Convergent dwarfism consequences of minipigs under independent artificial selections.

BACKGROUND: Currently, diverse minipigs have acquired a common dwarfism phenotype through independent artificial selections. Characterizing the population and genetic diversity in minipigs is important to unveil genetic mechanisms regulating their body sizes and effects of independent artificial selections on those genetic mechanisms. However, full understanding for the genetic mechanisms and phenotypic consequences in minipigs still lag behind. RESULTS: Here, using whole genome sequencing data of 41 pig breeds, including eight minipigs, we identified a large genomic diversity in a minipig population compared to other pig populations in terms of population structure, demographic signatures, and selective signatures. Selective signatures reveal diverse biological mechanisms related to body size in minipigs. We also found evidence for neural development mechanism as a minipig-specific body size regulator. Interestingly, selection signatures within those mechanisms containing neural development are also highly different among minipig breeds. Despite those large genetic variances, PLAG1, CHM, and ESR1 are candidate key genes regulating body size which experience different differentiation directions in different pig populations. CONCLUSIONS: These findings present large variances of genetic structures, demographic signatures, and selective signatures in the minipig population. They also highlight how different artificial selections with large genomic diversity have shaped the convergent dwarfism.

Biomechanical, biochemical, and histological characterization of sacroiliac joint cartilage in the Yucatan minipig.

Although the sacroiliac (SI) joint can be a source of lower back and buttock pain, no comprehensive characterization studies on SI cartilage have been conducted. Using the minipig as a large animal model, this study conducted the first biomechanical, biochemical, and histological characterization of SI joint cartilage. Because previous literature has reported that sacral cartilage and iliac cartilage within the SI joint are histologically distinct, concomitantly it was expected that functional properties of the sacral cartilage would differ from those of the iliac cartilage. Creep indentation, uniaxial tension, biochemical, and histological analyses were conducted on the sacral and iliac cartilage of skeletally mature female Yucatan minipigs (n = 6-8 for all quantitative tests). Concurring with prior literature, the iliac cartilage appeared to be more fibrous than the sacral cartilage. Glycosaminoglycan content was 2.2 times higher in the sacral cartilage. The aggregate modulus of the sacral cartilage was 133 ± 62 kPa, significantly higher than iliac cartilage, which only had an aggregate modulus of 51 ± 61 kPa. Tensile testing was conducted in both cranial-caudal and ventral-dorsal axes, and Young's modulus values ranged from 2.5 ± 1.5 MPa to 13.6 ± 1.5 MPa, depending on anatomical structure (i.e., sacral vs. iliac) and orientation of the tensile test. The Young's modulus of sacral cartilage was 5.5 times higher in the cranial-caudal axis and 2.0 times higher in the ventral-dorsal axis than the iliac cartilage. The results indicate that the sacral and iliac cartilages are functionally distinct from each other. Understanding the distinct differences between sacral and iliac cartilage provides insight into the structure and function of the SI joint, which may inform future research aimed at repairing SI joint cartilage.

Exosomes Derived from Adipose Mesenchymal Stem Cells Promote Regeneration of Injured Liver in Minipigs.

Hepatic ischemia/reperfusion injury (IRI) is an important factor affecting liver regeneration and functional recovery postoperatively. Many studies have suggested that mesenchymal stem cells (MSCs) contribute to hepatic tissue repair and functional recovery through paracrine mechanisms mediated by exosomes. Minipigs exhibit much more similar characteristics of the liver to those of humans than rodents. This study aimed to explore whether exosomes from adipose-derived MSCs (ADSCs-exo) could actively promote liver regeneration after hepatectomy combined with HIRI in minipigs and the role they play in the cell proliferation process. This study also compared the effects and differences in the role of ADSCs and ADSCs-exo in the inflammatory response and liver regeneration. The results showed that ADSCs-exo suppressed histopathological changes and reduced inflammatory infiltration in the liver; significantly decreased levels of ALT, TBIL, HA, and the pro-inflammatory cytokines TNF-α, IL-6, and CRP; increased levels of the anti-inflammatory cytokine IL-10 and the pro-regeneration factors Ki67, PCNA, CyclinD1, HGF, STAT3, VEGF, ANG1, ANG2; and decreased levels of the anti-regeneration factors SOCS3 and TGF-ß. These indicators above showed similar changes with the ADSCs intervention group. Indicating that ADSCs-exo can exert the same role as ADSCs in regulating inflammatory responses and promoting liver regeneration. Our findings provide experimental evidence for the possibility that ADSCs-exo could be considered a safe and effective cell-free therapy to promote regeneration of injured livers.

Pharmacokinetics and pharmacodynamics of standard nerve agent medical countermeasures in Göttingen Minipigs.

Animal research continues to serve a critical role in the testing and development of medical countermeasures. The Göttingen minipig, developed for laboratory research, may provide many benefits for addressing research questions within chemical defense. Targeted development of the Göttingen minipig model could reduce reliance upon non-human primates, and improve study design, statistical power, and throughput to advance medical countermeasures for regulatory approval and fielding. In this vein, we completed foundational pharmacokinetics and physiological safety studies of intramuscularly administered atropine sulfate, pralidoxime chloride (2-PAM), and diazepam across a broad range of doses (1-6 autoinjector equivalent) using adult male Göttingen minipigs (n=11; n=4-8/study) surgically implanted with vascular access ports and telemetric devices to monitor cardiovascular, respiratory, arterial pressure, and temperature signals. Pharmacokinetic data were orderly and the concentration maximum mirrored available human data at comparably scaled doses clearly for atropine, moderately for 2-PAM, and poorly for diazepam. Time to peak concentration approximated 2, 7, and 20 min for atropine, 2-PAM, and diazepam, respectively, and the elimination half-life of these drugs approximated 2 hr (atropine), 3 hr (2-PAM), and 8 hr (diazepam). Atropine sulfate dose-dependently increased the magnitude and duration of tachycardia and decreased the PR and ST intervals (consistent with findings obtained from other species). Mild hypothermia was observed at the highest diazepam dose. Göttingen minipigs appear to provide a ready and appropriate large animal alternative to non-human primates, and further development and evaluation of novel nerve agent medical countermeasures and treatment strategies in this model are justified.

Changes in hearing function and intracochlear morphology after electrode array insertion in minipigs.

BACKGROUND: In temporal bone specimens from long-term cochlear implant users, foreign body response within the cochlea has been demonstrated. However, how hearing changes after implantation and fibrosis progresses within the cochlea is unknown. OBJECTIVES: To investigate the short-term dynamic changes in hearing and cochlear histopathology in minipigs after electrode array insertion. MATERIAL AND METHODS: Twelve minipigs were selected for electrode array insertion (EAI) and the Control. Hearing tests were performed preoperatively and on 0, 7, 14, and 28 day(s) postoperatively, and cochlear histopathology was performed after the hearing tests on 7, 14, and 28 days after surgery. RESULTS: Electrode array insertion had a significant effect for the frequency range tested (1 kHz-20kHz). Exudation was evident one week after electrode array insertion; at four weeks postoperatively, a fibrous sheath formed around the electrode. At each time point, the endolymphatic hydrops was found; no significant changes in the morphology and packing density of the spiral ganglion neurons were observed. CONCLUSIONS AND SIGNIFICANCE: The effect of electrode array insertion on hearing and intracochlear fibrosis was significant. The process of fibrosis and endolymphatic hydrops seemed to not correlate with the degree of hearing loss, nor did it affect spiral ganglion neuron integrity in the 4-week postoperative period.

Excessive sucrose consumption reduces synaptic density and increases cannabinoid receptors in Göttingen minipigs.

Diets high in sucrose and fat are becoming more prevalent the world over, accompanied by a raised prevalence of cardiovascular diseases, cancers, diabetes, obesity, and metabolic syndrome. Clinical studies link unhealthy diets with the development of mental health disorders, particularly depression. Here, we investigate the effects of 12 days of sucrose consumption administered as 2 L of 25% sucrose solution daily for 12 days in Göttingen minipigs on the function of brain receptors involved in reward and motivation, regulating feeding, and pre- and post-synaptic mechanisms. Through quantitative autoradiography of cryostat sections containing limbic brain regions, we investigated the effects of sucrose restricted to a 1-h period each morning, on the specific binding of [3H]raclopride on dopamine D2/3 receptors, [3H]UCB-J at synaptic vesicle glycoprotein 2A (SV2A), [3H]MPEPγ at metabotropic glutamate receptor subtype 5 (mGluR5) and [3H]SR141716A at the cannabinoid receptor 1 (CB1). Compared to control diet animals, the sucrose group showed significantly lower [3H]UCB-J and [3H]MPEPγ binding in the prefrontal cortex. The sucrose-consuming minipigs showed higher hippocampal CB1 binding, but unaltered dopamine D2/3 binding compared to the control group. We found that the sucrose diet reduced the synaptic density marker while increasing CB1 binding in limbic brain structures, which may subserve maladaptive changes in appetite regulation and feeding. Further studies of the effects of diets and lifestyle habits on brain neuroreceptor and synaptic density markers are warranted.

Dietary probiotic and synbiotic supplementation starting from maternal gestation improves muscular lipid metabolism in offspring piglets by reshaping colonic microbiota and metabolites.

Probiotics and synbiotics have been intensively used in animal husbandry due to their advantageous roles in animals' health. However, there is a paucity of research on probiotic and synbiotic supplementation from maternal gestation to the postnatal growing phases of offspring piglets. Thus, we assessed the effects of dietary supplementation of these two additives to sows and offspring piglets on skeletal muscle and body metabolism, colonic microbiota composition, and metabolite profiles of offspring piglets. Pregnant Bama mini-pigs and their offspring piglets (after weaning) were fed either a basal diet or a basal diet supplemented with antibiotics, probiotics, or synbiotics. At 65, 95, and 125 days old, eight pigs per group were euthanized and sampled for analyses. Probiotics increased the intramuscular fat content in the psoas major muscle (PMM) at 95 days old, polyunsaturated fatty acid (PUFA) and n-3 PUFA levels in the longissimus dorsi muscle (LDM) at 65 days old, C16:1 level in the LDM at 125 days old, and upregulated ATGL, CPT-1, and HSL expressions in the PMM at 65 days old. Synbiotics increased the plasma HDL-C level at 65 days old and TC level at 65 and 125 days old and upregulated the CPT-1 expression in the PMM at 125 days old. In addition, probiotics and synbiotics increased the plasma levels of HDL-C at 65 days old, CHE at 95 days old, and LDL-C at 125 days old, while decreasing the C18:1n9t level in the PMM at 65 days old and the plasma levels of GLU, LDH, and TG at 95 days old. Microbiome analysis showed that probiotic and synbiotic supplementation increased colonic Actinobacteria, Firmicutes, Verrucomicrobia, Faecalibacterium, Pseudobutyrivibrio, and Turicibacter abundances. However, antibiotic supplementation decreased colonic Actinobacteria, Bacteroidetes, Prevotella, and Unclassified_Lachnospiraceae abundances. Furthermore, probiotic and synbiotic supplementation was associated with alterations in 8, 7, and 10 differential metabolites at three different age stages. Both microbiome and metabolome analyses showed that the differential metabolic pathways were associated with carbohydrate, amino acid, and lipid metabolism. However, antibiotic supplementation increased the C18:1n9t level in the PMM at 65 days old and xenobiotic biodegradation and metabolism at 125 days old. In conclusion, sow-offspring's diets supplemented with these two additives showed conducive effects on meat flavor, nutritional composition of skeletal muscles, and body metabolism, which may be associated with the reshaping of colonic microbiota and metabolites. However, antibiotic supplementation has negative effects on colonic microbiota composition and fatty acid composition in the PMM. IMPORTANCE: The integral sow-offspring probiotic and synbiotic supplementation improves the meat flavor and the fatty acid composition of the LDM to some extent. Sow-offspring probiotic and synbiotic supplementation increases the colonic beneficial bacteria (including Firmicutes, Verrucomicrobia, Actinobacteria, Faecalibacterium, Turicibacter, and Pseudobutyrivibrio) and alters the colonic metabolite profiles, such as guanidoacetic acid, beta-sitosterol, inosine, cellobiose, indole, and polyamine. Antibiotic supplementation in sow-offspring's diets decreases several beneficial bacteria (including Bacteroidetes, Actinobacteria, Unclassified_Lachnospiraceae, and Prevotella) and has a favorable effect on improving the fatty acid composition of the LDM to some extent, while presenting the opposite effect on the PMM.

Crude protein content in diets associated with intestinal microbiome and metabolome alteration in Huanjiang mini-pigs during different growth stages.

Introduction: Adequate crude protein (CP) content in diets plays a crucial role in the intestinal health of the animal. This study investigated the impacts of CP content in diets on the intestinal microbiome and metabolome profiles in growing Huanjiang mini-pigs. Methods: A total of 360 pigs with similar body weight (BW) were allocated for three independent feeding trials based on three different BW stages, including (i) 5-10 kg BW, diets consisting of 14, 16, 18, 20, and 22% CP content; (ii) 10-20 kg BW, diets consisting of 12, 14, 16, 18, and 20% CP content; and (iii) 20-30 kg BW, diets consisting of 10, 12, 14, 16, and 18% CP content. These experiments lasted 28, 28, and 26 days, respectively. Results: The results showed that the Shannon and Simpson indices were decreased (p < 0.05) in the ileum of pigs in response to the 14-18% CP compared with the 20% CP content at 5-10 kg BW stage, while diets containing 12 and 14% CP had higher Chao1 (p < 0.05) and Shannon (p = 0.054) indices compared with 18% CP at 20-30 kg BW stage. Compared with the 20% CP, the diet containing 16% CP displayed an increasing trend (p = 0.089) of Firmicutes abundance but had decreased (p = 0.056) Actinobacteria abundance in the jejunum at 5-10 kg BW stage. In addition, a diet containing 16% CP had higher Lactobacillus abundance in the jejunum and ileum compared with the 18, 20, and 22% CP, while had lower Sphingomonas and Pelomonas abundances in the jejunum and Streptococcus abundance in the ileum compared with the diet containing 22% CP (p < 0.05). Diets containing lower CP content altered differential metabolites in the small intestine at the early stage, while higher CP content had less impact. Conclusion: These findings suggest that a diet containing lower CP content (16% CP) may be an appropriate dietary CP content for 5-10 kg Huanjiang mini-pigs, as 16% CP content in diet has shown beneficial impacts on the intestinal microbiome and metabolome profiles at the early growth stage of pigs.

The Goettingen minipig as an experimental model in wound-healing studies.

Background: Deep dermal wounds in extensive burns and chronic wound-healing disorders represent a significant medical problem and require a high level of therapy to reduce the risk of infection and other long-term consequences, such as amputation. A better understanding of the wound-healing processes is essential, and animal models are indispensable to fundamental research. Objective: This study aimed to provide a transparent protocol and prove the effectiveness of an in vivo porcine model using Goettingen minipigs for wound-healing studies. Material and methods: Thirteen female Goettingen minipigs were kept in species-appropriate housing and were treated according to the German law for the protection of animals. The study was performed with permission from the local ethical review committee of animal welfare. The experimental procedure for studying dermal regeneration in 102 full-thickness wounds through clinical observation and histological analysis, focusing on neodermal formation, is described in detail. Results: The Goettingen minipig model proved to be suitable in wound-healing studies. The dermal regeneration was evident and viewable without wound contamination or any rejection reaction. The histological evaluations were also reliable and clearly presented the optimized wound healing of deep dermal wounds using the different therapeutic approaches. Conclusion: Given the great clinical need for alternative or complementary therapies, we considered the Goettingen minipig trial a reliable, ethically justifiable, effective, and reproducible in vivo model for wound-healing studies.

Reproductive ability of minipigs as surrogates for somatic cell nuclear transfer.

Pigs are genetically, anatomically, and physiologically similar to humans. Recently, pigs are in the spotlight as a suitable source animal for xenotransplantation. However, to use pigs as source animals, pigs should be raised in designated pathogen-free facilities. There is abundant data from embryo transfer (ET) experiments using farm pigs as surrogates, but data on ET experiments using minipigs are scarce. Eighty minipigs were used for ET experiments and after transplantation, the implantation and delivery rates were investigated. It was also confirmed whether the pregnancy rate could be increased by changing the condition or surgical method of the surrogate. In the case of minipigs that gave birth, the size of the fetal sac on the 28th day of ET was also measured. The factors that can affect the pregnancy rate such as estrus synchronization program, ovulation status at the time of ET, the number of repeated ET surgeries, and the ET sites, were changed, and the differences on the pregnancy rate were observed. However there were no significant differences in pregnancy rate in minipigs. The diameter of the implanted fetal sac on the 28th day after ET in the minipigs whose delivery was confirmed was calculated to be 4.7 ± 0.5 cm. In conclusion, there were no significant differences in pregnancy rate of minipigs in the comparative experiment on various factors affecting the pregnancy rate. However, additional experiments and analyses are needed due to the large individual differences of the minipigs.

Preclinical pharmacokinetic investigation of the bioavailability and skin distribution of HY-072808 ointment, a novel drug candidate for the treatment of atopic dermatitis, in minipigs by a newly LC-MS/MS method.

HY-072808 is a novel phosphodiesterase 4 inhibitor clinically used for topical atopic dermatitis treatment. Cytochrome P450 enzymes are involved in transforming it into major metabolite ZZ-24. An efficient UPLC-MS/MS method was established to detect HY-072808 and ZZ-24 in plasma and skin tissues of minipigs.One-step protein precipitation was performed with acetonitrile. Subsequently, elution was served with a methanol and water gradient containing 0.1% formic acid for 3.5 min. The plasma and skin tissue concentrations of HY-072808 and ZZ-24 showed good linearity from 0.200 to 200 ng/mL.The experimental minipigs exhibited low systemic exposure and bioavailability of 3.1-7.6% after transdermal application of 1-4% HY-072808 ointment. Multiple topical administrations over seven consecutive days showed a minor accumulation in systemic exposure, with accumulation factors of 2.3 and 4.0 for HY-072808 and ZZ-24, respectively.The distribution of HY-072808 ointment among different cortical layers in minipigs was studied for the first time. Following transdermal application of 2% HY-072808 ointment, the concentration in plasma and skin tissues in the order of epidermis > dermis > subcutaneous tissue ≈ subcutaneous muscle ≈ plasma; at 48 h after the administration, the epidermis and dermis still had a high concentration of the drug.

Toxicity of a novel antifungal agent (ATB1651 gel) in Yucatan minipigs (Sus scrofa) following 4 weeks of daily dermal administration.

ATB1651 gel is an antifungal drug candidate that enhances antifungal activity through substitution of several aryl rings, alkyl chains, and methyl groups. To ensure safety of use of ATB1651 gel, assessment of its potentially toxic side effects is necessary. In this study, we examined the repeated-dose toxicity of ATB1651 gel to Yucatan minipigs (Sus scrofa) in accordance with the Good Laboratory Practice guidelines. Five doses of ATB1651 gel (0%, 0.2%, 0.5%, 1.0%, 3.0%) were administered dermally to the left and right flanks of 38 minipigs daily for 4 weeks. Mortality, clinical symptoms, dermal scores, body weights, and physiological, biochemical, pathological, and toxicokinetic analyses were performed after the treatment period. No systemic toxicological damage was observed in either male or female minipigs regardless of dose; however, dermal application of ATB1651 gel caused some skin alterations at the application sites. Specifically, erythema and eschar formation, edema, and scabs or raise spots were observed at the application site(s) in males in the 3.0% ATB1651 gel treatment group and in females at ATB1651 gel concentrations ≥ 1.0%, with dermal scores ranging from grade 1 to 2. Additionally, histopathological assay indicated infiltration of different types of inflammatory cells and the presence of pustule/crust at the application site(s) in both males and females at ATB1651 gel concentrations ≥ 0.5%. However, these changes were reversible after a 2-week recovery period and were considered a local irritation effect of ATB1651 gel. The no-observed-adverse-effect level of ATB1651 gel was 3.0% with regard to topical and systemic toxicity in both male and female minipigs. Collectively, our results imply that ATB1651 gel is a safe candidate for clinical development as an antifungal drug with a wide therapeutic window.

Validating a minipig model of reversible cerebral demyelination using human diagnostic modalities and electron microscopy.

BACKGROUND: Inflammatory demyelinating diseases of the central nervous system, such as multiple sclerosis, are significant sources of morbidity in young adults despite therapeutic advances. Current murine models of remyelination have limited applicability due to the low white matter content of their brains, which restricts the spatial resolution of diagnostic imaging. Large animal models might be more suitable but pose significant technological, ethical and logistical challenges. METHODS: We induced targeted cerebral demyelinating lesions by serially repeated injections of lysophosphatidylcholine in the minipig brain. Lesions were amenable to follow-up using the same clinical imaging modalities (3T magnetic resonance imaging, 11C-PIB positron emission tomography) and standard histopathology protocols as for human diagnostics (myelin, glia and neuronal cell markers), as well as electron microscopy (EM), to compare against biopsy data from two patients. FINDINGS: We demonstrate controlled, clinically unapparent, reversible and multimodally trackable brain white matter demyelination in a large animal model. De-/remyelination dynamics were slower than reported for rodent models and paralleled by a degree of secondary axonal pathology. Regression modelling of ultrastructural parameters (g-ratio, axon thickness) predicted EM features of cerebral de- and remyelination in human data. INTERPRETATION: We validated our minipig model of demyelinating brain diseases by employing human diagnostic tools and comparing it with biopsy data from patients with cerebral demyelination. FUNDING: This work was supported by the DFG under Germany's Excellence Strategy within the framework of the Munich Cluster for Systems Neurology (EXC 2145 SyNergy, ID 390857198) and TRR 274/1 2020, 408885537 (projects B03 and Z01).

Efficacy of lysostaphin-coated titanium plates on implant-associated MRSA osteitis in minipigs.

PURPOSE: The growing incidence of implant-associated infections (IAIs) caused by biofilm-forming Staphylococcus aureus in combination with an increasing resistance to antibiotics requires new therapeutic strategies. Lysostaphin has been shown to eliminate this biofilm. Own studies confirm the effectiveness in a murine model. The current study characterizes the effects of lysostaphin-coated plates in an IAI minipig model. METHODS: The femur of 30 minipigs was stabilized with a five-hole plate, a bone defect was created, and in 20 cases methicillin-resistant Staphylococcus aureus was applied. Ten animals served as control group. After 14 days, local debridement, lavage, and plate exchange (seven-hole plate) were performed. Ten of the infected minipigs received an uncoated plate and 10 a lysostaphin-coated plate. On day 84, the minipigs were again lavaged, followed by euthanasia. Bacterial load was quantified by colony-forming units (CFU). Immunological response was determined by neutrophils, as well as interleukins. Fracture healing was assessed radiologically. RESULTS: CFU showed significant difference between infected minipigs with an uncoated plate and minipigs with a lysostaphin-coated plate (p = 0.0411). The infection-related excessive callus formation and calcification was significantly greater in the infected animals with an uncoated plate than in animals with a lysostaphin-coated plate (p = 0.0164/p = 0.0033). The analysis of polymorphonuclear neutrophils and interleukins did not reveal any pioneering findings. CONCLUSION: This study confirms the minipig model for examining IAI. Furthermore, coating of plates using lysostaphin could be a promising tool in the therapeutic strategies of IAI. Future studies should focus on coating technology of implants and on translation into a clinical model.

Comparison of artery diameters in the Aachen minipig serving as a human intracranial in vivo model.

Minipigs are used as in vivo endovascular models, particularly in stroke and aneurysm research. However, detailed knowledge of the diameters of forelimb arteries that are commonly used as surrogates for human brain-supplying arteries are lacking. This study aimed to determine the diameters of forelimb and neck arteries in Aachen minipigs and to compare those to the diameters of human cerebral brain-supplying arteries in order to assess the validity of the Aachen minipig as a human intracranial in vivo model. We measured the diameters in the external carotid artery and eight different branches of the subclavian artery in 12 Aachen minipigs using angiographic imaging. Analysed arteries comprised the external carotid artery, axillary artery, brachial artery, subscapular artery first segment, subscapular artery second segment, external thoracic artery, caudal circumflex humeral artery, suprascapular artery and thoracodorsal artery. We compared these diameters to diameters of the following human brain-supplying arteries: terminal internal carotid artery (carotid-T and petrous segment), M1 segment of the middle cerebral artery, M2 segments of the middle cerebral artery, anterior cerebral artery, vertebral artery and basilar artery. Median diameters of porcine forelimb arteries ranged from 1.8 to 4.9 mm, and human brain supplying arteries ranged in diameter from 1.4 to 4.3 mm. Depending on the intended use, this allows porcine forelimb arteries to be selected which are statistically comparable to human brain-supplying vessels. In conclusion, we identified several equivalent arteries of the porcine subclavian branches that are comparable to human brain-supplying arteries. This may help to validate the minipig as a suitable in vivo model for neurovascular experiments.

Differences in vasomotor function of mesenteric arteries between Ossabaw minipigs with predisposition to metabolic syndrome and Göttingen minipigs.

Metabolic syndrome predisposes and contributes to the development and progression of atherosclerosis. The minipig strain "Ossabaw" is characterized by a predisposition to develop metabolic syndrome. We compared vasomotor function in Ossabaw minipigs before they developed their diseased phenotype to that of Göttingen minipigs without such genetic predisposition. Mesenteric arteries of adult Ossabaw and Göttingen minipigs were dissected postmortem and mounted on a myograph for isometric force measurements. Maximal vasoconstriction to potassium chloride (KClmax) was induced. Cumulative concentration-response curves were determined in response to norepinephrine. Endothelium-dependent (with carbachol) and endothelium-independent (with nitroprusside) vasodilation were analyzed after preconstriction by norepinephrine. In a bioinformatic analysis, variants/altered base pairs within genes associated with cardiovascular disease were analyzed. KClmax was similar between the minipig strains (15.6 ± 6.7 vs. 14.1 ± 3.4 ΔmN). Vasoconstriction in response to norepinephrine was more pronounced in Ossabaw than in Göttingen minipigs (increase of force to 143 ± 48 vs. 108 ± 38% of KClmax). Endothelium-dependent and endothelium-independent vasodilation were less pronounced in Ossabaw than in Göttingen minipigs (decrease of force to 46.4 ± 29.6 vs. 16.0 ± 18.4% and to 36.7 ± 25.2 vs. 2.3 ± 3.7% of norepinephrine-induced preconstriction). Vasomotor function was not different between the sexes. More altered base pairs/variants were identified in Ossabaw than in Göttingen minipigs for the exon encoding adrenoceptor-α1A. Vasomotor function in lean Ossabaw minipigs is shifted toward vasoconstriction and away from vasodilation in comparison with Göttingen minipigs, suggesting a genetic predisposition for vascular dysfunction and atherosclerosis in Ossabaw minipigs. Thus, Ossabaw minipigs may be a better model for human cardiovascular disease than Göttingen minipigs.NEW & NOTEWORTHY Animal models with a predisposition to metabolic syndrome and atherosclerosis are attracting growing interest for translational research, as they may better mimic the variability of patients with cardiovascular disease. In Ossabaw minipigs, with a polygenic predisposition to metabolic syndrome, but without the diseased phenotype, vasoconstriction is more and vasodilation is less pronounced in mesenteric arteries than in Göttingen minipigs. Ossabaw minipigs may be a more suitable model of human cardiovascular disease.

Minipigs used in hydrogel wound repair research / 中国组织工程研究

BACKGROUND:Minipigs are often used in research fields such as skin injury,vascular trauma and cosmetic medicine because they are highly similar to human beings in terms of skin tissue structure and cardiovascular system.Hydrogel as a wound repair drug possesses a variety of excellent physicochemical properties such as strong water retention and adhesion,which can provide isolation moisturization and drug release for wounds. OBJECTIVE:To summarize and conclude the progress of the application of trauma models for different experimental purposes of hydrogel therapy for minipigs,to reveal the development status of various types of minipig trauma models,to analyze the deficiencies of minipig trauma models at the present stage. METHODS:The relevant articles published in Web of Science database and CNKI database from the establishment of each database to 2023 were checked,using"piglet,miniature pig,minipig,miniature pig;gel,hydrogel;trauma,injury,wound,lesion,incision"as Chinese search terms and"Miniature Swine,Miniature pig,minipig;gel,hydrogel;injury,wound,lesion,incision"as English search terms.A total of 438 Chinese and English documents were retrieved,and 59 documents were included in the study through the inclusion and exclusion criteria. RESULTS AND CONCLUSION:(1)At present,the main models used clinically for trauma repair are large animal species(dogs and pigs),rabbits,and rodents(rats and mice).Because the skin structure of the minipig is more like that of humans,the minipig is the most ideal animal model for trauma repair.(2)In the in-vitro skin injury model,skin defect model is the basic wound model,which can be divided into full skin defect model and medium-thickness skin defect model according to the depth of the wound defect.Burn wound model and infected wound model are multidimensional models with hot metal scald and bacterial culture imposed on the basis of the skin defect model,which have the advantages of high safety coefficient and low operation difficulty.(3)In the in-vivo trauma repair model,mini-pigs are used as esophageal cricothyrotomy model which is more in line with the pathological state of clinical diseases.Mini-pigs are used in the gastric perforation and vascular hemostasis model,which can visually demonstrate the stronger organ adhesion,hemostatic properties and tissue regeneration-promoting effects of the hydrogel.(4)The specific parts of the pig also has the corresponding mode of use:pig ear is usually used to evaluate the hydrogel drug delayed-release effect.Porcine cellular proteins and pig skin collagen are mostly used to prepare composite hydrogels of tissue origin.

Commensal Bacteria Impact on Intestinal Toll-like Receptor Signaling in Salmonella-Challenged Gnotobiotic Piglets.

Gnotobiotic (GN) animals with simple and defined microbiota can help to elucidate host-pathogen interferences. Hysterectomy-derived germ-free (GF) minipigs were associated at 4 and 24 h post-hysterectomy with porcine commensal mucinolytic Bifidobacterium boum RP36 (RP36) strain or non-mucinolytic strain RP37 (RP37) or at 4 h post-hysterectomy with Lactobacillus amylovorus (LA). One-week-old GN minipigs were infected with Salmonella Typhimurium LT2 strain (LT2). We monitored histological changes in the ileum, mRNA expression of Toll-like receptors (TLRs) 2, 4, and 9 and their related molecules lipopolysaccharide-binding protein (LBP), coreceptors MD-2 and CD14, adaptor proteins MyD88 and TRIF, and receptor for advanced glycation end products (RAGE) in the ileum and colon. LT2 significantly induced expression of TLR2, TLR4, MyD88, LBP, MD-2, and CD14 in the ileum and TLR4, MyD88, TRIF, LBP, and CD14 in the colon. The LT2 infection also significantly increased plasmatic levels of inflammatory markers interleukin (IL)-6 and IL-12/23p40. The previous colonization with RP37 alleviated damage of the ileum caused by the Salmonella infection, and RP37 and LA downregulated plasmatic levels of IL-6. A defined oligo-microbiota composed of bacterial species with selected properties should probably be more effective in downregulating inflammatory response than single bacteria.

Characteristics of Metabolites in the Development of Atherosclerosis in Tibetan Minipigs Determined Using Untargeted Metabolomics.

BACKGROUND: Atherosclerosis (AS) is a chronic progressive disease caused by lipometabolic disorder. However, the pathological characteristics and mechanism of AS have not been fully clarified. Through high-fat and high-cholesterol diet induction, Tibetan minipigs can be used as the AS model animals, as they have a very similar AS pathogenesis to humans. METHODS: In this study, we built an AS model of Tibetan minipigs and identified the differential abundance metabolites in the development of AS based on untargeted metabolomics. RESULTS: We found that sphingolipid metabolism and glucose oxidation were obviously higher in the AS group and phenylalanine metabolism was reduced in the AS group. Moreover, in the development of AS, gluconolactone was enriched in the late stage of AS whereas biopterin was enriched in the early stage of AS. CONCLUSIONS: Our research provides novel clues to investigate the metabolic mechanism of AS from the perspective of metabolomics.