Defining matrix Gla protein expression in the Dunkin-Hartley guinea pig model of spontaneous osteoarthritis

Abstract Background Matrix Gla (γ-carboxyglutamate) protein (MGP) is considered a strong inhibitor of ectopic calcification, and it has been associated with OA severity, although not conclusively. We utilized male Dunkin-Hartley (DH) guinea pigs to investigate the expression of MGP throughout aging and disease pathogenesis in a spontaneous model. Method Twenty-five male DH guinea pigs were obtained and nurtured to several timepoints, and then randomly and equally divided by age into five subgroups (1-, 3-, 6-, 9-, and 12-months, with the 1-month group as the reference group). DH guinea pigs in each group were euthanized at the designated month-age and the left or right medial tibial plateaus cartilages were randomly excised. OA severity was described by modified Mankin Score (MMS) at microscopy (Safranin O/Fast Green stain). Proteomic evaluation using isobaric tags for relative and absolute quantification (iTRAQ) was performed to validate the age-related changes in the MGP profiles, and immunohistochemistry (IHC) methods were applied for semi-quantitative determination of MGP expression in articular cartilage. Results The histopathologic findings validated the increasing severity of cartilage degeneration with age in the DH guinea pigs. The MMS showed significant, stepwise (every adjacent comparison P < 0.05) disease progression with month-age. The iTRAQ indicated that MGP levels increased significantly with advancing age (P < 0.05), as supported by the IHC result (P < 0.05). Conclusion Increased expression of MGP in male DH guinea pigs was present throughout aging and disease progression and may be link to increased OA severity. Further studies are needed to investigate and confirm the association between MGP levels and OA severity.

Download Full-text

Abstract 248: Age-specific Differences in Outcomes Following Isoproterenol-induced Sudden Cardiac Death in Guinea Pigs

Circulation Research ◽

10.1161/res.119.suppl_1.248 ◽

2016 ◽

Vol 119 (suppl_1) ◽

Author(s):

Kathleen C Woulfe ◽

Sarah Chau ◽

Lori A Walker ◽

Christine Tompkins ◽

Carmen C Sucharov ◽

...

Keyword(s):

Sudden Death ◽

Guinea Pigs ◽

Ventricular Arrhythmias ◽

Molecular Mechanisms ◽

Calcium Handling ◽

Initial Exposure ◽

Age Related ◽

Volatile Anesthesia ◽

Pediatric Heart Failure ◽

Guinea Pig Model

Background: The pathophysiological mechanisms involved in adult and pediatric heart failure (HF) are unique. One example of clinical differences in these two patient populations is the need for primary prevention implantable defibrillators (ICDs) in adults with HF, whereas pediatric HF patients infrequently have ventricular arrhythmias and rarely require ICDs. To better understand the age-specific molecular mechanisms involved in HF, we are developing a guinea pig model of pediatric HF. We have found age-specific differences in guinea pigs acutely treated with isoproterenol (ISO). Additionally, initial exposure to ISO leads to sudden death in guinea pigs. This sudden death has previously been reported as an interaction with an inhaled volatile anesthesia. We hypothesized that isoproterenol is leading to sustained ventricular arrhythmias in guinea pigs. Methods: Adult (n= 11) and young (n= 50) guinea pigs were treated with vehicle, 16 mg/kg/day or 32 mg/kg/day of ISO by osmotic pump (Alzet) implanted under isoflurane anesthesia. Cardiac rhythm was monitored in a subset via simultaneously implanted Linq recorders (Medtronic, n= 12). Results: Acute exposure to ISO in the presence or absence of isoflurane resulted in sudden death in adult and young guinea pigs. Four of the 6 adult guinea pigs exposed to ISO died even with attempts at resuscitation. In contrast, 61% (22 out of 36) of the young guinea pigs treated with ISO arrested and 60% (13 out of 22) were rescued with chest compressions. Analysis of the heart rhythms demonstrated that the guinea pigs experienced ventricular fibrillation. The arrhythmia was transient in the young guinea pigs, but sustained in the adult. Conclusions: Acute ISO leads to age-dependent differences in arrhythmias and sudden death in guinea pigs. Contrary to prior reports, this response occurs independently of isoflurane. These age-specific differences suggest unique mechanisms in calcium handling, which can lead to arrhythmias. Guinea pigs may be a useful model for the age-related differences in HF arrhythmias seen in humans. A better understanding of these differences may lead to the development of therapies to protect adult HF patients from arrhythmias.

Download Full-text

Intravitreal brimonidine inhibits form-deprivation myopia in guinea pigs

Eye and Vision ◽

10.1186/s40662-021-00248-0 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Yifang Yang ◽

Junshu Wu ◽

Defu Wu ◽

Qi Wei ◽

Tan Zhong ◽

...

Keyword(s):

Guinea Pig ◽

Intravitreal Injection ◽

Guinea Pigs ◽

Intravitreal Injections ◽

Eye Drops ◽

Rna Seq ◽

Myopia Progression ◽

Expression Levels ◽

Guinea Pig Model ◽

Administration Methods

Abstract Background The use of ocular hypotensive drugs has been reported to attenuate myopia progression. This study explores whether brimonidine can slow myopia progression in the guinea pig form-deprivation (FD) model. Methods Three-week-old pigmented male guinea pigs (Cavia porcellus) underwent monocular FD and were treated with 3 different methods of brimonidine administration (eye drops, subconjunctival or intravitreal injections). Four different concentrations of brimonidine were tested for intravitreal injection (2 μg/μL, 4 μg/μL, 20 μg/μL, 40 μg/μL). All treatments continued for a period of 21 days. Tonometry, retinoscopy, and A-scan ultrasonography were used to monitor intraocular pressure (IOP), refractive error and axial length (AL), respectively. On day 21, guinea pigs were sacrificed for RNA sequencing (RNA-seq) to screen for associated transcriptomic changes. Results The myopia model was successfully established in FD animals (control eye vs. FD eye, respectively: refraction at day 20, 0.97 ± 0.18 D vs. − 0.13 ± 0.38 D, F = 6.921, P = 0.02; AL difference between day 0 and day 21, 0.29 ± 0.04 mm vs. 0.45 ± 0.03 mm, F = 11.655, P = 0.004). Among the 3 different brimonidine administration methods, intravitreal injection was the most effective in slowing myopia progression, and 4 μg/μL was the most effective among the four different concentrations of brimonidine intravitreal injection tested. The AL and the refraction of the brimonidine intravitreal injection group was significantly shorter or more hyperopic than those of other 2 groups. Four μg/μL produced the smallest difference in AL and spherical equivalent difference values. FD treatment significantly increased the IOP. IOP was significantly lower at 1 day after intravitreal injections which was the lowest in FD eye of intravitreal injection of brimonidine. At day 21, gene expression analyses using RNA-seq showed upregulation of Col1a1 and Mmp2 expression levels by intravitreal brimonidine. Conclusions Among the 3 different administration methods, intravitreal injection of brimonidine was the most effective in slowing myopia progression in the FD guinea pig model. Intravitreal brimonidine at 4 μg/μL significantly reduced the development of FD myopia in guinea pigs. Expression levels of the Col1a1 and Mmp2 genes were significantly increased in the retinal tissues of the FD-Inj-Br group.

Download Full-text

Disruption of Abcc6 Transporter in Zebrafish Causes Ocular Calcification and Cardiac Fibrosis

International Journal of Molecular Sciences ◽

10.3390/ijms22010278 ◽

2020 ◽

Vol 22 (1) ◽

pp. 278

Author(s):

Jianjian Sun ◽

Peilu She ◽

Xu Liu ◽

Bangjun Gao ◽

Daqin Jin ◽

...

Keyword(s):

Vitamin K ◽

Cardiac Fibrosis ◽

Clinical Manifestations ◽

Pseudoxanthoma Elasticum ◽

Matrix Gla Protein ◽

Ectopic Calcification ◽

Transcription Activator ◽

Multisystem Disorder ◽

Ectopic Mineralization ◽

Extensive Calcification

Pseudoxanthoma elasticum (PXE), caused by ABCC6/MRP6 mutation, is a heritable multisystem disorder in humans. The progressive clinical manifestations of PXE are accompanied by ectopic mineralization in various connective tissues. However, the pathomechanisms underlying the PXE multisystem disorder remains obscure, and effective treatment is currently available. In this study, we generated zebrafish abcc6a mutants using the transcription activator-like effector nuclease (TALEN) technique. In young adult zebrafish, abcc6a is expressed in the eyes, heart, intestine, and other tissues. abcc6a mutants exhibit extensive calcification in the ocular sclera and Bruch’s membrane, recapitulating part of the PXE manifestations. Mutations in abcc6a upregulate extracellular matrix (ECM) genes, leading to fibrotic heart with reduced cardiomyocyte number. We found that abcc6a mutation reduced levels of both vitamin K and pyrophosphate (PPi) in the serum and diverse tissues. Vitamin K administration increased the gamma-glutamyl carboxylated form of matrix gla protein (cMGP), alleviating ectopic calcification and fibrosis in vertebrae, eyes, and hearts. Our findings contribute to a comprehensive understanding of PXE pathophysiology from zebrafish models.

Download Full-text

Relationship between potency of L-isoprenaline and β-adrenoceptor density estimated in single cells from tracheal smooth muscles of guinea pigs of different ages

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y92-059 ◽

1992 ◽

Vol 70 (4) ◽

pp. 458-461 ◽

Cited By ~ 2

Author(s):

Issei Takayanagi ◽

Mitsutoshi Satoh ◽

Noriko Kokubu ◽

Teruko Kato

Keyword(s):

Guinea Pig ◽

Guinea Pigs ◽

Dissociation Constants ◽

Specific Binding ◽

Single Cells ◽

Regression Line ◽

Smooth Muscles ◽

Receptor Density ◽

Age Related ◽

Β Receptor

An age-related change in potency of L-isoprenaline in the presence of ascorbic acid, desmethylimipramine, corticosterone, pargyline, and phentolamine was obtained in tracheal strips from guinea pigs of differing ages between 6 and 40 weeks. The potency in the strips from 100-week-old guinea pigs did not significantly differ from that in strips from 40-week-old animals. Single cells were prepared from the tracheal muscles of 6-, 10-, 40-, and 100-week-old guinea pigs. The specific binding of [3H]dihydroalprenolol to the single cells was saturable. The dissociation constants of [3H]dihydroalprenolol were in good agreement with those of the membrane fractions from the guinea-pig tracheal muscles, and did not change with age. An excellent relationship between the potency of L-isoprenaline and the maximum binding of [3H]dihydroalprenolol estimated in the preparations from 6- to 40-week-old guinea pigs was found, suggesting that the increase in the potency of L-isoprenaline is due to the increase in the maximum binding or receptor density. The value in the preparations from 100-week-old guinea pigs deviated significantly from the regression line. This suggests the possibility that the decrease in potency in the strips from 100-week-old animals is due to a change in post β-receptor processes in responsiveness.Key words: guinea-pig trachea, single cells, β-receptor density, ageing, dissociation constant.

Download Full-text

Quantitative cartilage degeneration associated with spontaneous osteoarthritis in a guinea pig model

Journal of Magnetic Resonance Imaging ◽

10.1002/jmri.22867 ◽

2011 ◽

Vol 35 (4) ◽

pp. 891-898 ◽

Cited By ~ 16

Author(s):

Matthew C. Fenty ◽

George R. Dodge ◽

Victor Babu Kassey ◽

Walter R.T. Witschey ◽

Arijitt Borthakur ◽

...

Keyword(s):

Guinea Pig ◽

Cartilage Degeneration ◽

Pig Model ◽

Guinea Pig Model

Download Full-text

Location of Intra- and Extracellular M. tuberculosis Populations in Lungs of Mice and Guinea Pigs during Disease Progression and after Drug Treatment

PLoS ONE ◽

10.1371/journal.pone.0017550 ◽

2011 ◽

Vol 6 (3) ◽

pp. e17550 ◽

Cited By ~ 62

Author(s):

Donald R. Hoff ◽

Gavin J. Ryan ◽

Emily R. Driver ◽

Cornelius C. Ssemakulu ◽

Mary A. De Groote ◽

...

Keyword(s):

Drug Treatment ◽

Disease Progression ◽

Guinea Pigs

Download Full-text

Differential Contribution of Bacillus anthracis Toxins to Pathogenicity in Two Animal Models

Infection and Immunity ◽

10.1128/iai.00244-12 ◽

2012 ◽

Vol 80 (8) ◽

pp. 2623-2631 ◽

Cited By ~ 29

Author(s):

Haim Levy ◽

Shay Weiss ◽

Zeev Altboum ◽

Josef Schlomovitz ◽

Itai Glinert ◽

...

Keyword(s):

Animal Models ◽

Guinea Pigs ◽

Protective Antigen ◽

Comprehensive Evaluation ◽

Lethal Factor ◽

Rabbit Model ◽

Content Type ◽

Edema Factor ◽

Genes Encoding ◽

Guinea Pig Model

ABSTRACTThe virulence ofBacillus anthracis, the causative agent of anthrax, stems from its antiphagocytic capsule, encoded by pXO2, and the tripartite toxins encoded by pXO1. The accepted paradigm states that anthrax is both an invasive and toxinogenic disease and that the toxins play major roles in pathogenicity. We tested this assumption by a systematic study of mutants with combined deletions of thepag,lef, andcyagenes, encoding protective antigen (PA), lethal factor (LF), and edema factor (EF), respectively. The resulting seven mutants (single, double, and triple) were evaluated following subcutaneous (s.c.) and intranasal (i.n.) inoculation in rabbits and guinea pigs. In the rabbit model, virulence is completely dependent on the presence of PA. Any mutant bearing apagdeletion behaved like a pXO1-cured mutant, exhibiting complete loss of virulence with attenuation indices of over 2,500,000 or 1,250 in the s.c. or i.n. route of infection, respectively. In marked contrast, in guinea pigs, deletion ofpagor even of all three toxin components resulted in relatively moderate attenuation, whereas the pXO1-cured bacteria showed complete attenuation. The results indicate that a pXO1-encoded factor(s), other than the toxins, has a major contribution to the virulence mechanism ofB. anthracisin the guinea pig model. These unexpected toxin-dependent and toxin-independent manifestations of pathogenicity in different animal models emphasize the importance and need for a comprehensive evaluation ofB. anthracisvirulence in general and in particular for the design of relevant next-generation anthrax vaccines.

Download Full-text

The Expression of miR-155-5p and Local Matrix Gla Protein in Meningiomas

Revista Romana de Medicina de Laborator ◽

10.2478/rrlm-2021-0020 ◽

2021 ◽

Vol 29 (3) ◽

pp. 299-306

Author(s):

Simona Roxana Gheorghe ◽

Cătălin Marian ◽

Ligia Gabriela Tătăranu ◽

Anica Dricu ◽

Cees Vermeer ◽

...

Keyword(s):

Messenger Rna ◽

Molecular Classification ◽

Micro Rna ◽

Matrix Gla Protein ◽

World Health ◽

Ectopic Calcification ◽

Chain Reaction ◽

The World ◽

Polymerase Chain ◽

Health Organization

Abstract Meningiomas are classified by the World Health Organization (WHO) in three grades, based on morphological features. Independent of this grading, the presence of calcification in meningiomas influences their growth rate. The messenger RNA of matrix Gla protein (MGP), an extra-hepatic protein with different conformations involved in the homeostasis of ectopic calcification has been found in meningiomas and was shown to be regulated in breast cancer by miR-155-5p, a specific micro RNA. Therefore, we investigated the expression of miR-155-5p and its relationship with local MGP conformations in different grade meningiomas. According to the WHO classification, our 41 samples of meningiomas were stratified in groups WHO I and WHO II. Using real time polymerase chain reaction, we observed a higher miR-155-5p expression in group WHO I versus group WHO II [with a fold change (FC) of 3.83, p=0.027)]. Moreover, the expression of miR-155-5p was higher in calcified tumors compared to non-calcified tumors in all samples (FC=3.01, p=0.047) and in group WHO I (FC=3.65, p=0.048). Utilizing immunohistochemistry, we determined the concurrent presence of all MGP conformations in calcified meningiomas. This study was the first to establish higher miR-155-5p expression in grade WHO I and calcified meningiomas, which could improve molecular classification and targeted therapy and also the presence of all MGP conformations in calcified meningiomas, confirming the existence of an anti-calcification mechanism in meningiomas..

Download Full-text

Use of quantitative real-time PCR for studying the dissemination of Leptospira interrogans in the guinea pig infection model of leptospirosis

Journal of Medical Microbiology ◽

10.1099/jmm.0.008169-0 ◽

2009 ◽

Vol 58 (5) ◽

pp. 648-655 ◽

Cited By ~ 39

Author(s):

Kristel Lourdault ◽

Florence Aviat ◽

Mathieu Picardeau

Keyword(s):

Guinea Pig ◽

Real Time ◽

Real Time Pcr ◽

Guinea Pigs ◽

Infection Model ◽

Avirulent Strain ◽

Leptospira Interrogans ◽

Quantitative Real Time Pcr ◽

Guinea Pig Model

The dynamics of leptospirosis infection have been poorly studied. The purpose of this study was to determine the LD50, rate of bacterial dissemination, histopathology and antibody responses against leptospira following inoculation with the highly virulent Leptospira interrogans Fiocruz L1-130 strain in a guinea pig model of leptospirosis. Three routes of infection (intraperitoneal, conjunctival and subcutaneous inoculation) were used to establish disease in guinea pigs. The size and kinetics of leptospiral burdens in the blood and tissues of infected animals were determined over a 1 week course of infection using quantitative real-time PCR (qPCR). Bacteraemia peaked at day 5 post-infection reaching more than 5×104 leptospires ml−1. The highest spirochaetal load was found in the liver and kidneys, and was associated with alterations in organ tissues and a decline in liver and kidney functions. In contrast, lesions and bacteria were not detected in guinea pigs infected with an avirulent strain derived from a high-passage-number in vitro-passaged variant of the Fiocruz L1-130 strain. The use of qPCR supports the findings of earlier studies and provides an easy and reliable method for the quantification of L. interrogans in the tissues of infected animals. qPCR will be used in future studies to evaluate the efficacy of vaccine candidates against leptospirosis and the virulence of selected L. interrogans mutants relative to the parental strain.

Download Full-text