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1.
Arq. bras. med. vet. zootec. (Online) ; 72(4): 1145-1153, July-Aug. 2020. tab, ilus
Artigo em Português | LILACS, VETINDEX | ID: biblio-1131471

RESUMO

O presente estudo avaliou o perfil mineral de Cálcio (Ca), Cobre (Cu) e Zinco (Zn) no estojo córneo pré e pós-desmame e sua associação com pigmentação, gênero e idade de potros da raça Crioula criados em pastagens nativas no Rio Grande do Sul. Foram coletadas amostras do casco de potros da raça Crioula 41 dias pré e 28 dias pós-desmame. Os teores de Ca, Cu e Zn variaram no casco fetal (571,0±39,4; 14,5±7,6 e 130,0±30,5mg/kg, respectivamente; P<0,05) e no definitivo (653,0±169,2; 33,8±11,5 e 69,3±36,8mg/kg, respectivamente; P<0,05), no pré (620,0±184; 17,2±21,2 e 103,0±75,5mg/kg, respectivamente; P<0,05) e no pós-desmame (517,5±181; 0 e 79,0±41,7mg/kg, respectivamente; P<0,05). Houve associação positiva (P<0,05) com a faixa etária no pré-desmame para Ca (r=0,5) e Cu (r=0,57), e negativa para Zn (r=-0,69; P<0,05). No pós-desmame, houve associação positiva (P<0,05) para Ca (r=0,36) e Zn (r=0,64) e negativa para Cu (r=-0,39; P<0,05). Tanto a pigmentação quanto o gênero não afetaram o perfil mineral. Conclui-se que há diferenças nas concentrações de Ca, Cu e Zn na epiderme do casco de potros da raça Crioula no pré e pós-desmame, independentemente da pigmentação e do gênero, onde as concentrações de Ca e Cu aumentam com a idade, enquanto as de Zn diminuem.(AU)


The aim of this study was to evaluate the mineral profile of Ca, Cu and Zn in the hoof horny capsule at pre and post-weaning and its association with pigmentation, gender and age range of Crioulo foals raised in native pastures in RS. Samples were collected from the epidermis of the Crioulo foal's hoof at two times, 41 pre and 28 post-weaning. The contents of Ca, Cu, Zn Varied in the fetal hoof ( 571.0±139.4, 14.5±7.6 and 130.0±30.5mg/kg, respectively, P<0.05) and definitive (653.0±169.2, 33.8±11.5 and 69.3±36.8mg/kg, respectively, P<0.05), in the pre (620.0±184, 17.2±21.2 and103.0±75.5mg/kg, respectively, P<0.05) and post-weaning (517.5±181, 0.1 and 79.0±41.7mg/kg, respectively, P<0.05).There was a positive association (P<0.05) with a preweaning age for Ca (r=0.5) and Cu (r=0.57) and negative for Zn (r=-0.69, P<0.05). In the post weaning there was a positive association (P<0.05) for Ca (r=0.36) and Zn (r=0.64) and negative for Cu (r=-0.39; P<0.05). Neither pigmentation nor gender affected the mineral profile. It is concluded that there are differences in Ca, Cu, Zn concentrations in the epidermis of foals of the crioulo breed at the pre and post weaning, regardless of pigmentation and sex, where Ca and Cu concentrations increase with age, while Zn concentrations decrease.(AU)


Assuntos
Animais , Pigmentação da Pele/fisiologia , Casco e Garras/citologia , Cavalos/crescimento & desenvolvimento , Minerais , Zinco , Cálcio , Cobre , Queratinas
2.
PLoS One ; 14(9): e0219234, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31550264

RESUMO

The equine hoof inner epithelium is folded into primary and secondary epidermal lamellae which increase the dermo-epidermal junction surface area of the hoof and can be affected by laminitis, a common disease of equids. Two keratin proteins (K), K42 and K124, are the most abundant keratins in the hoof lamellar tissue of Equus caballus. We hypothesize that these keratins are lamellar tissue-specific and could serve as differentiation- and disease-specific markers. Our objective was to characterize the expression of K42 and K124 in equine stratified epithelia and to generate monoclonal antibodies against K42 and K124. By RT-PCR analysis, keratin gene (KRT) KRT42 and KRT124 expression was present in lamellar tissue, but not cornea, haired skin, or hoof coronet. In situ hybridization studies showed that KRT124 localized to the suprabasal and, to a lesser extent, basal cells of the lamellae, was absent from haired skin and hoof coronet, and abruptly transitions from KRT124-negative coronet to KRT124-positive proximal lamellae. A monoclonal antibody generated against full-length recombinant equine K42 detected a lamellar keratin of the appropriate size, but also cross-reacted with other epidermal keratins. Three monoclonal antibodies generated against N- and C-terminal K124 peptides detected a band of the appropriate size in lamellar tissue and did not cross-react with proteins from haired skin, corneal limbus, hoof coronet, tongue, glabrous skin, oral mucosa, or chestnut on immunoblots. K124 localized to lamellar cells by indirect immunofluorescence. This is the first study to demonstrate the localization and expression of a hoof lamellar-specific keratin, K124, and to validate anti-K124 monoclonal antibodies.


Assuntos
Epiderme/metabolismo , Expressão Gênica , Casco e Garras/metabolismo , Queratinas/genética , Animais , Biomarcadores , Casco e Garras/anatomia & histologia , Casco e Garras/citologia , Cavalos , Imuno-Histoquímica , Especificidade de Órgãos/genética , Isoformas de Proteínas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
3.
BMC Vet Res ; 15(1): 127, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31039823

RESUMO

BACKGROUND: Laminitis is considered as one of the most important causes of hoof lameness in dairy cows, which can lead to enormous economic losses. However, the etiology and pathogenesis of laminitis have not been clarified yet. Besides, it is of great significant to find alternative herbs for the prevention and treatment of dairy hooves to avoid the antibiotic abuse. In this study, the primary hoof dermal cells of dairy cows were isolated, the inflammatory model was induced by LPS, and treated with silymarin to find whether silymarin has protective effect on the inflammatory dermal cells. The viability of dermal cells, the levels of IL-1ß and TNF-α, the degree of p65 NF-κB and p38 MAPK phosphorylation, the expressions of CYP3A4 and CYP1A1 were measured. RESULTS: Hoof dermal cells of dairy cows were successfully isolated and cultured by tissue adherent culture method. Certain concentrations of LPS can increase the levels of IL-1ß and TNF-α, promote the phosphorylation of p65 NF-κB and p38 MAPK, and inhibit the mRNA expressions of CYP3A4 and CYP1A1. The optimal concentration for LPS to establish a hoof dermal cells inflammatory model was 10 µg/mL. Certain concentrations of silymarin can markedly decrease the secretions of IL-1ß and TNF-α, inhibit the phosphorylation of p65 NF-κB and p38 MAPK, and promote the mRNA expressions of CYP3A4 and CYP1A1 in LPS-induced dermal inflammatory model. CONCLUSIONS: LPS can be used for inducing the hoof dermal cells inflammatory model of dairy cows. Silymarin has protective effects on the LPS-induced inflammatory model.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Casco e Garras/citologia , Silimarina/farmacologia , Fator de Transcrição RelA/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP3A/genética , Citocromo P-450 CYP3A/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Derme/citologia , Derme/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Casco e Garras/efeitos dos fármacos , Inflamação/induzido quimicamente , Interleucina-1beta/metabolismo , Lipopolissacarídeos/toxicidade , Fosforilação , Fator de Transcrição RelA/genética , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/genética
4.
Vet Pathol ; 54(4): 661-668, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28622496

RESUMO

Hoof canker is described as progressive pododermatitis of the equine hoof with absent epidermal cornification and extensive proliferation of the dermal papillary body; however, in-depth research on the type of proliferative activity has not yet been reported. The aim of the present study was to determine cell-specific proliferation patterns together with morphological analysis of hoof canker tissue. Tissues removed during surgery from 19 horses presented for treatment of canker were compared with similar postmortem tissues of healthy hooves of 10 horses. Morphological alterations visible in light microscopy were assessed semiquantitatively and graded for severity. Proliferative activity was evaluated by means of anti-PCNA (proliferative cell nuclear antigen) and anti-Ki67 immunohistochemistry. Histologically, canker tissue showed 5 major morphological alterations-the presence of lacunae, vacuoles, giant cells, hemorrhage, and inflammation-not seen in control tissue. Also, there was a notable koilocytotic appearance of keratinocytes in canker tissue. Immunohistochemistry revealed increased levels of PCNA protein expression in keratinocytes and fibroblasts of canker tissue compared with control tissue. In control tissue, keratinocytes showed higher levels of Ki67 compared with canker tissue, while the dermal fibroblasts of both groups showed similar levels of Ki67, indicating similar proliferative activity of less than 3% of total dermal fibroblasts. These results demonstrate that, in contrast to previous reports, there is no evidence for increased proliferative activity of the dermal papillary body associated with hoof canker. Increased levels of PCNA protein expression and morphological alterations indicate that dysregulation of keratinocyte differentiation constitutes a key event in equine hoof canker development.


Assuntos
Doenças do Pé/veterinária , Casco e Garras/patologia , Doenças dos Cavalos/patologia , Animais , Proliferação de Células , Feminino , Fibroblastos/patologia , Doenças do Pé/patologia , Casco e Garras/citologia , Cavalos , Queratinócitos/patologia , Antígeno Ki-67/metabolismo , Masculino , Antígeno Nuclear de Célula em Proliferação/metabolismo
5.
Toxins (Basel) ; 8(4): 89, 2016 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-27023602

RESUMO

One of the most important hoof diseases is laminitis. Yet, the pathology of laminitis is not fully understood. Different bacterial toxins, e.g. endotoxins or exotoxins, seem to play an important role. Additionally, ingestion of mycotoxins, toxic secondary metabolites of fungi, might contribute to the onset of laminitis. In this respect, fumonsins are of special interest since horses are regarded as species most susceptible to this group of mycotoxins. The aim of our study was to investigate the influence of fumonisin B1 (FB1) on primary isolated epidermal and dermal hoof cells, as well as on the lamellar tissue integrity and sphingolipid metabolism of hoof explants in vitro. There was no effect of FB1 at any concentration on dermal or epidermal cells. However, FB1 significantly reduced the separation force of explants after 24 h of incubation. The Sa/So ratio was significantly increased in supernatants of explants incubated with FB1 (2.5-10 µg/mL) after 24 h. Observed effects on Sa/So ratio were linked to significantly increased sphinganine concentrations. Our study showed that FB1 impairs the sphingolipid metabolism of explants and reduces lamellar integrity at non-cytotoxic concentrations. FB1 might, therefore, affect hoof health. Further in vitro and in vivo studies are necessary to elucidate the effects of FB1 on the equine hoof in more detail.


Assuntos
Fumonisinas/toxicidade , Casco e Garras/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Casco e Garras/citologia , Casco e Garras/metabolismo , Casco e Garras/patologia , Cavalos , Esfingolipídeos/metabolismo
6.
Proc Natl Acad Sci U S A ; 112(43): 13249-54, 2015 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-26460010

RESUMO

The tips of the digits of some mammals, including human infants and mice, are capable of complete regeneration after injury. This process is reliant on the presence of the overlaying nail organ and is mediated by a proliferative blastema. Epithelial Wnt/ß-catenin signaling has been shown to be necessary for mouse digit tip regeneration. Here, we report on Lgr5 and Lgr6 (leucine-rich repeat-containing G protein-coupled receptor 5 and 6), two important agonists of the Wnt pathway that are known to be markers of several epithelial stem cell populations. We find that Lgr5 is expressed in a dermal population of cells adjacent to the specialized epithelia surrounding the keratinized nail plate. Moreover, Lgr5-expressing cells contribute to this dermis, but not the blastema, during digit tip regeneration. In contrast, we find that Lgr6 is expressed within cells of the nail matrix portion of the nail epithelium, as well as in a subset of cells in the bone and eccrine sweat glands. Genetic lineage analysis reveals that Lgr6-expressing cells give rise to the nail during homeostatic growth, demonstrating that Lgr6 is a marker of nail stem cells. Moreover, Lgr6-expressing cells contribute to the blastema, suggesting a potential direct role for Lgr6-expressing cells during digit tip regeneration. This role is confirmed by analysis of Lgr6-deficient mice, which have both a nail and bone regeneration defect.


Assuntos
Células Epiteliais/metabolismo , Casco e Garras/fisiologia , Receptores Acoplados a Proteínas-G/metabolismo , Regeneração/fisiologia , Dedos do Pé/fisiologia , Animais , Antraquinonas , Primers do DNA/genética , Galactosídeos , Técnicas de Inativação de Genes , Proteínas de Fluorescência Verde/metabolismo , Membro Posterior/fisiologia , Técnicas Histológicas , Casco e Garras/citologia , Imuno-Histoquímica , Indóis , Camundongos , Camundongos Transgênicos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
7.
Vet Dermatol ; 26(4): 213-e47, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25963063

RESUMO

BACKGROUND: The limited characterization of equine skin, eye and hoof epithelial stem cell (ESC) and differentiation markers impedes the investigation of the physiology and pathophysiology of these tissues. HYPOTHESIS/OBJECTIVES: To characterize ESC and differentiation marker expression in epithelial tissues of the equine eye, haired skin and hoof capsule. METHODS: Indirect immunofluorescence microscopy and immunoblotting were used to detect expression and tissue localization of keratin (K) isoforms K3, K10, K14 and K124, the transcription factor p63 (a marker of ESCs) and phosphorylated p63 [pp63; a marker of ESC transition to transit-amplifying (TA) cell] in epithelial tissues of the foot (haired skin, hoof coronet and hoof lamellae) and the eye (limbus and cornea). RESULTS: Expression of K14 was restricted to the basal layer of epidermal lamellae and to basal and adjacent suprabasal layers of the haired skin, coronet and corneal limbus. Coronary and lamellar epidermis was negative for both K3 and K10, which were expressed in the cornea/limbus epithelium and haired skin epidermis, respectively. Variable expression of p63 with relatively low to high levels of phosphorylation was detected in individual basal and suprabasal cells of all epithelial tissues examined. CONCLUSIONS: To the best of the author's knowledge, this is the first report of the characterization of tissue-specific keratin marker expression and the localization of putative epithelial progenitor cell populations, including ESCs (high p63 expression with low pp63 levels) and TA cells (high expression of both p63 and pp63), in the horse. These results will aid further investigation of epidermal and corneal epithelial biology and regenerative therapies in horses.


Assuntos
Diferenciação Celular/fisiologia , Córnea/citologia , Casco e Garras/citologia , Cavalos/anatomia & histologia , Pele/citologia , Células-Tronco/fisiologia , Animais , Antígenos de Diferenciação/metabolismo , Córnea/metabolismo , Epitélio/metabolismo , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Casco e Garras/metabolismo , Cavalos/metabolismo , Immunoblotting , Queratinas/metabolismo , Masculino , Pele/metabolismo , Células-Tronco/metabolismo
8.
Proc Natl Acad Sci U S A ; 111(42): 15114-9, 2014 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-25277970

RESUMO

Regulation of adult stem cells (SCs) is fundamental for organ maintenance and tissue regeneration. On the body surface, different ectodermal organs exhibit distinctive modes of regeneration and the dynamics of their SC homeostasis remain to be unraveled. A slow cycling characteristic has been used to identify SCs in hair follicles and sweat glands; however, whether a quiescent population exists in continuously growing nails remains unknown. Using an in vivo label retaining cells (LRCs) system, we detected an unreported population of quiescent cells within the basal layer of the nail proximal fold, organized in a ring-like configuration around the nail root. These nail LRCs express the hair stem cell marker, keratin 15 (K15), and lineage tracing show that these K15-derived cells can contribute to both the nail structure and peri-nail epidermis, and more toward the latter. Thus, this stem cell population is bifunctional. Upon nail plucking injury, the homeostasis is tilted with these SCs dominantly delivering progeny to the nail matrix and differentiated nail plate, demonstrating their plasticity to adapt to wounding stimuli. Moreover, in vivo engraftment experiments established that transplanted nail LRCs can actively participate in functional nail regeneration. Transcriptional profiling of isolated nail LRCs revealed bone morphogenetic protein signaling favors nail differentiation over epidermal fate. Taken together, we have found a previously unidentified ring-configured population of bifunctional SCs, located at the interface between the nail appendage organ and adjacent epidermis, which physiologically display coordinated homeostatic dynamics but are capable of rediverting stem cell flow in response to injury.


Assuntos
Ectoderma/citologia , Casco e Garras/citologia , Regeneração , Células-Tronco/citologia , Cicatrização , Animais , Proteínas Morfogenéticas Ósseas/metabolismo , Diferenciação Celular , Linhagem da Célula , Proliferação de Células , Células Epidérmicas , Proteínas de Fluorescência Verde/metabolismo , Homeostase , Camundongos , Camundongos Knockout , Transdução de Sinais , Transcrição Genética
9.
Exp Cell Res ; 325(2): 96-103, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24530577

RESUMO

The vertebrate ectoderm gives rise to organs that produce mineralized or keratinized substances, including teeth, hair, and claws. Most of these ectodermal derivatives grow continuously throughout the animal׳s life and have active pools of adult stem cells that generate all the necessary cell types. These organs provide powerful systems for understanding the mechanisms that enable stem cells to regenerate or renew ectodermally derived tissues, and remarkable progress in our understanding of these systems has been made in recent years using mouse models. We briefly compare what is known about stem cells and their niches in incisors, hair follicles, and claws, and we examine expression of Gli1 as a potential example of a shared stem cell marker. We summarize some of the features, structures, and functions of the stem cell niches in these ectodermal derivatives; definition of the basic elements of the stem cell niches in these organs will provide guiding principles for identification and characterization of the niche in similar systems.


Assuntos
Ectoderma/citologia , Células Epiteliais/citologia , Cabelo/citologia , Casco e Garras/citologia , Nicho de Células-Tronco , Dente/citologia , Animais , Ectoderma/metabolismo , Células Epiteliais/metabolismo , Cabelo/metabolismo , Casco e Garras/metabolismo , Humanos , Dente/metabolismo
10.
Nature ; 499(7457): 228-32, 2013 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-23760480

RESUMO

The tips of mammalian digits can regenerate after amputation, like those of amphibians. It is unknown why this capacity is limited to the area associated with the nail. Here we show that nail stem cells (NSCs) reside in the proximal nail matrix and that the mechanisms governing NSC differentiation are coupled directly with their ability to orchestrate digit regeneration. Early nail progenitors undergo Wnt-dependent differentiation into the nail. After amputation, this Wnt activation is required for nail regeneration and also for attracting nerves that promote mesenchymal blastema growth, leading to the regeneration of the digit. Amputations proximal to the Wnt-active nail progenitors result in failure to regenerate the nail or digit. Nevertheless, ß-catenin stabilization in the NSC region induced their regeneration. These results establish a link between NSC differentiation and digit regeneration, and suggest that NSCs may have the potential to contribute to the development of novel treatments for amputees.


Assuntos
Extremidades/fisiologia , Casco e Garras/crescimento & desenvolvimento , Regeneração/fisiologia , Proteínas Wnt/metabolismo , Amputação , Animais , Osso e Ossos/citologia , Osso e Ossos/metabolismo , Diferenciação Celular , Células Cultivadas , Epitélio/metabolismo , Extremidades/crescimento & desenvolvimento , Extremidades/inervação , Casco e Garras/citologia , Casco e Garras/metabolismo , Mesoderma/citologia , Mesoderma/metabolismo , Camundongos , Células-Tronco/citologia , Células-Tronco/metabolismo , Via de Sinalização Wnt , beta Catenina/genética , beta Catenina/metabolismo
11.
Am J Vet Res ; 70(5): 669-77, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19405908

RESUMO

OBJECTIVE: To establish an ex vivo model of blood perfusion in the distal portion of isolated equine forelimbs that closely represents the in vivo situation in the laminar tissue of the hoof. SAMPLE POPULATION: 18 forelimbs collected from 9 healthy adult horses following slaughter at a licensed abattoir. PROCEDURES: The distal portion of isolated equine forelimbs from 9 horses were perfused under physiologic conditions over a period of 6, 8, and 10 hours with autologous blood. To determine cell viability in perfused tissues, indicators for metabolism (lactate generation and glucose and oxygen consumption) as well as indicators for cell damage (potassium concentration and lactate dehydrogenase activity) were examined at 1-hour intervals from samples of the perfusate. Weight gain in the forelimb was used to determine the edema index. After perfusion, light and electron microscopic examinations of laminar tissue specimens were performed. RESULTS: During hemoperfusion of the isolated forelimbs, mean +/- SD glucose consumption was 197.4 +/- 65.1 mg/h, lactate generation was 1.84 +/- 0.79 mmol/h, and oxygen consumption was 6.4 x 10(-6) +/- 8.9 x 10(-5) mL.g(-1).min(-1). Neither an efflux of potassium into the perfusate nor a relevant increase of the lactate dehydrogenase activity was detected, indicating low amounts of cellular damage in the perfused tissues. Weight gain of forelimbs was 1.02 +/- 0.95%. Histologic and ultrastructural appearance of the laminar tissue revealed no signs of tissue damage. CONCLUSIONS AND CLINICAL RELEVANCE: Isolated equine limbs were perfused under physiologic conditions over a period of < or = 10 hours without structural damage to the laminar tissue.


Assuntos
Casco e Garras , Cavalos/fisiologia , Perfusão/veterinária , Extremidade Superior , Animais , Gasometria , Sobrevivência Celular , Feminino , Hemodinâmica , Casco e Garras/irrigação sanguínea , Casco e Garras/citologia , Casco e Garras/metabolismo , Cavalos/metabolismo , Masculino , Fatores de Tempo , Extremidade Superior/anatomia & histologia , Extremidade Superior/irrigação sanguínea , Extremidade Superior/fisiologia
12.
J Dairy Sci ; 92(5): 1913-23, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19389949

RESUMO

Delineating the factors that orchestrate keratinocyte growth and differentiation in the claw is pivotal to understanding the quality of hoof horn production in health and disease. The specific objectives of this investigation were to establish an in vitro culture system for bovine coronary region keratinocytes and dermal fibroblasts, determine the colony-forming capacity of epidermal keratinocytes in the coronary region, and characterize transcriptional changes in specific cytokine, growth factor, and receptor genes during colony formation in coculture. Fibroblasts and keratinocytes from the coronary region of the lateral, hind limb claw were collected, and 5.0 x 10(3) and 7.5 x 10(3) keratinocytes were cultured in the presence or absence of fibroblast monolayers, respectively. The 2 densities of keratinocytes formed 144 +/- 15.8 and 183 +/- 26.9 colonies, respectively, in the presence of dermal fibroblasts, whereas no colonies developed in the absence of dermal fibroblasts. Keratinocytes with the ability to show colony formation comprised 1.09% +/- 0.16 to 1.77% +/- 0.28 of the keratinocyte population isolated from the coronary region. Keratinocyte-fibroblast cocultures developed a time-dependent increased expression of several growth factors, cytokines, and receptors. These findings demonstrated that keratinocytes from the bovine coronary region formed colonies in vitro and that colony formation occurred with an absolute dependence on dermal fibroblasts. Colony growth was associated with increased transcriptional expression of cytokine, growth factor, and receptor expression known to drive keratinocyte colony formation in other species. The results indicate that horn-producing keratinocytes must interact with dermal fibroblasts during normal tissue homeostasis in the bovine claw.


Assuntos
Bovinos/crescimento & desenvolvimento , Bovinos/metabolismo , Derme/metabolismo , Epiderme/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Casco e Garras/citologia , Animais , Bovinos/genética , Técnicas de Cocultura , Citocinas/genética , Feminino , Fibroblastos/citologia , Perfilação da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intercelular/genética , Queratinócitos/citologia , Queratinócitos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
Equine Vet J ; 40(5): 473-80, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18487104

RESUMO

REASONS FOR PERFORMING STUDY: Differences in hoof morphology have largely been underappreciated in the literature until recently, and it is these that hold the key to interpreting functional adaptation in the hoof. HYPOTHESES: Primary laminar morphology correlates with hoof capsule shape; and breeds with different hoof shapes and loadings show different patterns of correlation. METHODS: Seventeen measurements of capsule shape and 3 of primary epidermal laminae (PEL) morphology (spacing, orientation and curvature) were made on right and left front hooves from 27 Standardbred and 25 Thoroughbred horses, and tested for breed differences. Three laminar variables (spacing, orientation and curvature) were measured on each hoof for samples of 25 PEL in 5 circumferential and 4 proximodistal locations. Pairwise correlations of capsular and laminar measurements were compared within breeds. Significant correlations were mapped onto the 20 sampling sites. RESULTS: Capsule shape differed significantly between breeds in 7 measurements and in a multivariate test. Between breeds, PEL differed in orientation and spacing primarily at the medial quarters and heels, and in curvature at both quarters (P<0.05). Significant correlations between several pairs of capsule and laminar variables were found at sample locations that differed markedly between breeds. CONCLUSIONS: Laminar morphology, hoof capsule shape and correlations between them differ between Standardbreds and Thoroughbreds. These results support the concept that remodelling of PEL is, at least in part, stimulated and directed by varying stress or strain levels in the laminar junction. POTENTIAL RELEVANCE: Understanding the biological responses of hoof tissues to stress should add to the ability to prevent lameness involving the hoof and maintain its health.


Assuntos
Adaptação Fisiológica , Cruzamento , Ossos do Pé/anatomia & histologia , Casco e Garras/anatomia & histologia , Cavalos/anatomia & histologia , Animais , Fenômenos Biomecânicos , Feminino , Ossos do Pé/fisiologia , Casco e Garras/citologia , Casco e Garras/fisiologia , Cavalos/fisiologia , Masculino , Valores de Referência
15.
Artigo em Inglês | MEDLINE | ID: mdl-17827046

RESUMO

Calpains are Ca2+-dependent proteinases that mediate protein turnover in crustacean skeletal muscles. We used an antibody directed against lobster muscle-specific calpain (Ha-CalpM) to examine its distribution in differentiating juvenile lobster claw muscles. These muscles are comprised of both fast and slow fibers early in development, but become specialized into predominantly fast or exclusively slow muscles in adults. The transition into adult muscle types requires that myofibrillar proteins specific for fast or slow muscles to be selectively removed and replaced by the appropriate proteins. Using immunohistochemistry, we observed a distinct staining pattern where staining was preferentially localized in the fiber periphery along one side of the fiber. Immunolabeling with an antibody directed against synaptotagmin revealed that the calpain staining was greatest in the cytoplasm adjacent to synaptic terminals. In complementary analyses, we used sequence-specific primers with real-time PCR to quantify the levels of Ha-CalpM in whole juvenile claw muscles. These expression levels were not significantly different between cutter and crusher claws, but were positively correlated with the expression of fast myosin heavy chain. The anatomical localization of Ha-CalpM near motor endplates, coupled with the correlation with fast myofibrillar gene expression, suggests a role for this intracellular proteinase in fiber type switching.


Assuntos
Calpaína/metabolismo , Diferenciação Celular , Casco e Garras/metabolismo , Placa Motora/metabolismo , Desenvolvimento Muscular , Músculo Esquelético/metabolismo , Nephropidae/metabolismo , Envelhecimento/metabolismo , Animais , Western Blotting , Calpaína/genética , Diferenciação Celular/genética , Regulação da Expressão Gênica no Desenvolvimento , Casco e Garras/citologia , Casco e Garras/crescimento & desenvolvimento , Imuno-Histoquímica , Placa Motora/citologia , Placa Motora/crescimento & desenvolvimento , Desenvolvimento Muscular/genética , Músculo Esquelético/citologia , Músculo Esquelético/crescimento & desenvolvimento , Cadeias Pesadas de Miosina/metabolismo , Nephropidae/citologia , Nephropidae/genética , Nephropidae/crescimento & desenvolvimento , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sinaptotagminas/metabolismo
16.
Am J Vet Res ; 67(12): 1947-55, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17144792

RESUMO

OBJECTIVE: To evaluate morphologic changes of the stratum internum of hooves from near-term fetal, newborn, and yearling horses. ANIMALS: Feet from 27 near-term equine fetuses, 19 newborn foals, and 8 yearlings. PROCEDURES: Primary epidermal laminae (PEL) of the stratum internum were examined for evidence of architectural changes. RESULTS: In near-term fetuses, the PEL had a homogeneous appearance and symmetric distribution around the hoof wall with no significant differences in PEL density between the toe and quarters. However after birth, branched laminae at the toe formed within the first few weeks, which significantly increased PEL density at the toe, compared with the quarters. In yearlings, morphology of the PEL differed from that in younger foals and the PEL density was significantly greater at the toe than the quarters. The PEL density at the toe and medial and lateral quarters was significantly different from each other, as these PEL densities appeared to have been associated with conformation. No significant differences in PEL densities between forefeet and hind feet were detected in any group. CONCLUSIONS AND CLINICAL RELEVANCE: Findings indicate that the stratum internum of the inner hoof wall undergoes several morphologic changes shortly after birth. The PEL become branched with a greater PEL density at the toe than the quarters. In an asymmetric foot, more PEL were associated with the sloping side than the steep side of the foot. Findings suggested that PEL growth may also occur by bifurcation as well as by mitosis from the coronet and that wall stress may be associated with increased PEL density.


Assuntos
Células Epidérmicas , Epiderme/crescimento & desenvolvimento , Casco e Garras/citologia , Casco e Garras/crescimento & desenvolvimento , Cavalos/anatomia & histologia , Animais , Animais Recém-Nascidos/fisiologia , Epiderme/embriologia , Feto/fisiologia , Casco e Garras/embriologia , Cavalos/embriologia , Cavalos/crescimento & desenvolvimento
18.
Equine Vet J ; 36(3): 236-41, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15147131

RESUMO

REASONS FOR PERFORMING STUDY: Current theories explaining how the hoof wall 'grows' and moves past the stationary distal phalanx are speculative and based on incomplete evidence. Movement in the lamellar region could occur by cell proliferation or an enzyme-based remodelling process. Since laminitis pathogenesis appears to involve increased transcription and activation of enzymes normally involved in tissue remodelling, it is important to know precisely which process dominates the lamellar region of the hoof.. OBJECTIVES: To investigate epidermal cell proliferation in the equine hoof wall and calculate a proliferative index (PI) for the coronet, lamellae and toe. METHODS: An analogue of thymidine, 5-bromo-2'-deoxyuridine (BRdU), was infused i.v. into 5 ponies. After tissue harvesting, BRdU (and therefore basal cell proliferation) was detected immunohistochemically using mouse anti-BRdU. PIs were calculated for the coronet and 10 levels of the dorsal hoof wall lamellae. RESULTS: The highest PIs (mean +/- s.e.) were in the coronet; 12.04% +/- 1.59 and proximal lamellae (7.13% +/- 1.92) and are therefore growth zones of the proximal hoof wall. PIs of more distal lamellae were 0.11% +/- 0.04 to 0.97% +/- 0.29; significantly lower (P = 0.05) than the lamellar growth zone. CONCLUSIONS: A 20-fold PI decrease between proximal and more distal lamellae suggests that the majority of the normal lamellae are nonproliferative and their main function is to suspend the distal phalanx within the hoof capsule. Remodelling within the hoof wall epidermal lamellae, which must occur as the hoof wall moves past the stationary distal phalanx, is a process not requiring epidermal cell proliferation. POTENTIAL RELEVANCE: A hoof lamellar epidermis that remodels using the same MMPs involved in laminitis pathogenesis implies that laminitis is a normal process out of control. Understanding MMP control and how the normal lamellar epidermis achieves this will help in the development of better laminitis preventative and treatment strategies.


Assuntos
Células Epidérmicas , Casco e Garras/citologia , Metaloendopeptidases/metabolismo , Animais , Membrana Basal/citologia , Membrana Basal/crescimento & desenvolvimento , Membrana Basal/metabolismo , Bromodesoxiuridina/administração & dosagem , Divisão Celular , Epiderme/crescimento & desenvolvimento , Epiderme/metabolismo , Feminino , Doenças do Pé/enzimologia , Doenças do Pé/etiologia , Doenças do Pé/patologia , Doenças do Pé/veterinária , Casco e Garras/crescimento & desenvolvimento , Casco e Garras/metabolismo , Doenças dos Cavalos/enzimologia , Doenças dos Cavalos/etiologia , Doenças dos Cavalos/patologia , Cavalos , Imuno-Histoquímica/veterinária , Inflamação/enzimologia , Inflamação/etiologia , Inflamação/patologia , Inflamação/veterinária , Infusões Intravenosas/veterinária , Masculino
19.
Equine Vet J ; 36(3): 242-7, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15147132

RESUMO

REASONS FOR PERFORMING STUDY: The key lesion of laminitis is separation at the hoof lamellar dermal-epidermal interface. For this to happen the structural and adhesion proteins of the basement membrane zone must be altered. Which proteins and how damage to them leads to the lamellar separation of laminitis is unknown. OBJECTIVES: To investigate lamellar hemidesmosome and cytoskeleton damage and basement membrane dysadhesion using light microscopy (LM) and immunofluorescence microscopy (IFM). METHODS: Cryostat sections of lamellar tissues from 2 control and 6 Standardbred horses with oligofructose induced laminitis were studied using LM and IFM. Plectin, integrin alpha6 and BP230 antibody was used to label hemidesmosome intracellular plaque proteins and anti-BP180 and anti-laminin 5 (L5) was used to label anchoring filament (AF) proteins. Cytoskeleton intermediate filaments were labelled using anti-cytokeratin 14. The primary antibodies of selected sections were double labelled to show protein co-localisation. RESULTS: Laminitis caused reduction of transmembrane integrin alpha6, the AF proteins BP180 and L5, and failure of co-localisation of BP180 and L5. Proteins of the inner hemidesmosomal plaque, plectin and BP230, were unaffected. CONCLUSIONS: Loss of co-localisation of L5 and BP180 suggests that, during the acute phase of laminitis, L5 is cleaved and therefore, the AFs connecting the epidermis to the dermis, fail. Without a full complement of AFs separation at the lamellar dermo-epidermal junction occurs. POTENTIAL RELEVANCE: Suppressing or inhibiting metalloproteinase activity may prevent L5 cleavage and therefore the lamellar dermo-epidermal separation of laminitis.


Assuntos
Doenças do Pé/veterinária , Casco e Garras/patologia , Doenças dos Cavalos/patologia , Laminina/fisiologia , Doença Aguda , Animais , Anticorpos/imunologia , Membrana Basal/citologia , Membrana Basal/patologia , Adesão Celular/fisiologia , Citoesqueleto/patologia , Doenças do Pé/patologia , Hemidesmossomos/patologia , Casco e Garras/citologia , Cavalos , Imuno-Histoquímica/veterinária , Inflamação/patologia , Inflamação/veterinária , Laminina/análise , Microscopia de Fluorescência/veterinária
20.
Biomaterials ; 24(28): 5163-71, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14568433

RESUMO

The aim of the present study was to evaluate the capability of novel biodegradable polyurethane scaffolds to support attachment, growth and maintenance of differentiated chondrocytes in vitro for up to 42 days. After an initial decrease, although not significant, the DNA content of the constructs remained constant over the culture time. A progressive increase in glycosaminoglycans and collagen was observed during the culture period. However, a significant release of matrix molecules into the culture medium was also noticeable. At the transcriptional level, a decrease in aggrecan and procollagen II mRNA expression was noticeable, whereas procollagen I expression was increased. To conclude, the present data demonstrate that biodegradable polyurethane porous scaffolds seeded with articular chondrocytes support cell attachment and the production of extracellular matrix proteins. The limitations of the system are the diffusion of large amounts of matrix molecules into the culture medium and the dedifferentiation of the chondrocytes with prolonged time in culture. However, due to the favourable mechanical properties of the polyurethane scaffold, stimulation of chondrocytes by mechanical loading can be considered in order to improve the formation of a functional cartilage-like extracellular matrix.


Assuntos
Implantes Absorvíveis , Materiais Biocompatíveis/química , Cartilagem Articular/citologia , Cartilagem Articular/crescimento & desenvolvimento , Condrócitos/citologia , Condrócitos/fisiologia , Poliuretanos/química , Engenharia Tecidual/métodos , Animais , Bovinos , Adesão Celular/fisiologia , Técnicas de Cultura de Células/instrumentação , Técnicas de Cultura de Células/métodos , Divisão Celular/fisiologia , Sobrevivência Celular/fisiologia , Células Cultivadas , Força Compressiva , Matriz Extracelular/fisiologia , Matriz Extracelular/ultraestrutura , Proteínas da Matriz Extracelular/metabolismo , Casco e Garras/citologia , Casco e Garras/crescimento & desenvolvimento , Teste de Materiais , Porosidade , Engenharia Tecidual/instrumentação
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