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1.
PLoS One ; 15(7): e0235232, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32735618

RESUMO

The tamoxifen-dependent Cre/lox system in transgenic mice has become an important research tool across all scientific disciplines for manipulating gene expression in specific cell types. In these mouse models, Cre-recombination is not induced until tamoxifen is administered, which allows researchers to have temporal control of genetic modifications. Interestingly, tamoxifen has been identified as a potential therapy for spinal cord injury (SCI) and traumatic brain injury patients due to its neuroprotective properties. It is also reparative in that it stimulates oligodendrocyte differentiation and remyelination after toxin-induced demyelination. However, it is unknown whether tamoxifen is neuroprotective and neuroreparative when administration is delayed after SCI. To properly interpret data from transgenic mice in which tamoxifen treatment is delayed after SCI, it is necessary to identify the effects of tamoxifen alone on anatomical and functional recovery. In this study, female and male mice received a moderate mid-thoracic spinal cord contusion. Mice were then gavaged with corn oil or a high dose of tamoxifen from 19-22 days post-injury, and sacrificed 42 days post-injury. All mice underwent behavioral testing for the duration of the study, which revealed that tamoxifen treatment did not impact hindlimb motor recovery. Similarly, histological analyses revealed that tamoxifen had no effect on white matter sparing, total axon number, axon sprouting, glial reactivity, cell proliferation, oligodendrocyte number, or myelination, but tamoxifen did decrease the number of neurons in the dorsal and ventral horn. Semi-thin sections confirmed that axon demyelination and remyelination were unaffected by tamoxifen. Sex-specific responses to tamoxifen were also assessed, and there were no significant differences between female and male mice. These data suggest that delayed tamoxifen administration after SCI does not change functional recovery or improve tissue sparing in female or male mice.


Assuntos
Neurônios/efeitos dos fármacos , Remielinização/efeitos dos fármacos , Traumatismos da Medula Espinal/tratamento farmacológico , Tamoxifeno/administração & dosagem , Tempo para o Tratamento , Administração Oral , Animais , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Membro Posterior/inervação , Membro Posterior/fisiologia , Humanos , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Oligodendroglia/efeitos dos fármacos , Recuperação de Função Fisiológica/efeitos dos fármacos , Fatores Sexuais , Corno Dorsal da Medula Espinal/citologia , Corno Dorsal da Medula Espinal/efeitos dos fármacos , Corno Ventral da Medula Espinal/citologia , Corno Ventral da Medula Espinal/efeitos dos fármacos
2.
PLoS One ; 15(7): e0235847, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645070

RESUMO

Canine hip dysplasia (HD) is a complex developmental disease of the coxo-femoral joint and is one of the most common orthopedic conditions in dogs. Due to the genetic contribution, most of the programs fighting against HD recommend selective breeding that excludes affected dogs. Using the best-scoring dogs for breeding may reduce the prevalence of HD. In France, the phenotypic screening of coxo-femoral joint conformation remains a strategy for breeders to establish selection decisions. The HD prevalence was evaluated in 10 breeds, based on the assessment of 27,710 dogs, during the 1997-2017 screening period, which was divided into 3 homogeneous cohorts for analysis. The global HD prevalence varied widely among breeds from 5% (Siberian Husky) to 51.9% (Cane Corso). It decreased over time in 6 breeds, among which 4 (Cane Corso, Gordon Setter, Rottweiler and White Swiss Shepherd) showed a significant decrease. A statistically significant increase in HD prevalence was noted for the Siberian Husky. Although the efficacy of phenotype-based breeding programs remains controversial, our results are in accordance with several recent studies showing that long-term selection policies are valuable, as they may help decreasing the HD prevalence in some breeds. The complementary use of more recent tools such as estimated breeding values and genomics would probably help breeders achieve more substantive results.


Assuntos
Cães , Displasia Pélvica Canina/epidemiologia , Animais , Cruzamento , Cães/fisiologia , França/epidemiologia , Membro Posterior/diagnóstico por imagem , Displasia Pélvica Canina/diagnóstico por imagem , Programas de Rastreamento/veterinária , Prevalência , Radiografia , Estudos Retrospectivos , Seleção Artificial
3.
Proc Natl Acad Sci U S A ; 117(32): 19033-19044, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32709748

RESUMO

Therapeutic factors secreted by mesenchymal stem cells (MSCs) promote angiogenesis in vivo. However, delivery of MSCs in the absence of a cytoprotective environment offers limited efficacy due to low cell retention, poor graft survival, and the nonmaintenance of a physiologically relevant dose of growth factors at the injury site. The delivery of stem cells on an extracellular matrix (ECM)-based platform alters cell behavior, including migration, proliferation, and paracrine activity, which are essential for angiogenesis. We demonstrate the biophysical and biochemical effects of preconditioning human MSCs (hMSCs) for 96 h on a three-dimensional (3D) ECM-based microgel platform. By altering the macromolecular concentration surrounding cells in the microgels, the proangiogenic phenotype of hMSCs can be tuned in a controlled manner through cell-driven changes in extracellular stiffness and "outside-in" integrin signaling. The softest microgels were tested at a low cell dose (5 × 104 cells) in a preclinical hindlimb ischemia model showing accelerated formation of new blood vessels with a reduced inflammatory response impeding progression of tissue damage. Molecular analysis revealed that several key mediators of angiogenesis were up-regulated in the low-cell-dose microgel group, providing a mechanistic insight of pathways modulated in vivo. Our research adds to current knowledge in cell-encapsulation strategies by highlighting the importance of preconditioning or priming the capacity of biomaterials through cell-material interactions. Obtaining therapeutic efficacy at a low cell dose in the microgel platform is a promising clinical route that would aid faster tissue repair and reperfusion in "no-option" patients suffering from peripheral arterial diseases, such as critical limb ischemia (CLI).


Assuntos
Células-Tronco Mesenquimais/química , Células-Tronco Mesenquimais/citologia , Microgéis/química , Neovascularização Fisiológica , Animais , Proliferação de Células , Células Imobilizadas/química , Células Imobilizadas/citologia , Células Imobilizadas/metabolismo , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Membro Posterior/irrigação sanguínea , Membro Posterior/metabolismo , Membro Posterior/cirurgia , Humanos , Integrinas/genética , Integrinas/metabolismo , Isquemia/fisiopatologia , Isquemia/cirurgia , Isquemia/terapia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Nus
4.
Nat Commun ; 11(1): 3102, 2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32555157

RESUMO

Real-time monitoring of vessel dysfunction is of great significance in preclinical research. Optical bioimaging in the second near-infrared (NIR-II) window provides advantages including high resolution and fast feedback. However, the reported molecular dyes are hampered by limited blood circulation time (~ 5-60 min) and short absorption and emission wavelength, which impede the accurate long-term monitoring. Here, we report a NIR-II molecule (LZ-1105) with absorption and emission beyond 1000 nm. Thanks to the long blood circulation time (half-life of 3.2 h), the fluorophore is used for continuous real-time monitoring of dynamic vascular processes, including ischemic reperfusion in hindlimbs, thrombolysis in carotid artery and opening and recovery of the blood brain barrier (BBB). LZ-1105 provides an approach for researchers to assess vessel dysfunction due to the long excitation and emission wavelength and long-term blood circulation properties.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Corantes Fluorescentes , Membro Posterior/diagnóstico por imagem , Traumatismo por Reperfusão/diagnóstico por imagem , Trombose/diagnóstico por imagem , Doenças Vasculares/diagnóstico por imagem , Animais , Feminino , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos Nus
5.
PLoS One ; 15(6): e0233266, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32492034

RESUMO

For gait classification, hoof-on and hoof-off events are fundamental locomotion characteristics of interest. These events can be measured with inertial measurement units (IMUs) which measure the acceleration and angular velocity in three directions. The aim of this study was to present two algorithms for automatic detection of hoof-events from the acceleration and angular velocity signals measured by hoof-mounted IMUs in walk and trot on a hard surface. Seven Warmblood horses were equipped with two wireless IMUs, which were attached to the lateral wall of the right front (RF) and hind (RH) hooves. Horses were walked and trotted on a lead over a force plate for internal validation. The agreement between the algorithms for the acceleration and angular velocity signals with the force plate was evaluated by Bland Altman analysis and linear mixed model analysis. These analyses were performed for both hoof-on and hoof-off detection and for both algorithms separately. For the hoof-on detection, the angular velocity algorithm was the most accurate with an accuracy between 2.39 and 12.22 ms and a precision of around 13.80 ms, depending on gait and hoof. For hoof-off detection, the acceleration algorithm was the most accurate with an accuracy of 3.20 ms and precision of 6.39 ms, independent of gait and hoof. These algorithms look highly promising for gait classification purposes although the applicability of these algorithms should be investigated under different circumstances, such as different surfaces and different hoof trimming conditions.


Assuntos
Algoritmos , Análise da Marcha/veterinária , Marcha/fisiologia , Cavalos/fisiologia , Aceleração , Animais , Fenômenos Biomecânicos , Feminino , Membro Anterior/fisiologia , Análise da Marcha/instrumentação , Análise da Marcha/estatística & dados numéricos , Membro Posterior/fisiologia , Casco e Garras/fisiologia , Modelos Lineares , Masculino , Tecnologia de Sensoriamento Remoto/instrumentação , Tecnologia de Sensoriamento Remoto/estatística & dados numéricos , Tecnologia de Sensoriamento Remoto/veterinária , Corrida/fisiologia , Caminhada/fisiologia , Tecnologia sem Fio/instrumentação , Tecnologia sem Fio/estatística & dados numéricos
6.
PLoS One ; 15(6): e0235266, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32589662

RESUMO

BACKGROUND: Chronic rejection remains the Achilles heel in vascularized composite allotransplantation. Animal models to specifically study chronic rejection in vascularized composite allotransplantation do not exist so far. However, there are established rat models to study chronic rejection in solid organ transplantation such as allogeneic transplantation between the rat strains Lewis and Fischer344. Thus, we initiated this study to investigate the applicability of hindlimb transplantation between these strains to imitate chronic rejection in vascularized composite allotransplantation and identify potential markers. METHODS: Allogeneic hindlimb transplantation were performed between Lewis (recipient) and Fischer344 (donor) rats with either constant immunosuppression or a high dose immunosuppressive bolus only in case of acute skin rejections. Histology, immunohistochemistry, microarray and qPCR analysis were used to detect changes in skin and muscle at postoperative day 100. RESULTS: We were able to demonstrate significant intimal proliferation, infiltration of CD68 and CD4 positive cells, up-regulation of inflammatory cytokines and initiation of muscular fibrosis in the chronic rejection group. Microarray analysis and subsequent qPCR identified CXC ligands 9-11 as potential markers of chronic rejection. CONCLUSIONS: The Fischer344 to Lewis hindlimb transplantation model may represent a new option to study chronic rejection in vascularized composite allotransplantation in an experimental setting. CXC ligands 9-11 deserve further research to investigate their role as chronic rejection markers.


Assuntos
Rejeição de Enxerto/etiologia , Rejeição de Enxerto/metabolismo , Alotransplante de Tecidos Compostos Vascularizados/efeitos adversos , Animais , Biomarcadores/metabolismo , Doença Crônica , Modelos Animais de Doenças , Fibrose , Regulação da Expressão Gênica , Rejeição de Enxerto/patologia , Membro Posterior/patologia , Ratos , Pele/patologia
7.
PLoS One ; 15(6): e0235362, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32584895

RESUMO

OBJECTIVE: Cardiovascular disease is a leading cause of death worldwide. Obesity-related metabolic disorders including dyslipidemia cause impaired collateralization under ischemic conditions, thereby resulting in exacerbated cardiovascular dysfunction. Pemafibrate is a novel selective PPARα modulator, which has been reported to improve atherogenic dyslipidemia, in particular, hypertriglyceridemia and low HDL-cholesterol. Here, we investigated whether pemafibrate modulates the revascularization process in a mouse model of hindlimb ischemia. METHODS AND RESULTS: Male wild-type (WT) mice were randomly assigned to two groups, normal diet or pemafibrate admixture diet from the ages of 6 weeks. After 4 weeks, mice were subjected to unilateral hindlimb surgery to remove the left femoral artery and vein. Pemafibrate treatment enhanced blood flow recovery and capillary formation in ischemic limbs of mice, which was accompanied by enhanced phosphorylation of endothelial nitric oxide synthase (eNOS). Treatment of cultured endothelial cells with pemafibrate resulted in increased network formation and migratory activity, which were blocked by pretreatment with the NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME). Pemafibrate treatment also increased plasma levels of the PPARα-regulated gene, fibroblast growth factor (FGF) 21 in WT mice. Systemic administration of adenoviral vectors expressing FGF21 (Ad-FGF21) to WT mice enhanced blood flow recovery, capillary density and eNOS phosphorylation in ischemic limbs. Treatment of cultured endothelial cells with FGF21 protein led to increases in endothelial cell network formation and migration, which were canceled by pretreatment with L-NAME. Furthermore, administration of pemafibrate or Ad-FGF21 had no effects on blood flow in ischemic limbs in eNOS-deficient mice. CONCLUSION: These data suggest that pemafibrate can promote revascularization in response to ischemia, at least in part, through direct and FGF21-mediated modulation of endothelial cell function. Thus, pemafibrate could be a potentially beneficial drug for ischemic vascular disease.


Assuntos
Benzoxazóis/farmacologia , Butiratos/farmacologia , Isquemia/patologia , Neovascularização Fisiológica/efeitos dos fármacos , Óxido Nítrico Sintase Tipo III/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Fatores de Crescimento de Fibroblastos/sangue , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Membro Posterior/irrigação sanguínea , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Camundongos , Camundongos Knockout , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase Tipo III/antagonistas & inibidores , PPAR alfa/química , PPAR alfa/metabolismo , Fosforilação/efeitos dos fármacos
8.
J Vasc Res ; 57(4): 185-194, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32526735

RESUMO

Information on the function of transient receptor potential vanilloid 1 (TRPV1) in arteriogenesis is limited. We aimed to verify whether TRPV1 is involved in collateral vessel growth in rat hind limbs and elucidate the possible subcellular action mechanisms. Adult Sprague Dawley rats were chosen to establish the hind limb ischemic model and treatment with capsaicin. Angiographies were performed, and tissue was isolated for immunohistochemistry. In vitro, rat aortic endothelial cells (RAECs) were treated with capsaicin and antagonist capsazepine. The RAEC proliferation was determined, and the protein and mRNA levels of Ca2+-dependent transcription factors were assessed. In vivo, the collateral vessels exhibited positive outward remodeling characterized by enhanced inflammatory cell/macrophage accumulation in the adventitia and activated cell proliferation in all layers of the vascular wall and elevated endothelial NO synthetase expression in the rats with hind limb ligation. In RAECs, TRPV1 activation-induced Ca2+-dependent transcriptional factors, nuclear factor of activated T cells 1, calsenilin and myocyte enhancer factor 2C increase, and augmented RAEC proliferation could be a subcellular mechanism for TRPV1 in endothelial cells and ultimately contribute to collateral vessel growth. TRPV1, a novel candidate, positively regulates arteriogenesis, meriting further studies to unravel the potential therapeutic target leading to improved collateral vessel growth for treating ischemic diseases.


Assuntos
Indutores da Angiogênese/farmacologia , Artérias/efeitos dos fármacos , Capsaicina/farmacologia , Circulação Colateral/efeitos dos fármacos , Isquemia/tratamento farmacológico , Músculo Esquelético/irrigação sanguínea , Neovascularização Fisiológica/efeitos dos fármacos , Canais de Cátion TRPV/agonistas , Animais , Artérias/metabolismo , Artérias/fisiopatologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Membro Posterior , Isquemia/metabolismo , Isquemia/fisiopatologia , Proteínas Interatuantes com Canais de Kv/metabolismo , Fatores de Transcrição MEF2/metabolismo , Fatores de Transcrição NFATC/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Ratos Sprague-Dawley , Fluxo Sanguíneo Regional , Transdução de Sinais , Canais de Cátion TRPV/metabolismo
9.
Acta Chir Orthop Traumatol Cech ; 87(2): 90-94, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32396508

RESUMO

INTRODUCTION Vitamin D-deficiency is known to cause nerve conduction impairments, cancer and chronic diseases, as well as the pathogenesis of osteoarthritis. Our goal with this study is to evaluate the cartilage healing by applying intraarticular 1α, 25 (OH) 2D3 at different doses in rats with normal vitamin D levels and metabolism, which we made focal chondral damage model in the knee joint. MATERIAL AND METHODS 35 male Sprague-Dawley rats aged 20-24 weeks were used in our study. Both knees of rats were cartilage defected surgically on day 0. Joint injections performed at 06:00 am on 0th and 2nd days and after second injection others performed on days 9-16 and 23 following a weekly period. RESULTS In the fourth week, hematoxylin eosin staining measurements showed statistically significant difference according to the groups (p < 0.01) Metalloproteinase-13 (MMP-13) in histological staining for evaluating cartilage healing and healing levels showed statistically significant differences between the groups at first week and fourth week (p < 0.05). DISCUSSION Vitamin D, which affects many tissues through its receptors, is believed to be chondroprotective and neuroprotective by decreasing the expression of MMP in cartilage fibroblast, macrophage, lymphocyte through its intracellular receptors. To the best of our knowledge, this is the first study known to be intraarticular use of 1α, 25-dihydroxyvitamin D3. Our study has been found to be safe and successful in terms of weight, systemic PTH and 1α, 25-dihydroxyvitamin D3 levels in rats during treatment as well as better healing of cartilage damage. Key words: vitamin D3 receptor, articular cartilage, orthopedics, nerve conduction.


Assuntos
Calcitriol/administração & dosagem , Cartilagem Articular/efeitos dos fármacos , Membro Posterior/lesões , Inibidores de Metaloproteinases de Matriz/administração & dosagem , Cicatrização/efeitos dos fármacos , Animais , Cartilagem Articular/lesões , Modelos Animais de Doenças , Injeções Intra-Articulares , Masculino , Metaloproteinase 13 da Matriz/metabolismo , Ratos , Ratos Sprague-Dawley
10.
Nat Commun ; 11(1): 2289, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32385263

RESUMO

The osteoblast differentiation capacity of skeletal stem cells (SSCs) must be tightly regulated, as inadequate bone formation results in low bone mass and skeletal fragility, and over-exuberant osteogenesis results in heterotopic ossification (HO) of soft tissues. RUNX2 is essential for tuning this balance, but the mechanisms of posttranslational control of RUNX2 remain to be fully elucidated. Here, we identify that a CK2/HAUSP pathway is a key regulator of RUNX2 stability, as Casein kinase 2 (CK2) phosphorylates RUNX2, recruiting the deubiquitinase herpesvirus-associated ubiquitin-specific protease (HAUSP), which stabilizes RUNX2 by diverting it away from ubiquitin-dependent proteasomal degradation. This pathway is important for both the commitment of SSCs to osteoprogenitors and their subsequent maturation. This CK2/HAUSP/RUNX2 pathway is also necessary for HO, as its inhibition blocked HO in multiple models. Collectively, active deubiquitination of RUNX2 is required for bone formation and this CK2/HAUSP deubiquitination pathway offers therapeutic opportunities for disorders of inappropriate mineralization.


Assuntos
Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Ossificação Heterotópica/metabolismo , Osteogênese , Adulto , Idoso , Animais , Caseína Quinase II/genética , Caseína Quinase II/metabolismo , Diferenciação Celular , Displasia Cleidocraniana/genética , Displasia Cleidocraniana/patologia , Feminino , Deleção de Genes , Haploinsuficiência/genética , Membro Posterior/metabolismo , Humanos , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Ossificação Heterotópica/genética , Ossificação Heterotópica/patologia , Osteoblastos/metabolismo , Fosforilação , Estabilidade Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Peptidase 7 Específica de Ubiquitina/metabolismo
11.
J Dairy Sci ; 103(7): 6522-6532, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32389472

RESUMO

The high prevalence of claw lesions in dairy cows necessitates the investigation and hopefully elimination of factors involved in the etiology and pathogenesis of these disorders. Indirect genetic selection for specific conformation traits in feet and legs has been evaluated as a means of improving claw health but to date has not been successful. Claw disorders are commonly discussed in context with unequal claw load, and thus this study was designed to investigate the relationship between hind limb conformation and the load exerted on the respective claws. A total of 36 cows were divided into 3 groups of 12 based on the presence of parallel, straight, and cow-hocked hind limb conformation. The vertical ground reaction forces, claw prints, and mean and maximum pressures under the claws were measured in these cows before and after claw trimming. The principal characteristic of all 3 conformation traits was a significantly higher load on the lateral claws compared with the medial claws, which was least severe in cow-hocked cows. After functional foot trimming, the claws of the cows with straight conformation tended to have the most pronounced disproportion between the loads of the paired claws. Considering that a significantly higher load on the lateral claws occurred with all 3 conformations, the potential for improvement of claw health by means of indirect genetic selection for specific hind limb traits appears limited.


Assuntos
Bovinos/fisiologia , Animais , Bovinos/anatomia & histologia , Indústria de Laticínios , Feminino , Membro Posterior/anatomia & histologia , Membro Posterior/fisiologia , Casco e Garras/anatomia & histologia , Casco e Garras/fisiologia , Pressão , Tarso Animal/anatomia & histologia , Tarso Animal/fisiologia , Suporte de Carga
12.
PLoS One ; 15(4): e0231904, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32320449

RESUMO

Detection of lameness in cats can be very time-consuming and frustrating. Feline studies have shown that the success of treatment can be evaluated by measurement of the ground reaction force (GRF). However, the possibility of multiple limb involvement or the presence of a compensatory mechanism has not been investigated. Furthermore, there has been no research in cats on possible differences in GRFs between those with stifle problems and those with hip problems, as reported in dogs. In this study, we compared temporospatial parameters and GRFs in 20 lame cats after femoral head and neck ostectomy (FHO) or stifle disease to those in 15 healthy cats. An orthopedic examination was performed in all cats and radiographs were obtained to confirm the disease. GRFs, including peak vertical force (PFz), vertical impulse (IFz), time to PFz, and temporospatial parameters, including step length, paw contact area, and stance phase duration, were calculated. We also calculated the symmetry index (SI) in the forelimbs and hind limbs. The GRFs were normalized to total force (% TF). We found that the IFz (% TF) and PFz (% TF) were lower in the affected limb than in the other limbs in the lame cats. When the lame cats were compared with the sound cats, this difference was only significant for IFz (% TF). The SI values for the PFz and IFz were significantly higher in the hind limbs than in the forelimbs in the lame cats group but there was no difference in the SI according to whether the problem was in the hip or stifle. There were also differences in stance phase duration and paw contact area in both the forelimbs and hind limbs between the sound group and the lame group. There was no difference in PFZ (% TF) or IFZ (% TF) in the affected limb between the lame cats with stifle and those after FHO; however, there were changes in time to PFz and step length. In conclusion, mild to moderate lameness can be detected and measured in cats using pressure plates. The compensatory mechanisms in cats at a walk appear to involve shifting the weight to the other three legs without favoring either the contralateral or the diagonal limb.


Assuntos
Membro Posterior , Coxeadura Animal/diagnóstico , Pressão , Animais , Fenômenos Biomecânicos , Gatos , Feminino , Membro Posterior/patologia , Membro Posterior/fisiopatologia , Articulações/patologia , Articulações/fisiopatologia , Coxeadura Animal/patologia , Coxeadura Animal/fisiopatologia , Masculino
13.
J Neurosci ; 40(20): 3882-3895, 2020 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-32291327

RESUMO

Neonatal tissue damage induces long-term deficits in inhibitory synaptic transmission within the spinal superficial dorsal horn (SDH) that include a reduction in primary afferent-evoked, feedforward inhibition onto adult projection neurons. However, the subpopulations of mature GABAergic interneurons which are compromised by early-life injury have yet to be identified. The present research illuminates the persistent effects of neonatal surgical injury on the function of inhibitory SDH interneurons derived from the prodynorphin (DYN) lineage, a population that synapses directly onto lamina I spinoparabrachial neurons and is known to suppress mechanical pain and itch in adults. The results demonstrate that hindpaw incision at postnatal day 3 (P3) significantly decreased the strength of primary afferent-evoked glutamatergic drive onto DYN neurons within the adult mouse SDH while increasing the appearance of afferent-evoked inhibition onto the same population. Neonatal injury also dampened the intrinsic membrane excitability of mature DYN neurons, and reduced their action potential discharge in response to sensory input, compared with naive littermate controls. Furthermore, P3 incision decreased the efficacy of inhibitory DYN synapses onto adult spinoparabrachial neurons, which reflected a prolonged reduction in the probability of GABA release. Collectively, the data suggest that early-life tissue damage may persistently constrain the ability of spinal DYN interneurons to limit ascending nociceptive transmission to the adult brain. This is predicted to contribute to the loss of feedforward inhibition onto mature projection neurons, and the "priming" of nociceptive circuits in the developing spinal cord, following injuries during the neonatal period.SIGNIFICANCE STATEMENT Neonatal injury has lasting effects on pain processing in the adult CNS, including a reduction in feedforward inhibition onto ascending projection neurons in the spinal dorsal horn. While it is clear that spinal GABAergic interneurons are comprised of multiple subpopulations that play distinct roles in somatosensation, the identity of those interneurons which are compromised by tissue damage during early life remains unknown. Here we document persistent deficits in spinal inhibitory circuits involving dynorphin-lineage interneurons previously implicated in gating mechanical pain and itch. Notably, neonatal injury reduced the strength of dynorphin-lineage inhibitory synapses onto mature lamina I spinoparabrachial neurons, a major output of the spinal nociceptive network, which could contribute to the priming of pain pathways by early tissue damage.


Assuntos
Dinorfinas , Membro Posterior/lesões , Inibição Neural , Vias Neurais/fisiopatologia , Corno Dorsal da Medula Espinal/lesões , Potenciais de Ação , Animais , Animais Recém-Nascidos , Análise por Conglomerados , Feminino , Glutamatos/fisiologia , Membro Posterior/inervação , Membro Posterior/fisiopatologia , Interneurônios , Camundongos , Neurônios Aferentes , Nociceptividade , Técnicas de Patch-Clamp , Medula Espinal/fisiopatologia , Corno Dorsal da Medula Espinal/fisiopatologia
14.
Am J Physiol Regul Integr Comp Physiol ; 319(1): R1-R10, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32348680

RESUMO

Dynamic exercise elicits robust increases in sympathetic activity in part due to muscle metaboreflex activation (MMA), a pressor response triggered by activation of skeletal muscle afferents. MMA during dynamic exercise increases arterial pressure by increasing cardiac output via increases in heart rate, ventricular contractility, and central blood volume mobilization. In heart failure, ventricular function is compromised, and MMA elicits peripheral vasoconstriction. Ventricular-vascular coupling reflects the efficiency of energy transfer from the left ventricle to the systemic circulation and is calculated as the ratio of effective arterial elastance (Ea) to left ventricular maximal elastance (Emax). The effect of MMA on Ea in normal subjects is unknown. Furthermore, whether muscle metaboreflex control of Ea is altered in heart failure has not been investigated. We utilized two previously published methods of evaluating Ea [end-systolic pressure/stroke volume (EaPV)] and [heart rate × vascular resistance (EaZ)] during rest, mild treadmill exercise, and MMA (induced via partial reductions in hindlimb blood flow imposed during exercise) in chronically instrumented conscious canines before and after induction of heart failure via rapid ventricular pacing. In healthy animals, MMA elicits significant increases in effective arterial elastance and stroke work that likely maintains ventricular-vascular coupling. In heart failure, Ea is high, and MMA-induced increases are exaggerated, which further exacerbates the already uncoupled ventricular-vascular relationship, which likely contributes to the impaired ability to raise stroke work and cardiac output during exercise in heart failure.


Assuntos
Artérias/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Músculo Esquelético/metabolismo , Condicionamento Físico Animal , Animais , Artérias/inervação , Cães , Elasticidade , Feminino , Frequência Cardíaca , Membro Posterior/irrigação sanguínea , Masculino , Músculo Esquelético/inervação , Neurônios Aferentes , Reflexo/fisiologia , Volume Sistólico , Resistência Vascular
15.
Diab Vasc Dis Res ; 17(3): 1479164120907971, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32223319

RESUMO

OBJECTIVE: Diabetes mellitus is a significant risk factor for peripheral artery disease. Diabetes mellitus induces chronic states of oxidative stress and vascular inflammation that increase neutrophil activation and release of myeloperoxidase. The goal of this study is to determine whether inhibiting myeloperoxidase reduces oxidative stress and neutrophil infiltration, increases vascularization, and improves blood flow in a diabetic murine model of hindlimb ischaemia. METHODS: Leptin receptor-deficient (db/db) mice were subjected to hindlimb ischaemia. Ischaemic mice were treated with N-acetyl-lysyltyrosylcysteine-amide (KYC) to inhibit myeloperoxidase. After ligating the femoral artery, effects of treatments were determined with respect to hindlimb blood flow, neutrophil infiltration, oxidative damage, and the capability of hindlimb extracellular matrix to support human endothelial cell proliferation and migration. RESULTS: KYC treatment improved hindlimb blood flow at 7 and 14 days in db/db mice; decreased the formation of advanced glycation end products, 4-hydroxynonenal, and 3-chlorotyrosine; reduced neutrophil infiltration into the hindlimbs; and improved the ability of hindlimb extracellular matrix from db/db mice to support endothelial cell proliferation and migration. CONCLUSION: These results demonstrate that inhibiting myeloperoxidase reduces oxidative stress in ischaemic hindlimbs of db/db mice, which improves blood flow and reduces neutrophil infiltration such that hindlimb extracellular matrix from db/db mice supports endothelial cell proliferation and migration.


Assuntos
Indutores da Angiogênese/farmacologia , Diabetes Mellitus/metabolismo , Inibidores Enzimáticos/farmacologia , Isquemia/tratamento farmacológico , Músculo Esquelético/irrigação sanguínea , Neovascularização Fisiológica/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Oligopeptídeos/farmacologia , Peroxidase/antagonistas & inibidores , Animais , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Diabetes Mellitus/genética , Diabetes Mellitus/fisiopatologia , Modelos Animais de Doenças , Matriz Extracelular/metabolismo , Membro Posterior , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Isquemia/enzimologia , Isquemia/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infiltração de Neutrófilos/efeitos dos fármacos , Neutrófilos/enzimologia , Estresse Oxidativo/efeitos dos fármacos , Peroxidase/metabolismo , Receptores para Leptina/deficiência , Receptores para Leptina/genética , Fluxo Sanguíneo Regional , Transdução de Sinais
16.
Artigo em Inglês | MEDLINE | ID: mdl-32233950

RESUMO

Homeobox A9 (HOXA9), the expression of which is promoted by mixed lineage leukemia 1 (MLL1) and WD-40 repeat protein 5 (WDR5), is a homeodomain-containing transcription factor that plays an essential role in regulating stem cell activity. HOXA9 has been found to inhibit skeletal muscle regeneration and delay recovery after muscle wounding in aged mice, but little is known about its role in denervated/reinnervated muscles. We performed detailed time-dependent expression analyses of HOXA9 and its promoters, MLL1 and WDR5, in rat gastrocnemius muscles after the following three types of sciatic nerve surgeries: nerve transection (denervation), end-to-end repair (repair), and sham operation (sham). Then, the specific mechanisms of HOXA9 were detected in vitro by transfecting primary satellite cells with empty pIRES2-DsRed2, pIRES2-DsRed2-HOXA9, empty pPLK/GFP-Puro, and pPLK/GFP-Puro-HOXA9 small hairpin RNA (shRNA) plasmids. We found, for the first time, that HOXA9 protein expression simultaneously increased with increasing denervated muscle atrophy severity and that upregulated MLL1 and WDR5 expression was partly associated with denervation. Indeed, in vitro experiments revealed that HOXA9 inhibited myogenic differentiation, affected the best known atrophic signaling pathways, and promoted apoptosis but did not eliminate the differentiation potential of primary satellite cells. HOXA9 may promote denervated muscle atrophy by regulating the activity of satellite cells.


Assuntos
Proteínas de Homeodomínio/metabolismo , Desenvolvimento Muscular , Músculo Esquelético/inervação , Atrofia Muscular/metabolismo , Regeneração Nervosa , Células Satélites de Músculo Esquelético/metabolismo , Nervo Isquiático/cirurgia , Animais , Animais Recém-Nascidos , Apoptose , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Modelos Animais de Doenças , Regulação da Expressão Gênica , Membro Posterior , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Proteínas de Homeodomínio/genética , Masculino , Denervação Muscular , Atrofia Muscular/genética , Atrofia Muscular/patologia , Atrofia Muscular/fisiopatologia , Proteína de Leucina Linfoide-Mieloide/genética , Proteína de Leucina Linfoide-Mieloide/metabolismo , Ratos Sprague-Dawley , Células Satélites de Músculo Esquelético/patologia , Nervo Isquiático/metabolismo , Nervo Isquiático/patologia , Transdução de Sinais , Fatores de Tempo
17.
Proc Natl Acad Sci U S A ; 117(14): 8135-8142, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32205442

RESUMO

Many studies have demonstrated covariation between muscle activations during behavior, suggesting that muscles are not controlled independently. According to one common proposal, this covariation reflects simplification of task performance by the nervous system so that muscles with similar contributions to task variables are controlled together. Alternatively, this covariation might reflect regulation of low-level aspects of movements that are common across tasks, such as stresses within joints. We examined these issues by analyzing covariation patterns in quadriceps muscle activity during locomotion in rats. The three monoarticular quadriceps muscles (vastus medialis [VM], vastus lateralis [VL], and vastus intermedius [VI]) produce knee extension and so have identical contributions to task performance; the biarticular rectus femoris (RF) produces an additional hip flexion. Consistent with the proposal that muscle covariation is related to similarity of muscle actions on task variables, we found that the covariation between VM and VL was stronger than their covariations with RF. However, covariation between VM and VL was also stronger than their covariations with VI. Since all vastii have identical actions on task variables, this finding suggests that covariation between muscle activity is not solely driven by simplification of overt task performance. Instead, the preferentially strong covariation between VM and VL is consistent with the control of internal joint stresses: Since VM and VL produce opposing mediolateral forces on the patella, the high positive correlation between their activation minimizes the net mediolateral patellar force. These results provide important insights into the interpretation of muscle covariations and their role in movement control.


Assuntos
Contração Isométrica/fisiologia , Articulações/fisiologia , Modelos Neurológicos , Movimento/fisiologia , Músculo Quadríceps/inervação , Animais , Fenômenos Biomecânicos , Eletrodos Implantados , Eletromiografia/instrumentação , Feminino , Membro Posterior/inervação , Membro Posterior/fisiologia , Modelos Lineares , Músculo Quadríceps/fisiologia , Ratos
18.
Ann Rheum Dis ; 79(4): 481-489, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32094158

RESUMO

OBJECTIVE: Syndecan-4 (sdc4) is a cell-anchored proteoglycan that consists of a transmembrane core protein and glucosaminoglycan (GAG) side chains. Binding of soluble factors to the GAG chains of sdc4 may result in the dimerisation of sdc4 and the initiation of downstream signalling cascades. However, the question of how sdc4 dimerisation and signalling affects the response of cells to inflammatory stimuli is unknown. METHODS: Sdc4 immunostaining was performed on rheumatoid arthritis (RA) tissue sections. Interleukin (IL)-1 induced extracellular signal-regulated kinases (ERK) phosphorylation and matrix metalloproteinase-3 production was investigated. Il-1 binding to sdc4 was investigated using immunoprecipitation. IL-1 receptor (IL1R1) staining on wild-type, sdc4 and IL1R1 knockout fibroblasts was performed in fluorescence-activated cell sorting analyses. A blocking sdc4 antibody was used to investigate sdc4 dimerisation, IL1R1 expression and the histological paw destruction in the human tumour necrosis factor-alpha transgenic mouse. RESULTS: We show that in fibroblasts, the loss of sdc4 or the antibody-mediated inhibition of sdc4 dimerisation reduces the cell surface expression of the IL-1R and regulates the sensitivity of fibroblasts to IL-1. We demonstrate that IL-1 directly binds to sdc4 and in an IL-1R-independent manner leads to its dimerisation. IL-1-induced dimerisation of sdc4 regulates caveolin vesicle-mediated trafficking of the IL1R1, which in turn determines the responsiveness to IL-1. Administration of antibodies (Ab) against the dimerisation domain of sdc4, thus, strongly reduces the expression IL1R1 on arthritic fibroblasts both in vitro and an animal model of human RA. CONCLUSION: Collectively, our data suggest that Ab that specifically inhibit sdc4 dimerisation may support anti-IL-1 strategies in diseases such as inflammatory arthritis.


Assuntos
Anticorpos Bloqueadores/farmacologia , Artrite Reumatoide/metabolismo , Receptores Tipo I de Interleucina-1/efeitos dos fármacos , Sindecana-4/antagonistas & inibidores , Animais , Artrite Reumatoide/genética , Artrite Reumatoide/patologia , Dimerização , Modelos Animais de Doenças , MAP Quinases Reguladas por Sinal Extracelular/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fibroblastos/metabolismo , Técnicas de Inativação de Genes , Heparitina Sulfato , Membro Posterior , Humanos , Interleucina-1/metabolismo , Interleucina-1beta/metabolismo , Sistema de Sinalização das MAP Quinases , Metaloproteinase 3 da Matriz/metabolismo , Camundongos , Camundongos Transgênicos , Células NIH 3T3 , Osteoartrite/genética , Osteoartrite/metabolismo , Osteoartrite/patologia , Fosforilação/efeitos dos fármacos , Transporte Proteico , Receptores Tipo I de Interleucina-1/metabolismo , Transdução de Sinais , Sindecana-4/genética , Sindecana-4/metabolismo , Membrana Sinovial/metabolismo , Fator de Necrose Tumoral alfa/genética
19.
Nat Commun ; 11(1): 615, 2020 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-32001693

RESUMO

Angiogenesis induction into damaged sites has long been an unresolved issue. Local treatment with pro-angiogenic molecules has been the most common approach. However, this approach has critical side effects including inflammatory coupling, tumorous vascular activation, and off-target circulation. Here, the concept that a structure can guide desirable biological function is applied to physically engineer three-dimensional channel networks in implant sites, without any therapeutic treatment. Microchannel networks are generated in a gelatin hydrogel to overcome the diffusion limit of nutrients and oxygen three-dimensionally. Hydrogel implantation in mouse and porcine models of hindlimb ischemia rescues severely damaged tissues by the ingrowth of neighboring host vessels with microchannel perfusion. This effect is guided by microchannel size-specific regenerative macrophage polarization with the consequent functional recovery of endothelial cells. Multiple-site implantation reveals hypoxia and neighboring vessels as major causative factors of the beneficial function. This technique may contribute to the development of therapeutics for hypoxia/inflammatory-related diseases.


Assuntos
Indutores da Angiogênese/efeitos adversos , Gelatina/química , Gelatina/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Isquemia/terapia , Animais , Modelos Animais de Doenças , Células Endoteliais/patologia , Desenho de Equipamento , Feminino , Membro Posterior/irrigação sanguínea , Membro Posterior/diagnóstico por imagem , Membro Posterior/patologia , Hidrogéis/uso terapêutico , Hipóxia , Isquemia/diagnóstico por imagem , Isquemia/patologia , Macrófagos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Neovascularização Fisiológica/fisiologia , Doenças Vasculares Periféricas/patologia , Doenças Vasculares Periféricas/terapia , Próteses e Implantes , Suínos , Cicatrização
20.
PLoS One ; 15(2): e0228872, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32069321

RESUMO

This study has investigated the immediate effect of induced hindlimb length difference on hindlimb lameness measured as differences in minimum (Pmin) and maximum (Pmax) pelvic heights in 16 horses trotting in a straight line and lungeing on both hard and soft surfaces with body-mounted inertial sensors. Hindlimb length differences were induced by applying an Easyboot Glue-on shoe to one hindlimb. Changes in Pmin and Pmax with induced hindlimb length difference were assessed with a two-way repeated-measures ANOVA with trial (straight, lunge with inside limb elevation, lunge with outside limb elevation) and surface (hard, soft) as within-subject factors. Change in Pmin, indicating an impact-type lameness, in the hind limb with the elevation, was significant in both the straight line and while lunging on both hard and soft surfaces. Change in Pmax, indicating pushoff-type lameness, in the opposite, non-elevated hind limb, was significant when trotting in a straight line but not while lunging.


Assuntos
Membro Posterior/patologia , Doenças dos Cavalos/diagnóstico , Coxeadura Animal/diagnóstico , Animais , Fenômenos Biomecânicos , Feminino , Marcha/fisiologia , Análise da Marcha/métodos , Análise da Marcha/veterinária , Membro Posterior/fisiopatologia , Doenças dos Cavalos/patologia , Doenças dos Cavalos/fisiopatologia , Cavalos , Coxeadura Animal/patologia , Coxeadura Animal/fisiopatologia , Masculino , Movimento/fisiologia , Pelve/fisiopatologia
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