vitro; Mechanics; microgravity; rats; space-flight; system; Thermodynamics
To understand further the role of gravity in osteoblast attachment, osteoblasts were subjected to hypergravity conditions in vitro. Scanning electron microscopy of all confluent coverslips from FPA units show that the number of attached osteoblasts was similar among gravitational levels and growth durations (similar to90 cells/microscopic field). Specifically. confluent 1.0G control cultures contained an average of 91+/-8 cells/field, 3.3G samples had 88+/-8 cells/field, and 4.0G cultures averaged 90+/-7 cells/field. The sparsely plated cultures assessed by immunohistochemistry also had similar numbers of cells at each time point (1.0G was similar to 3.3 and 4.0G), but cell number changed from one time point to the next as those cells proliferated Immunohistochemistry of centrifuged samples showed an increase in number (up to 160% increase) and thickness (tip to 49% increase) of actin fibers, a decrease in intensity of fibro-nectin fluorescence (18-23% decrease) and an increase in number of vinculin bulbs (202-374% increase in number of vinculin bulbs/area). While hypergravity exposure did not alter the number of attached osteoblasts, it did result in altered actin, fibronectin, and vinculin elements, changing some aspects of osteoblast-substrate adhesion.
Kacena M A; Todd P; Gerstenfeld L C; Landis W J
Microgravity Science and Technology
2004
2004
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1007/bf02870949" target="_blank" rel="noreferrer noopener">10.1007/bf02870949</a>
Osteoblasts Subjected To Spaceflight And Simulated Space Shuttle Launch Conditions
acceleration; bone cells; bone-formation; Cell Biology; cells; Developmental Biology; differentiation; flight; gene-expression; growing rats; in-vitro; messenger-rna expression; microgravity; vibration; weightlessness
To understand further the effects of spaceflight on osteoblast-enriched cultures, normal chicken calvarial osteoblasts were flown aboard shuttle flight STS-77, and the total number of attached cells was determined. Spaceflight and control cultures were chemically fixed 3 h and 3 d after launch. These fixed cultures were processed for scanning electron microscopy (SEM). The SEM analysis showed that with just 3 d of exposure to spaceflight, coverslip cultures contained 300 +/- 100 cells/mm(2), whereas 1G control samples contained a confluent monolayer of cells (2400 +/- 200 cells/mm(2)). Although the cultures flown in space experienced a drastic decline in cell number in just 3 d, without further experimentation it was impossible to determine whether the decline was a result of microgravity, the harsh launch environment, or some combination of these factors. Therefore, this research attempted to address the effect of launch by subjecting osteoblasts to conditions simulating shuttle launch accelerations, noise, and vibrations. No differences, compared with controls, were seen in the number of total or viable cells after exposure to these various launch conditions. Taken together, these data indicate that the magnitude of gravitational loading (3G maximum) and vibration (7.83G rms maximum) resulting from launch does not adversely affect osteoblasts in terms of total or viable cell number immediately, but launch conditions, or the microgravity environment itself, may start a cascade of events that over several d contributes to cell loss.
Kacena M A; Todd P; Landis W J
In Vitro Cellular & Developmental Biology-Animal
2003
2003-11
Journal Article or Conference Abstract Publication
n/a
Formation Of Muscle-spindles In The Absence Of Motor Innervation
afferent; differentiation; efferent; fibers; intrafusal muscle fiber; muscle; nerve; Neurosciences & Neurology; rat; spindle development
Whether muscle spindles can form in muscles innervated only by afferents was investigated by removing the lumbosacral segment of the spinal cord immediately after crushing the nerve to the medial gastrocnemius (MG) muscle in newborn rats, and administering nerve growth factor for 10 days afterwards. The nerve-crushed MG muscles reinnervated by afferents in the absence of motor innervation were examined at postnatal (P) days 7, 9 and 30 for the presence of spindles by light and electron miscroscope. Reinnervated MG muscles contained spindle-like encapsulations of 1-4 fibers at 7, 9 and 30 days after the nerve crush. The number of spindles exceeded that of normal MG muscles, suggestive of de novo formation of spindles. All nerve-muscle contacts in the spindles had features of sensory endings, and intrafusal fibers expressed the spindle-specific slow-tonic myosin heavy chain (MHC) isoform at P30. No motor endplates were visible on any muscle fibers and extrafusal fibers were atrophied, as would be predicted in the absence of motor innervation. Thus, efferents are not essential for the formation and differentiation of muscle spindles in reinnervated muscles of neonatal rats.
Kucera J; Walro J M
Neuroscience Letters
1992
1992-09
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1016/0304-3940(92)90200-q" target="_blank" rel="noreferrer noopener">10.1016/0304-3940(92)90200-q</a>
Expression Of Type-specific Mhc Isoforms In Rat Intrafusal Muscle-fibers
cat; Cell Biology; differentiation; fiber types; histochemistry; identification; immunocytochemistry; innervation; intrafusal; monoclonal antimyosin antibodies; monoclonal-antibody; motor; muscle fiber typing; muscle spindles; myosin heavy-chain; rat skeletal muscle; skeletal-muscle; spindles
Myosin heavy chain (MHC) expression by intrafusal fibers was studied by immunocytochemistry to determine how closely it parallels MHC expression by extrafusal fibers in the soleus and tibialis anterior muscles of the rat. Among the MHC isoforms expressed in extrafusal fibers, only the slow-twitch MHC of Type 1 extrafusal fibers was expressed along much of the fibers. Monoclonal antibodies (MAb) specific for this MHC bound to the entire length of bag2 fibers and the extracapsular region of bag1 fibers. The fast-twitch MHC isoform strongly expressed by bag2 and chain fibers had an epitope not recognized by MAb to the MHC isoforms characteristic of developing muscle fibers or the three subtypes (2A, 2B, 2X) of Type 2 extrafusal fibers. Therefore, intrafusal fibers may express a fast-twitch MHC that is not expressed by extrafusal fibers. Unlike extrafusal fibers, all three intrafusal fiber types bound MAb generated against mammalian heart and chicken limb muscles. The similarity of the fast-twitch MHC of bag2 and chain fibers and the slow-tonic MHC of bag1 and bag2 fibers to the MHC isoforms expressed in avian extrafusal fibers suggests that phylogenetically primitive MHCs might persist in intrafusal fibers. Data are discussed relative to the origin and regional regulation of MHC isoforms in intrafusal and extrafusal fibers of rat hindlimb muscles.
Kucera J; Walro J M; Gorza L
Journal of Histochemistry & Cytochemistry
1992
1992-02
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1177/40.2.1552171" target="_blank" rel="noreferrer noopener">10.1177/40.2.1552171</a>
Spaceflight Effects On Cultured Embryonic Chick Bone Cells
biomechanics; bone adaptation; collagen; differentiation; Endocrinology & Metabolism; in-vitro; mechanical strain; messenger-rna expression; microgravity; osteoblast; osteoblasts; osteopontin; restriction; signal-transduction; space-flight
A model calcifying system of primary osteoblast cell cultures derived from normal embryonic chicken calvaria has been flown aboard the shuttle, Endeavour, during the National Aeronautics and Space Administration (NASA) mission STS-59 (April 9-20, 1994) to characterize unloading and other spaceflight effects on the bone cells. Aliquots of cells (similar to 7 x 10(6)) grown in Dulbecco's modified Eagle's medium (DMEM) + 10% fetal bovine serum (FBS) were mixed with microcarrier beads, inoculated into cartridge culture units of artificial hollow fiber capillaries, and carried on the shuttle. To promote cell differentiation, cartridge media were supplemented with 12.5 mu g/ml ascorbate and 10 mM P-glycerophosphate for varying time periods before and during Right. Four cartridges contained cells from 17-day-old embryos grown for 5 days in the presence of ascorbate prior to launch (defined as flight cells committed to the osteoblastic lineage) and four cartridges supported cells from 14-day-old embryos grown for 10 days with ascorbate before launch (uncommitted flight cells). Eight cartridges prepared in the same manner were maintained under normal gravity throughout the Right (control cells) and four additional identical cartridges under normal gravity were terminated on the day of launch (basal cells). From shuttle launch to landing, all cartridges were contained in closed hardware units maintaining 5% CO2, 37 degrees C, and media delivery at a rate of similar to 1.5 ml/6 h. During day 3 and day 5 of flight, duplicate aliquots of conditioned media and accumulated cell products were collected in both the Right and the control hardware units. At the mission end, comparisons among Right, basal, and control samples were made in cell metabolism gene expression for type I collagen and osteocalcin, and ultrastructure. Both committed and uncommitted flight cells were metabolically active, as measured by glucose uptake and lactate production, at approximately the same statistical levels as control counterparts. Flight cells elaborated a less extensive extracellular matrix, evidenced by a reduced collagen gene expression and collagen protein appearance compared with controls. Osteocalcin was expressed by all cells, a result indicating progressive differentiation of both flight and control osteoblasts, but its message levels also were reduced in flight cells compared with ground samples. This finding suggested that osteoblasts subjected to flight followed a slower progression toward a differentiated function. The summary of data indicates that spaceflight, including microgravity exposure, demonstrably affects bone cells by down-regulating type I collagen and osteocalcin gene expression and thereby inhibiting expression of the osteogenic phenotype notably by committed osteoblasts. The information is important for insight into the response of bone cells to changes of gravity and of force in general.
Landis W J; Hodgens K J; Block D; Toma C D; Gerstenfeld L C
Journal of Bone and Mineral Research
2000
2000-06
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1359/jbmr.2000.15.6.1099" target="_blank" rel="noreferrer noopener">10.1359/jbmr.2000.15.6.1099</a>
Neurotrophin-3 Ameliorates Sensory-motor Deficits In Er81-deficient Mice
afferents; Anatomy & Morphology; connections; Developmental Biology; differentiation; ER81; ETS; innervation; motor neurons; muscle spindles; muscle spindles; mutant mice; neurons; neurotrophins; NT3; rat; regeneration; sensory neurons; specification; spinal-cord; transcription factors
Two factors, the ETS transcription factor ER81 and skeletal muscle-derived neurotrophin-3 (NT3), are essential for the formation of muscle spindles and the function of spindle afferent-motoneuron synapses in the spinal cord. Spindles either degenerate completely or are abnormal, and spindle afferents fail to project to spinal motoneurons in Er81 null mice; however, the interactions between ER81 and NT3 during the processes of afferent neuron and muscle spindle development are poorly understood. To examine if overexpression of NT3 in muscle rescues spindles and afferent-motoneuron connectivity in the absence of ER81, we generated myoNT3;Er81(-/-) double-mutant mice that selectively overexpress NT3 in muscle in the absence of ER81. Spindle reflex arcs in myoNT3;Er81(-/-) mutants differed greatly from Er81 null mice. Muscle spindle densities were greater and more afferents projected into the ventral spinal cord in myoNT3;Er81(-/-) mice. Spindles of myoNT3,Er81(-/-) muscles responded normally to repetitive muscle taps, and the monosynaptic inputs from la afferents to motoneurons, grossly reduced in Er81(-/-) mutants, were restored to wild-type levels in myoNT3,Er81(-/-) mice. Thus, an excess of muscle-derived NT3 reverses deficits in spindle numbers and afferent function induced by the absence of ER81. We conclude that muscle-derived NT3 can modulate spindle density and afferent-motoneuron connectivity independently of ER81.
Li L Y; Wang Z; Sedy J; Quazi R; Walro J M; Frank E; Kucera J
Developmental Dynamics
2006
2006-11
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1002/dvdy.20964" target="_blank" rel="noreferrer noopener">10.1002/dvdy.20964</a>
Knockdown Of Leptin A Expression Dramatically Alters Zebrafish Development
atlantic salmon; Auditory; bhlh genes; bone; carp cyprinus-carpio; cell fate specification; central-nervous-system; cloning; danio-rerio; differentiation; Endocrinology & Metabolism; gene; metabolism; n-cadherin; receptor; sensory ganglia; Visual; visual-system
Using morpholino antisense oligonucleotide (MO) technology, we blocked leptin A or leptin receptor expression in embryonic zebrafish, and analyzed consequences of leptin A knock-down on fish development. Embryos injected with leptin A or leptin receptor MOs (leptin A or leptin receptor morphants) had smaller bodies and eyes, undeveloped inner ear, enlarged pericardial cavity, curved body and/or tail and larger yolk compared to control embryos of the same stages. The defects persisted in 6-9 days old larvae. We found that blocking leptin A function had little effect on the development of early brain (1 day old), but differentiation of both the morphant dorsal brain and retinal cells was severely disrupted in older (2 days old) embryos. Despite the enlarged pericardial cavity, differentiation of cardiac cells appeared to be similar to control embryos. Formation of the morphants' inner ear is also severely disrupted, which corroborates existing reports of leptin receptor expression in inner ear of both zebrafish and mammals. Co-injection of leptin A MO and recombinant leptin results in partial rescue of the wild-type phenotype. Our results suggest that leptin A plays distinct roles in zebrafish development. (c) 2012 Elsevier Inc. All rights reserved.
Liu Q; Dalman M; Chen Y; Akhter M; Brahmandam S; Patel Y; Lowe J; Thakkar M; Gregory A V; Phelps D; Riley C; Londraville R L
General and Comparative Endocrinology
2012
2012-09
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1016/j.ygcen.2012.07.011" target="_blank" rel="noreferrer noopener">10.1016/j.ygcen.2012.07.011</a>