Minipig Model Research Articles

Mitochondrial Dysfunction in a High Intraocular Pressure-Induced Retinal Ischemia Minipig Model.

Purpose: Retinal ischemia (RI) and progressive neuronal death are sight-threatening conditions. Mitochondrial (mt) dysfunction and fusion/fission processes have been suggested to play a role in the pathophysiology of RI. This study focuses on changes in the mt parameters of the neuroretina, retinal pigment epithelium (RPE) and choroid in a porcine high intraocular pressure (IOP)-induced RI minipig model. Methods: In one eye, an acute IOP elevation was induced in minipigs and compared to the other control eye. Activity and amount of respiratory chain complexes (RCC) were analyzed by spectrophotometry and Western blot, respectively. The coenzyme Q10 (CoQ10) content was measured using HPLC, and the ultrastructure of the mt was studied via transmission electron microscopy. The expression of selected mt-pathway genes was determined by RT-PCR. Results: At a functional level, increased RCC I activity and decreased total CoQ10 content were found in RPE cells. At a protein level, CORE2, a subunit of RCC III, and DRP1, was significantly decreased in the neuroretina. Drp1 and Opa1, protein-encoding genes responsible for mt quality control, were decreased in most of the samples from the RPE and neuroretina. Conclusions: The eyes of the minipig can be considered a potential RI model to study mt dysfunction in this disease. Strategies targeting mt protection may provide a promising way to delay the acute damage and onset of RI.

Acute Effects of Different Electroacupuncture Point Combinations to Modulate the Gut-Brain Axis in the Minipig Model.

This study aimed to compare the gut-brain axis responses to acute electroacupuncture (EA) at different acupoint combinations in the minipig model. Four adult Yucatan minipigs were subjected twice to four acute EA treatments (25-minute acute sessions) including sham (false acupoints) and control (no EA), during anesthesia and according to a Latin-square design paradigm. Acupoint combinations (4 loci each) are head-abdomen (#70 Dafengmen, #35 Sanwan), back (bilateral #27 Pishu, #28 Weishu), leg (bilateral #79 Hangou, #63 Housanli), and sham (2 bilateral points that are not acupoints). Electrocardiograms were performed to explore heart rate variability (HRV). Infrared thermography was used to measure skin temperature at the stimulation points. Saliva (cortisol) and blood samples (leptin, total/active ghrelin, insulin, and glucose) were collected for further analyses before and after acute EA. All animals were also subjected to BOLD fMRI to investigate the brain responses to EA. Acute EA significantly modulated several physiological and metabolic parameters compared to basal, sham, and/or control conditions, with contrasting effects in terms of BOLD responses in brain regions involved in the hedonic and cognitive control of food intake. The head-abdomen combination appeared to be the most promising combination in terms of brain modulation of the corticostriatal circuit, with upregulation of the dorsolateral prefrontal cortex, dorsal striatum, and anterior cingulate cortex. It also induced significantly lower plasma ghrelin levels compared to sham, suggesting anorectic effects, as well as no temperature drop at the stimulation site. This study opens the way to a further preclinical trial aimed at investigating chronic EA in obese minipigs.

Key factors to establish the ovalbumin-induced atopic dermatitis minipig model: age and body weight

BackgroundGiven its similar structure and immune response to the human skin, porcine is a good model for dermal studies. Here, we sensitized ovalbumin (Ova) on minipig back skin for 2–4 weeks to induce chronic atopic dermatitis (AD).ResultsGross observation, serum cytokine level, epidermal thickness, and epidermal integrity did not change after 4 weeks of Ova induction compared with the control, indicating AD modeling failure. Only the neutrophils in the blood and macrophages in bronchoalveolar lavage fluid changed slightly until 3 or 2 weeks after Ova sensitization, respectively. The successful and failed Ova-induced AD minipig models only differ in age and body weight of the minipigs. The minipigs, 12 months old with a 30-kg median weight, had a two-fold thicker dermis than minipigs 8–10 months old, with an 18.97-kg median weight, resulting in impaired Ova permeability and immune response.ConclusionAge and body weight are key factors that should be considered when developing an Ova-induced AD minipig model.

Autologous Genetically Enriched Leucoconcentrate in the Preventive and Acute Phases of Stroke Treatment in a Mini-Pig Model

The natural limitations of regeneration in the CNS are major problems for the treatment of neurological disorders, including ischaemic brain strokes. Among the approaches being actively developed to inhibit post-ischaemic negative consequences is the delivery of therapeutic genes encoding neuroprotective molecules to the brain. Unfortunately, there are currently no proven and available medicines that contain recombinant human genes for the treatment of ischaemic cerebral stroke. Of particular interest is the development of treatments for patients at risk of ischaemic stroke. In the present study, we propose a proof of concept for the use of an autologous, genetically enriched leucoconcentrate temporally secreting recombinant vascular endothelial growth factor (VEGF), glial-cell-line-derived neurotrophic factor (GDNF) and the neural cell adhesion molecule (NCAM) for the treatment of stroke. In a mini-pig ischaemic stroke model, genetically enriched leucoconcentrate was infused 4 h after surgery (gene therapy in acute phase) or 2 days before stroke modelling (preventive gene therapy). On day 21, after the stroke modelling, the post-ischaemic brain recovery was examined by morphologic and immunofluorescence analysis. The benefits of treating a stroke with genetically enriched leucoconcentrate both for preventive purposes and in the acute phase were confirmed by an improved performance in behavioural tests, higher preservation of brain tissue and positive post-ischaemic brain remodelling in the peri-infarct area. These results suggest that the employment of autologous leucocytes enabling the temporary production of the recombinant therapeutic molecules to correct the pathological process in the CNS may be one of the breakthrough approaches in gene therapy.

Chinese medicine Fufang Zhenzhu Tiaozhi capsule ameliorates coronary atherosclerosis in diabetes mellitus-related coronary heart disease minipigs

BackgroundDiabetes mellitus-related coronary heart disease (DM-CHD) is the most common cause of death in diabetic patients. Various studies have shown that Chinese medicine Fufang-Zhenzhu-Tiaozhi capsule (FTZ) has therapeutic effects on cardiovascular diseases. More research is required to determine the mechanism of FTZ protection against coronary atherosclerosis. ObjectiveTo investigate the unique mechanism of FTZ in treatment of DM-CHD minipigs with coronary atherosclerosis. MethodsHigh-fat/high-sucrose/high-cholesterol diet combined with streptozotocin and coronary balloon injury were used to induce DM-CHD minipig model, which was then randomly divided into: DM-CHD model, DM-CHD treated with FTZ or positive drug (Metformin + Atorvastatin, M+A). After twenty-two weeks, ultrasonography, electrocardiography, and image detection were employed to detect cardiac functions and assess coronary artery stenosis and plaque. Human umbilical vein endothelial cells (HUVECs) were treated high glucose or/and FTZ. Pigs tissues and treated-cells were collected for further testing. ResultsIn DM-CHD minipigs, FTZ treatment significantly reduced disordered glycolipid metabolism similar as M+A administration. FTZ and M+A also alleviated coronary stenosis and myocardial injury. In addition, IκB and NF-κB phosphorylation levels, as well as the protein levels of IL-1β, Bax, cleave-Caspase 3, Bcl-2, and α-SMA were dramatically increased in the DM-CHD coronary artery, whereas CD31 and VE-cadherin expressions were decreased. Similar to M+A, FTZ reversed these protein levels in the DM-CHD coronary artery. Furthermore, FTZ ameliorated the damage and high migration activity of HUVECs induced by high glucose. ConclusionsFTZ improves coronary atherosclerosis through modulating inflammation, alleviating apoptosis, and inhibiting EndMT of coronary artery to protects against DM-CHD.

339 Relationships of Jugular Bulb Parameters Used as Indicators of Cerebral Perfusion and Metabolism With Cerebral Perfusion and Metabolism After Resuscitation from Cardiac Arrest: A Post-hoc Analysis of Experimental Studies Using a Minipig Model

339 Relationships of Jugular Bulb Parameters Used as Indicators of Cerebral Perfusion and Metabolism With Cerebral Perfusion and Metabolism After Resuscitation from Cardiac Arrest: A Post-hoc Analysis of Experimental Studies Using a Minipig Model

S1566 Evaluation of the Pharmacokinetics of PGN-OB1 Following Oral Administration of an Oral Biotherapeutics Delivery System (OBDS) in Yucatan Swine

Introduction: Biologics/peptides/nucleic acids are highly effective drugs; however, oral delivery of these therapeutics has proved to be difficult due to the harsh conditions of the upper gastrointestinal tract (GIT) and the poor absorption rate in the small intestinal mucosa. We aimed to develop an oral biotherapeutic delivery system (OBDS) that protects these biomolecules from degradation in the upper GIT and increases oral bioavailability via needless injection in the submucosal space of the small intestine. We describe the development of models to assess the functional capability of the OBDS capsule. A Yucatan minipig model was chosen to better represent the pharmacokinetic properties of submucosal injection in humans and evaluate the injection efficiency of OBDS in vivo. Methods: Due to prolonged and variable gastric residence times in the swine model, the semi-autonomous OBDS capsules containing a variant of adalimumab (PGN-001), PGN-OB1, were administrated by intraduodenal endoscopic placement (ID) and released into the proximal small intestines of the female Yucatan swine. Blood samples post-ID dosing were collected to evaluate the injection efficiency of the OBDS compared with the IV control group. Results: All OBDS capsules were successfully advanced through the pyloric sphincter via endoscopic placement, without early deployment, and released in the proximal duodenum to naturally transit and deploy in vivo. Out of 13 animals dosed, 8 animals showed detectable drug levels (Figure), and an oral bioavailability average of 22% or 25% (range from 7-55%) excluding an animal showing a late deployment at 72hr post-dose. The variability in the swine model is believed to be due to physiologic variability that may not directly translate to humans including variability in small intestinal transit time, and more frequent and larger, gas and fluid pockets in the swine. Conclusion: Here we have provided proof-of-concept of a semi-autonomous OBDS device that can achieve as high as 55% bioavailability of a variant of adalimumab that is a magnitude higher than current oral protein or peptide delivery technology in the market and at levels much closer to the subcutaneous route of administration estimated in human trials. The OBDS capsules could potentially provide a better alternative for the non-invasive route of administration with better patient compliance.Figure 1.: Plasma concentration of PGN-001 treated with ID and IV over time

A humanized minipig model for the toxicological testing of therapeutic recombinant antibodies

The safety of most human recombinant proteins can be evaluated in transgenic mice tolerant to specific human proteins. However, owing to insufficient genetic diversity and to fundamental differences in immune mechanisms, small-animal models of human diseases are often unsuitable for immunogenicity testing and for predicting adverse outcomes in human patients. Most human therapeutic antibodies trigger xenogeneic responses in wild-type animals and thus rapid clearance of the drugs, which makes in vivo toxicological testing of human antibodies challenging. Here we report the generation of Göttingen minipigs carrying a mini-repertoire of human genes for the immunoglobulin heavy chains γ1 and γ4 and the immunoglobulin light chain κ. In line with observations in human patients, the genetically modified minipigs tolerated the clinically non-immunogenic IgG1κ-isotype monoclonal antibodies daratumumab and bevacizumab, and elicited antibodies against the checkpoint inhibitor atezolizumab and the engineered interleukin cergutuzumab amunaleukin. The humanized minipigs can facilitate the safety and efficacy testing of therapeutic antibodies.

α2-macroglobulin-rich serum as a master inhibitor of inflammatory factors attenuates cartilage degeneration in a mini pig model of osteoarthritis induced by "idealized" anterior cruciate ligament reconstruction.

Post-traumatic osteoarthritis is a special type of osteoarthritis and a common disease, with few effective treatments available. α2-Macroglobulin (α2M) is important to chondral protection in post-traumatic osteoarthritis. However, its injection into xenogeneic joint cavities involves safety hazards, limiting clinical applications. Exploring serum α2M-enriching strategies and the therapeutic effect and mechanism of α2M-rich serum (α2MRS) autologous joint injection to treat post-traumatic osteoarthritis has significant value. In the present study, a unique filtration process was used to obtain α2MRS from human and mini pig serum. We evaluated the potential of α2MRS in protecting against post-surgery cartilage degeneration. We identify the potential of α2MRS in reducing the expression of inflammatory cytokines and factors that hasten cartilage degeneration in post-operative conditions leading to post-traumatic osteoarthritis. The potential of α2MRS was analyzed in interleukin-1β induced human chondrocytes and mini pig models. In the chondrocyte model, α2MRS significantly promoted human chondrocyte proliferation and reduced apoptosis and chondrocyte catabolic cytokine gene transcription and secretion. The anterior cruciate ligament autograft reconstruction model of mini pigs was randomized into groups, operated on, and injected with α2MRS or saline. The results showed that α2MRS injection significantly suppressed the levels of inflammatory factors, improved gait, and showed significantly lower cartilage degeneration than the groups that did not receive α2MRS injections. This study highlights the chondroprotective effects of α2MRS, elucidated its potential applications against cartilage degeneration, and could provide a basis for the clinical translation of α2MRS.

A genetically modified minipig model for Alzheimer’s disease with SORL1 haploinsufficiency

SummaryThe established causal genes in Alzheimer’s disease (AD), APP, PSEN1, and PSEN2, are functionally characterized using biomarkers, capturing an in vivo profile reflecting the disease’s initial preclinical phase. Mutations in SORL1, encoding the endosome recycling receptor SORLA, are found in 2%–3% of individuals with early-onset AD, and SORL1 haploinsufficiency appears to be causal for AD. To test whether SORL1 can function as an AD causal gene, we use CRISPR-Cas9-based gene editing to develop a model of SORL1 haploinsufficiency in Göttingen minipigs, taking advantage of porcine models for biomarker investigations. SORL1 haploinsufficiency in young adult minipigs is found to phenocopy the preclinical in vivo profile of AD observed with APP, PSEN1, and PSEN2, resulting in elevated levels of β-amyloid (Aβ) and tau preceding amyloid plaque formation and neurodegeneration, as observed in humans. Our study provides functional support for the theory that SORL1 haploinsufficiency leads to endosome cytopathology with biofluid hallmarks of autosomal dominant AD.

Tacrolimus before CTLA4Ig and rapamycin promotes vascularized composite allograft survival in MGH miniature swine

BackgroundWe evaluated the outcome of vertical rectus abdominus myocutaneous flap (VRAM) allotransplantation in a mini-pig model, using a combined co-stimulation blockade (Co-SB) and mechanistic target of rapamycin inhibition (mTORi)-based regimen, with or without preceding calcineurin inhibition (CNI). Materials and methodsVRAM allotransplants were performed between SLA-mismatched MGH miniature swine. Group A (n = 2) was treated continuously with the mTOR inhibitor rapamycin from day −1 in combination with the Co-SB agent cytotoxic T lymphocyte antigen 4-Ig (CTLA4-Ig) from post-operative day (POD) 0. In group B (n = 3), animals received tacrolimus daily from POD 0 to POD 13, followed by rapamycin daily from POD 7 and CTLA4-Ig weekly from POD 7–28. Graft rejection was determined by Banff criteria and host cellular and humoral immunity monitored. ResultsIn group A, allografts developed grade-I acute rejection by POD 2 and POD 7, and reached grade-IV by POD 17 and POD 20, respectively. By contrast, in group B, two allografts demonstrated grade-I rejection on POD 30 and grade-IV on POD 74, while the third exhibited grade-I rejection starting on POD 50, though this animal had to be euthanized on POD 58 due to Pneumocystis jirovecii infection. Time-to-event incidence of grade-I rejection was significantly lower in group A compared to group B. During the first 3 weeks post-transplant, no significant differences in anti-donor immunity were observed between the groups. ConclusionA short course of CNI, followed by combined Co-SB and mTORi significantly delays acute rejection of VRAM allografts in SLA-mismatched miniature swine.

The Yucatan minipig model: A new preclinical model of malnutrition induced by a low-calorie/low-protein diet

Severe malnutrition exposes patients to adverse outcomes and a higher mortality risk. The Yucatan minipig, closer to human physiology than murine models could be a pertinent and innovative experimental model for studying the physiopathology and consequences of severe malnutrition. The present study aimed to determine whether a low calorie/low protein diet (LC/LP) can reproduce marasmus malnutrition in minipigs, and to characterize body composition, gut microbiota, malnutrition-related blood parameters, and histological and molecular skeletal muscle patterns. Eleven Yucatan minipigs were subjected to two different diets: a standard control diet (ST) (n=5) and a LC/LP diet (n=6). LC/LP animals daily received 50% of an isocaloric low-protein diet (10.37MJ/kg, 8.6% protein). Body composition was measured by computed tomography (CT-scan) before (T0) and after 8 weeks of diet (T8). Trapezius and biceps femoris muscles were sampled at the end of protocol to perform histological and molecular analyses. Gut microbiota composition were was also analyzed at T0 and T8 in fecal samples. Eight weeks of LC/LP diet significantly reduced body weight (-12.3±9.5%, P=0.03) and gut microbiota richness (i.e. number of observed species) (-10.4±8.3%, P=0.014) compared to baseline. After 8 weeks, LC/LP animals exhibited a significant reduction of retroperitoneal fat and skeletal muscle surface areas (P=0.03 and P=0.047, respectively), whereas these parameters remained unchanged in ST animals. These reductions were associated with lower muscle fiber cross-sectional area (CSA) in trapezius (P<0.001) and biceps femoris (P=0.003) in LC/LP animals compared to ST. LC/LP diet promoted an increase of AMP kinase phosphorylation in trapezius and biceps femoris (P=0.05), but did not affect cytochrome c and COX IV protein content, markers of mitochondrial content. Gene and proteins involved in ubiquitin-proteasome system and apoptosis remained unchanged after 8 weeks of LC/LP diet both in trapezius and biceps femoris. All these findings support that this experimental minipig model of severe malnutrition is valid to mimic pathophysiological changes occurring in human protein-energy marasmus malnutrition and muscle atrophy associated with malnutrition, as observed in patients with secondary sarcopenia.

Quantitative assessment of motor function in minipig models of neurological disorders using a pressure-sensitive gait mat

• A pressure sensitive gait mat is a useful tool for quantitative motor assessment. • Pressure sensitive gait mats are simple alternatives to camera-sensor based systems. • The gait of minipigs displays symmetry and a slightly frontal center of gravity. • Subtle motor deterioration is detectable after lesions affecting the motor system. • Lesion-compensatory dynamics involve decreased velocity and increased stance time.

Magnesium stable isotope composition, but not concentration, responds to obesity and early insulin-resistant conditions in minipig

Hypomagnesemia is frequently associated with type 2 diabetes and generally correlates with unfavorable disease progression, but the magnesium status in pre-diabetic conditions remains unclear. Here, the magnesium metabolism is scrutinized in a minipig model of obesity and insulin resistance by measuring variations of the metallome—the set of inorganic elements—and the magnesium stable isotope composition in six organs of lean and obese minipigs raised on normal and Western-type diet, respectively. We found that metallomic variations are most generally insensitive to lean or obese phenotypes. The magnesium stable isotope composition of plasma, liver, kidney, and heart in lean minipigs are significantly heavier than in obese minipigs. For both lean and obese minipigs, the magnesium isotope composition of plasma and liver were negatively correlated to clinical phenotypes and plasma lipoproteins concentration as well as positively correlated to hyperinsulinemic-euglycemic clamp output. Because the magnesium isotope composition was not associated to insulin secretion, our results suggest that it is rather sensitive to whole body insulin sensitivity, opening perspectives to better comprehend the onset of insulin-resistant diabetic conditions.

Establishment of Mini-pig Model of Ureteral Stricture by Electrocoagulation Under Ureteroscopy

To establish a mini-pig model of ureteral stricture by using electrocoagulation under ureteroscopy. Twelve female mini-pigs were included. Their ureters on one side and contralateral side were randomly divided into electrocoagulation and control groups, respectively. In the electrocoagulation group, the middle ureter was circumferentially electrocoagulated by using a self-made electrocoagulation device with the ureteroscope under direct vision, while the control group underwent ureteroscopy only without electrocoagulation. At 30 and 90 days after electrocoagulation, the glomerular filtration rate (GFR), formation of ureteral stricture, and histomorphological changes of ureteral tissues of each group were detected. At 90 days after surgery, ureteroscopy and retrograde urography revealed ureteral stricture formation in the middle ureter in the electrocoagulation group. GFR was gradually decreased over time with prolonged washout half-time in the electrocoagulation group. A compensatory increase in GFR was observed in the control group. Hematoxylin and eosin staining and Masson's Trichrome staining revealed fibroblast infiltration and fibrous tissue hyperplasia in the superficial muscular layers, and the muscular layers were arranged disorderly in the electrocoagulation group. Immunohistochemical staining showed accumulation and disorganization of ureteric epithelium in the narrow segment. In the control group, the epithelium was arranged neatly with normal structure. A mini-pig model of ureteral stricture was successfully established using electrocoagulation under ureteroscopy. This method has the advantages of being simple to implement, having high accuracy and high success rate, which can provide an ideal animal model for studying ureteral stricture.

Bone Response to Osteopontin-Functionalized Carboxyethylphosphonic Acid-Modified Implants. Experimental Study in a Minipig Model

Currently, dental implants have become a common and reliable treatment for restoring masticatory function in edentulous patients. Their surface topography is of great importance for the adhesion and remodeling of bone cells, both in the initial phases and over time, and different strategies have been proposed to improve the biological performance of conventional sandblasted, large-grit, acid-etched implant surfaces. Corrosion has been identified as one of the causes of implant failure due to contact with oral fluids. Carboxyethylphosphonic acid is a potent anticorrosive that would form stable bonds with titanium oxide, generating an organic layer on which modifications could be made to improve cell adhesion. Osteopontin is considered a molecule capable of improving the osseointegration of titanium. Our study evaluated the osseointegration capacity of titanium implants modified with carboxyethylphosphonic acid and functionalized with osteopontin in a minipig model. A total of 16 implants were inserted in the tibial diaphysis of two minipigs, 8 implants modified with carboxyethylphosphonic acid and functionalized with osteopontin from the experimental group and 8 from the control group with sandblasted, large-grit, acid-etched surface treatment. After 4 weeks, the animals were sacrificed and the samples were analyzed by histomorphometric analysis, assessing bone-implant contact, cortical bone-implant contact, percentage of new bone, peri-implant bone density and interthread bone area interthread. Statistical analysis was performed using SPSS v.18. Statistical significance was found between groups for the percentage of new bone (p = 0.04) and for interthread bone area interthread (p = 0.01). Functionalization of titanium surfaces by osteopontin may be of interest for conditioning bone remodeling in the early stages of osseointegration, although more in vivo studies are needed to determine its real influence in this aspect.

The Effects of Abutment Materials on Peri-Implant Soft Tissue Integration: A Study in Minipigs.

To evaluate, in a minipig model, the soft tissue integration of four different transmucosal materials, as well as the peri-implant bone remodeling. A total of 40 implants were placed in five minipigs in a single stage surgery, and two of each of the following abutment materials were used in each animal: (1) titanium (Ti; control), (2) polymethylmethacrylate (PMMA), (3) zirconia (Zi), and (4) veneering ceramic (VC). After a healing period of 3 months, the samples were collected and subjected to nondecalcified histology. The soft tissue dimensions (sulcus, junctional epithelium, and connective tissue attachment) were assessed on each abutment and the distance from the implant margin to first bone-to-implant contact (BIC) was measured. The mean biological width-characterized by the sum of junctional epithelium and connective tissue measurements-was 3.8 (0.6) mm and no statistically significant difference was found between the four groups (p = 0.41). However, a long junctional epithelium (3.3-3.8 mm) and a very short connective tissue attachment (0.1-0.2 mm) were observed with all abutments. The measured peri-implant bone remodeling was similar in all four groups (p = 0.88). Within its limitations, this study showed that all tested materials allowed soft tissue integration, consisting of a long junctional epithelium, extending close to the bone level, and a rather short portion of connective tissue.

Multiscale analysis of craniomaxillofacial bone repair: A preclinical mini-pig study.

The rate of reparative osteogenesis controls when an implant is sufficiently stable as to allow functional loading. Using a mini pig model, the rate of reparative osteogenesis in two types of implant sites for example, an osteotomy versus a fresh extraction socket were compared. Eight adult mini pigs were used for the study. In phase I, three premolars were extracted on one side of the oral cavity; 12weeks later, in phase II, osteotomies were produced in healed extraction sites, and contralateral premolars were extracted. Animals were sacrificed 1, 5, and 12weeks after phase II. Bone repair and remodeling were evaluated using quantitative micro-computed tomographic imaging, histology, and histochemical assays coupled with quantitative dynamic histomorphometry. One week after surgery, extraction sockets and osteotomy sites exhibited similar patterns of new bone deposition. Five weeks after surgery, mineral apposition rates (MARs) were elevated at the injury sites relative to intact bone. Twelve weeks after surgery, the density of new bone in both injury sites was equivalent to intact bone but quantitative dynamic histomorphometry and cellular activity assays demonstrated bone remodeling was still underway. The mechanisms and rates of reparative osteogenesis were equivalent between fresh extraction sockets and osteotomies. The volume of new bone required to fill a socket, however, was significantly greater than the volume required to fill an osteotomy. These data provide a framework for estimating the rate of reparative osteogenesis and the time to loading of implants placed in healed sites versus fresh extraction sockets.

Role of NOD-Like Receptors in a Miniature Pig Model of Diabetic Renal Injuries.

Activation of NOD-like receptor (NLR) signaling pathway can promote downstream cytokine and proinflammatory cytokines release, and inflammation induced by excess nutrients leads to renal metabolic injury. How the NLRs influence metabolic progress and then lead to the renal injury remains poorly investigated. Compared with rodents, minipigs are more similar to humans and are more ideal animal models for human disease research. In this study, we established a diabetic minipig model through a high-sugar and high-fat diet combined with streptozotocin (STZ) injection. Blood biological markers and renal pathological markers, expression of NLRP subfamily members (NLRP1 and NLRP3) and their downstream cytokines (precursors of IL-1β and IL-18 and mature forms of IL-1β and IL-18), expression of NLRC subfamily members (NLRC1, NLRC2, and NLRC5) and their downstream nuclear factor-κB (NF-κB) signaling pathway molecules (IKKβ, IκBα, and NF-κB p65), and inflammatory cytokines (TNF-α and interleukin-6 (IL-6)) were systematically evaluated. The expression of NLRP3 and its downstream cytokine signaling molecules, the precursors of IL-1β and IL-18, and the mature forms of IL-1β and IL-18 was significantly upregulated. The expression levels of NLRC1, NLRC2, and NLRC5 and activation of the downstream NF-κB pathway molecules phospho-IKKβ, phospho-IκBα, NF-κB p65, and phospho-NF-κB p65 were significantly increased. The TNF-α and IL-6 levels were significantly increased in diabetic pig kidneys. The TGF-β/Smad signaling molecules, TGF-β and P-SMAD2/3, were also increased. These results suggested that the metabolic inflammation activated by NLRs might play an important role in diabetic renal injuries.

Human Muse cells reduce myocardial infarct size and improve cardiac function without causing arrythmias in a swine model of acute myocardial infarction.

We recently reported that multilineage-differentiating stress enduring (Muse) cells intravenously administered after acute myocardial infarction (AMI), selectively engrafted to the infarct area, spontaneously differentiated into cardiomyocytes and vessels, reduced the infarct size, improved the left ventricular (LV) function and remodeling in rabbits. We aimed to clarify the efficiency of Muse cells in a larger animal AMI model of mini-pigs using a semi-clinical grade human Muse cell product. Mini-pigs underwent 30 min of coronary artery occlusion followed by 2 weeks of reperfusion. Semi-clinical grade human Muse cell product (1x107, Muse group, n = 5) or saline (Vehicle group, n = 7) were intravenously administered at 24 h after reperfusion. The infarct size, LV function and remodeling were evaluated by echocardiography. Arrhythmias were evaluated by an implantable loop recorder. The infarct size was significantly smaller in the Muse group (10.5±3.3%) than in the Vehicle group (21.0±2.0%). Both the LV ejection fraction and fractional shortening were significantly greater in the Muse group than in the Vehicle group. The LV end-systolic and end-diastolic dimensions were significantly smaller in the Muse group than in the Vehicle group. Human Muse cells homed into the infarct border area and expressed cardiac troponin I and vascular endothelial CD31. No arrhythmias and no blood test abnormality were observed. Muse cell product might be promising for AMI therapy based on the efficiency and safety in a mini-pig AMI.