Material Design of Porous Hydroxyapatite Ceramics via Inverse Analysis of an Estimation Model for Bone-Forming Ability Based on Machine Learning and Experimental Validation of Biological Hard Tissue Responses

Hydroxyapatite and β-tricalcium phosphate have been clinically applied as artificial bone materials due to their high biocompatibility. The development of artificial bones requires the verification of safety and efficacy through animal experiments; however, from the viewpoint of animal welfare, it is necessary to reduce the number of animal experiments. In this study, we utilized machine learning to construct a model that estimates the bone-forming ability of bioceramics from material fabrication conditions, material properties, and in vivo experimental conditions. We succeeded in constructing two models: 'Model 1', which predicts material properties from their fabrication conditions, and 'Model 2', which predicts the bone-formation rate from material properties and in vivo experimental conditions. The inclusion of full width at half maximum (FWHM) in the feature of Model 2 showed an improvement in accuracy. Furthermore, the results of the feature importance showed that the FWHMs were the most important. By an inverse analysis of the two models, we proposed candidates for material fabrication conditions to achieve target values of the bone-formation rate. Under the proposed conditions, the material properties of the fabricated material were consistent with the estimated material properties. Furthermore, a comparison between bone-formation rates after 12 weeks of implantation in the porcine tibia and the estimated bone-formation rate. This result showed that the actual bone-formation rates existed within the error range of the estimated bone-formation rates, indicating that machine learning consistently predicts the results of animal experiments using material fabrication conditions. We believe that these findings will lead to the establishment of alternative animal experiments to replace animal experiments in the development of artificial bones.

Phenotypic features of genetically modified DMD-XKOXWT pigs

Introduction

Duchenne muscular dystrophy (DMD) is a hereditary neuromuscular disorder caused by mutation in the dystrophin gene (DMD) on the X chromosome. Female DMD carriers occasionally exhibit symptoms such as muscle weakness and heart failure. Here, we investigated the characteristics and representativeness of female DMD carrier (DMD-XKOXWT) pigs as a suitable disease model.

Methods

In vitro fertilization using sperm from a DMD-XKOY↔XWTXWT chimeric boar yielded DMD-XKOXWT females, which were used to generate F2 and F3 progeny, including DMD-XKOXWT females. F1-F3 piglets were genotyped and subjected to biochemical analysis for blood creatine kinase (CK), aspartate aminotransferase, and lactate dehydrogenase. Skeletal muscle and myocardial tissue were analyzed for the expression of dystrophin and utrophin, as well as for lymphocyte and macrophage infiltration.

Results

DMD-XKOXWT pigs exhibited various characteristics common to human DMD carrier patients, namely, asymptomatic hyperCKemia, dystrophin expression patterns in the skeletal and cardiac muscles, histopathological features of skeletal muscle degeneration, myocardial lesions in adulthood, and sporadic death. Pathological abnormalities observed in the skeletal muscles in DMD-XKOXWT pigs point to a frequent incidence of pathological abnormalities in the musculoskeletal tissues of latent DMD carriers. Our findings suggest a higher risk of myocardial abnormalities in DMD carrier women than previously believed.

Conclusions

We demonstrated that DMD-XKOXWT pigs could serve as a suitable large animal model for understanding the pathogenic mechanism in DMD carriers and developing therapies for female DMD carriers.

Transplantation of human cells into Interleukin-2 receptor gamma gene knockout pigs under several conditions

Introduction

Previously, we performed gene knockout (KO) of interleukin-2 receptor gamma (IL2RG) in porcine fetal fibroblasts using zinc finger nuclease-encoding mRNAs, subsequently generating IL2RG KO pigs using these cells through somatic cell nuclear transfer. The IL2RG KO pigs lacked a thymus and were deficient in T lymphocytes and natural killer cells, similar to human X-linked severe combined immunodeficiency (SCID) patients. The present study aimed to evaluate whether pigs can support the growth of xenografted human cells and have the potential to be an effective animal model.

Methods

The IL2RG X^KOY pigs used in this study were obtained by mating IL2RG X^KOX females with wild-type boars. This permitted the routine production of IL2RG KO pigs via natural breeding without complicated somatic cell cloning procedures; therefore, a sufficient number of pigs could be prepared. We transplanted human HeLa S3 cells expressing the tandem dimer tomato into the ears and pancreas of IL2RG KO pigs. Additionally, a newly developed method for the aseptic rearing of SCID pigs was used in case of necessity.

Results

Tumors from the transplanted cells quickly developed in all pigs and were verified by histology and immunohistochemistry. We also transplanted these cells into the pancreas of designated pathogen-free pigs housed in novel biocontainment facilities, and large tumors were confirmed.

Conclusions

IL2RG KO pigs have the potential to become useful animal models in a variety of translational biology fields.

•

The present study aimed to evaluate whether IL2RG KO SCID-like pigs can host and support the growth of xenografted human cells under several conditions.

•

Tumors from transplanted cells quickly developed in all pigs, as verified by histology and immunohistochemistry.

•

IL2RG KO pigs have the potential to become extremely useful animal models in a variety of translational biology fields.

Bioresorbable porous β-tricalcium phosphate chelate-setting cements with poly(lactic-co-glycolic acid) particles as pore-forming agent: fabrication, material properties, cytotoxicity, and in vivo evaluation

Calcium-phosphate cements (CPCs) have been used as bone filling materials in orthopaedic surgery. However, CPCs are set using an acid-base reaction, and then change into stable hydroxyapatite (HAp) in a living body. Therefore, we developed bioresorbable chelate-setting β-tricalcium phosphate (β-TCP) cements based on surface modifications of inositol phosphate (IP6). In order to improve the bioresorbability, we fabricated IP6/β-TCP cements hybridized with poly(lactic-co-glycolic acid) (PLGA) particles as a pore-forming agent. The compressive strengths of the cements with the amounts of 5 and 10 mass% PLGA particles were 23.2 and 22.8 MPa, respectively. There was no significant difference from cements without PLGA (23.4 MPa). The setting times of the cement specimens with PLGA particles (30 min) were a little longer than those without PLGA particles (26.3 min). The lack of cytotoxicity of the cement specimens was confirmed using osteoblast-like cells (MC3T3-E1). Cylindrical defects were made by drilling into the tibia of mini-pigs and injecting the prepared cement pastes into the defects. Twelve weeks after implantation the specimens were stained with toluidine blue and histologically evaluated. Histological evaluation of cement specimens with PLGA particles showed enhanced bioresorbability. Newly-formed bone was also observed inside cement specimens with PLGA particles. The IP6/β-TCP cement specimens with PLGA particles had excellent material properties, such as injectability, compressive strength, high porosity, no cytotoxicity in vitro, bioresorption and bone formation abilities in vivo. Organic-inorganic hybridized CPCs are expected to be valuable as novel biodegradable paste-like artificial bone fillers.

Feasibility of large experimental animal models in testing novel therapeutic strategies for diabetes

Diabetes is among the top 10 causes of death in adults and caused approximately four million deaths worldwide in 2017. The incidence and prevalence of diabetes is predicted to increase. To alleviate this potentially severe situation, safer and more effective therapeutics are urgently required. Mice have long been the mainstay as preclinical models for basic research on diabetes, although they are not ideally suited for translating basic knowledge into clinical applications. To validate and optimize novel therapeutics for safe application in humans, an appropriate large animal model is needed. Large animals, especially pigs, are well suited for biomedical research and share many similarities with humans, including body size, anatomical features, physiology, and pathophysiology. Moreover, pigs already play an important role in translational studies, including clinical trials for xenotransplantation. Progress in genetic engineering over the past few decades has facilitated the development of transgenic animals, including porcine models of diabetes. This article discusses features that attest to the attractiveness of genetically modified porcine models of diabetes for testing novel treatment strategies using recent technical advances.

Genetically engineered pigs manifesting pancreatic agenesis with severe diabetes

INTRODUCTION

Pancreatic duodenum homeobox 1 (Pdx1) expression is crucial for pancreatic organogenesis and is a key regulator of insulin gene expression. Hairy and enhancer of split 1 (Hes1) controls tissue morphogenesis by maintaining undifferentiated cells. Hes1 encodes a basic helix loop helix (bHLH) transcriptional repressor and functionally antagonizes positive bHLH genes, such as the endocrine determination gene neurogenin-3. Here, we generated a new pig model for diabetes by genetic engineering Pdx1 and Hes1 genes.

RESEARCH DESIGN AND METHODS

A transgenic (Tg) chimera pig with germ cells carrying a construct expressing Hes1 under the control of the Pdx1 promoter was used to mate with wild-type gilts to obtain Tg piglets.

RESULTS

The Tg pigs showed perinatal death; however, this phenotype could be rescued by insulin treatment. The duodenal and splenic lobes of the Tg pigs were slender and did not fully develop, whereas the connective lobe was absent. β cells were not detected, even in the adult pancreas, although other endocrine cells were detected, and exocrine cells functioned normally. The pigs showed no irregularities in any organs, except diabetes-associated pathological alterations, such as retinopathy and renal damage.

CONCLUSION

Pdx1-Hes1 Tg pigs were an attractive model for the analysis of pancreatic development and testing of novel treatment strategies for diabetes.

Millimeter-thick xenoislet-laden fibers as retrievable transplants mitigate foreign body reactions for long-term glycemic control in diabetic mice

Transplantation technologies of pancreatic islets as well as stem cell-derived pancreatic beta cells encapsulated in hydrogel for the induction of immunoprotection could advance to treat type 1 diabetes mellitus, if the hydrogel transplants acquire retrievability through mitigating foreign body reactions after transplantation. Here, we demonstrate that the diameter of the fiber-shaped hydrogel transplants determines both in vivo cellular deposition onto themselves and their retrievability. Specifically, we found that the in vivo cellular deposition is significantly mitigated when the diameter is 1.0 mm and larger, and that 1.0 mm-thick xenoislet-laden fiber-shaped hydrogel transplants can be retrieved after being placed in the intraperitoneal cavities of immunocompetent diabetic mice for more than 100 days, during which period the hydrogel transplants can normalize the blood glucose concentrations of the mice. These findings could provide an innovative concept of a transplant that would promote the clinical application of stem cell-derived functional cells through improving their in vivo efficacy and safety.

Compensation of Disabled Organogeneses in Genetically Modified Pig Fetuses by Blastocyst Complementation

We have previously established a concept of developing exogenic pancreas in a genetically modified pig fetus with an apancreatic trait, thereby proposing the possibility of in vivo generation of functional human organs in xenogenic large animals. In this study, we aimed to demonstrate a further proof-of-concept of the compensation for disabled organogeneses in pig, including pancreatogenesis, nephrogenesis, hepatogenesis, and vasculogenesis. These dysorganogenetic phenotypes could be efficiently induced via genome editing of the cloned pigs. Induced dysorganogenetic traits could also be compensated by allogenic blastocyst complementation, thereby proving the extended concept of organ regeneration from exogenous pluripotent cells in empty niches during various organogeneses. These results suggest that the feasibility of blastocyst complementation using genome-edited cloned embryos permits experimentation toward the in vivo organ generation in pigs from xenogenic pluripotent cells.

Pigs with δ-sarcoglycan deficiency exhibit traits of genetic cardiomyopathy

Genetic cardiomyopathy is a group of intractable cardiovascular disorders involving heterogeneous genetic contribution. This heterogeneity has hindered the development of life-saving therapies for this serious disease. Genetic mutations in dystrophin and its associated glycoproteins cause cardiomuscular dysfunction. Large animal models incorporating these genetic defects are crucial for developing effective medical treatments, such as tissue regeneration and gene therapy. In the present study, we knocked out the δ-sarcoglycan (δ-SG) gene (SGCD) in domestic pig by using a combination of efficient de novo gene editing and somatic cell nuclear transfer. Loss of δ-SG expression in the SGCD knockout pigs caused a concomitant reduction in the levels of α-, β-, and γ-SG in the cardiac and skeletal sarcolemma, resulting in systolic dysfunction, myocardial tissue degeneration, and sudden death. These animals exhibited symptoms resembling human genetic cardiomyopathy and are thus promising for use in preclinical studies of next-generation therapies.

Correction: Pigs with δ-sarcoglycan deficiency exhibit traits of genetic cardiomyopathy

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P4384Noninvasive and novel method to evaluate left ventricular contractility using pressure-volume loop area obtained by 3-dimensional speckle tracking echocardiography

Introduction

Left ventricular (LV) pressure-volume (P-V) loop area reflects stroke work (SW), but clinical use of this index is limited by the need of invasive pressure measurement. A noninvasive method to obtain LV pressure-strain loop was recently introduced to assess myocardial work (MW). The minimum LV diastolic pressure (mLVP) was reported to have a strong correlation with Tau and we reported that Tau was noninvasively evaluated by speckle tracking echocardiography (STE).

Purpose

We sought to evaluate the impact of preload change by leg lifts on LV SW noninvasively obtained by the novel method and to examine the utility to assess LV contractility by SW and end-diastolic (ED) volume relation (SW-VED).

Methods

Thirty six controls (age 71±10) and 30 patients with heart failure with reduced ejection fraction (EF) <50% (HF) (age 73±6) were enrolled. LV pressure in a cardiac cycle was estimated using systolic blood pressure (SBP), minimum diastolic pressure (mDP) and ED pressure (EDP) by utilizing the profile of an empiric, normalized reference curve. The mDP and EDP were estimated as (Tau − 33.7)/2.06 and as 12.3 − 10.1 x Log (left atrial active emptying function/minimum volume) as we reported. LVSW was obtained by P-V loop by the combination of these pressures and LV volume using 3-D STE.

Results

LVEF and longitudinal strain in HF before leg up by 3D-STE were lower compared to normal (LVEF; normal: 58±5 vs HF: 39±10*% and strain; −12±3 vs −8±3%*, *p<0.05 vs normal). LVEF was increased after leg up by 7±6% in normal and by 8±8% in HF associated with increased LVED volume (normal: 84±24 to 90±24 and HF: 124±36* to 136±42*ml). LV MW and SW in HF before leg up were lower compared to normal (MW: 1790±412 vs 1002±432*mmHg% and SW: 3946±1682 vs 3352±1026mmHgml). LV SW increased after leg up by 26±19% in normal and by 25±20% in HF. LV SW-VED in normal was greater than HF (241±151 vs 90±54*).

Conclusion

LV SW noninvasively obtained by P-V loop area was increased after leg up in both normal and HF but SW-VED in HF was smaller than normal, indicating reduced contractility in HF. This noninvasive method may be a new echocardiographic approach for quantification of LV SW and contractility.

P3548Noninvasive estimation of left ventricular diastolic function in patients with hypertension and normal ejection fraction using 3-dimensional speckle tracking echocardiography

Background

Left ventricular (LV) relaxation (eTau) and pulmonary capillary wedge pressure (ePCWP) were reported to be estimated by speckle tracking echocardiography (STE). LV camber stiffness (e-c stiffness) may be estimated with the use of 2 diastolic pressure-volume coordinates. The minimum diastolic pressure (mP) is reported to have a strong correlation with Tau.

Purpose

We sought to examine the impact of hypertension on LV diastolic function and LA properties and to elucidate the feature of hypertensive heart failure with preserved EF (HFpEF).

Methods

The e', E/e', Tau, PCWP, LVEDP, LV stiffness, LAV, LA emptying function (LAEF) and LA strain were examined in 53 controls (age 66±11), 136 hypertensive patients (HTN) with normal EF (69±11) and 39 HFpEF (77±14). ePCWP and estimated EDP (eEDP) was calculated as previously reported. Tau was calculated as isovolumic relaxation time/(ln 0.9 x systolic blood pressure − ln PCWP). Myocardial stiffness (e-m stiffness) was estimated as LVED stress/LV strain. LV c-stiffness was calculated as LV pressure change (from mP to EDP) obtained by catheterization divided by LV volume change. Estimated LV c-stiffness (e-c-stiffness) was noninvasively obtained using e-mP and e-EDP. The eTau, eEDP and e-mP by STE were validated by catheterization (n=126).

Results

The mP had a good correlation with Tau (r=0.70, p<0.01). The eTau, eEDP and e-mP by STE had a good correlation with those by catheterization (r=0.75, 0.63 and 0.70, p<0.01). Multivariate analysis revealed that ePCWP and LA strain were independent predictors of HFpEF.

LV diastoric function Variables Control HTN HFpEF LVEF, % 68±6 68±8 63±9*+ LV longitudinal strain x (s–1) 19.1±3.0 16.8±4.3* 14.5±5.1*+ E/e' 9.2±2.6 11.6±4.5* 15.9±7.9*+ eTau, ms 35±12 48±17* 59±17*+ ePCWP, mmHg 7.3±2.7 8.3±4.3 15.0±4.4*+ eLVEDP, mmHg 9.4±2.2 10.4±3.5 15.9±3.7*+ LV e-myocardial stiffness, kdynes/cm 0.56±0.25 0.69±0.56 1.27±0.71*+ LV e-chamber stiffness, mmHg/ml 0.19±0.06 0.20±0.08 0.36±0.19*+ Maximum LAVI, ml/m2 42±15 50±21* 68±17*+ Total LAEF, % 55±7 51±11 36±12*+ LA peak strain 41±15 40±17 19±8*+ *p<0.05 vs Control, +p<0.05 vs HTN.

Conclusion

We demonstrated that LV diastolic function in HTN may be accurately and noninvasively evaluated by STE.

P2474Noninvasive estimation of pulmonary capillary wedge pressure by novel 3D speckle tracking echocardiography and validation study by cardiac catheterization

Background

We previously reported that pulmonary capillary wedge pressure (PCWP) was noninvasively evaluated by 2D speckle tracking echocardiography (STE). Recently, novel software was introduced to examine volume and function of left ventricular and left atrium (LA) by 3D-STE automatically.

Purpose

We sought to compare the PCWP estimated by conventional 2D-STE (2D-ePCWP) and by novel 3D-STE (3D-ePCWP), and validate those values by cardiac catheterization.

Methods

Echocardiography and catheterization were performed in 29 patients (age 72±2) (7 ischemic heart disease, 2 hypertensive heart disease, 5 dilated cardiomyopathy, 12 valvular heart disease and 3 primary pulmonary hypertension).The ePCWP (mmHg) is noninvasively obtained as 10.8 − 12.4 x Log (left atrial active emptying function/minimum volume) as we previously reported. Echocardiography was performed just before the catheterization and we analyzed the 2D and 3D data by novel off-line software. 3D data was automatically analyzed and the border settings were fixed at default (ES60, ED30) (Figure).

Results

2D-ePCWP and 3D-ePCWP had a good correlation with PCWP invasively obtained by catheterization (r=0.87 and 0.83, respectively, both p<0.001). There was an excellent correlation between 2D-ePCWP and 3D-ePCWP (r=0.94, p<0.001) and there was a good correlation between 2D-LA volume index and 3D- LA volume index (r=0.80, p<0.001). Bland-Altman analysis revealed a good agreement between 2D-ePCWP and 3D-ePCWP, and between 2D-ePCWP and 3D-ePCWP without fixed and proportional bias.

Conclusion

This study demonstrated that PCWP might be noninvasively assessed by not only 2D-STE but also 3D-STE with reasonable accuracy and 3D-STE might have utility and value in the routine clinical practice.

P4351Validation by cardiac catheterization of noninvasive evaluation of left ventricular chamber and myocardial stiffness as a diastolic function using speckle tracking echocardiography

Background

Left ventricular (LV) diastolic function is mainly composed of LV relaxation and LV stiffness. We reported that pulmonary capillary wedge pressure (ePCWP) and LV relaxation assessed by Tau (eTau) are noninvasively evaluated by speckle tracking echocardiography (STE). The minimum LV diastolic pressure (mLVP) was reported to have a strong correlation with Tau. Therefore, LV chamber stiffness (c-stiffness) may be assessed with the use of two LV diastolic pressure-volume coordinates: the mLVP and volume and the end-diastolic pressure (EDP) and volume.

Purpose

We sought to noninvasively assess LV stiffness using STE and validate the value by cardiac catheterization.

Methods

Echocardiography and catheterization were performed in 124 patients (age 72±8) (70 angina pectoris, 20 prior myocardial infarction, 19 hypertensive heart disease, 11 congestive heart failure and 4 paroxysmal atrial fibrillation). The ePCWP (mmHg) is noninvasively obtained as 10.8 − 12.4 × Log (left atrial active emptying function/minimum volume) and the eTau (ms) is obtained as isovolumic relaxation time/(ln 0.9 × systolic blood pressure − ln ePCWP) as previously reported. The mLVP (e-mLVP) was estimate using Tau. The estimated EDP (e-EDP) was calculated as 12.3 − 10.1 × Log (left atrial active emptying function / minimum volume). LV c-stiffness (mmHg/ml) was calculated as LV pressure change (from mLVP to EDP) obtained by catheterization divided by LV volume change during diastole which equals to stroke volume by echocardiography. Estimated c-stiffness (e-c-stiffness) was noninvasively obtained using e-mLVP and e-EDP. Furthermore, LV myocardial stiffness (m-stiffness) was calculated by LVED stress / LV longitudinal strain by STE, where LV stress (kdynes/cm2) was calculated as 0.334 × pressure × dimension / [thickness (1 + thickness/dimension)]. The estimated m-stiffness (e-m-stiffness) was calculated using e-EDP.

Results

The eTau and e-EDP estimated by STE had a good correlation with Tau and EDP invasively obtained by catheterization (r=0.75 and 0.63, respectively, both p<0.001). There was a good correlation between Tau and mLVP (Tau = 2.06 mLVP + 33.7, r=0.70). The estimated LVED stress had good correlation with ED stress obtained by catheterization (r=0.77, p<0.001). The e-c-stiffness and e-m-stiffness had a good correlation with those obtained by catheterization (e-c-stiffness; 0.116±0.07 and c-stiffness; 0.115±0.06, r=0.603, e-m-stiffness; 0.81±0.41 and m-stiffness; 0.85±0.45, r=0.89, respectively). Bland-Altman analysis revealed a good agreement between e-c-stiffness and c-stiffness, and between e-m-stiffness and m-stiffness without fixed and proportional bias.

Conclusion

This study demonstrated that LV stiffness may be noninvasively assessed by STE with reasonable accuracy and may have utility and value in the routine clinical practice for the diagnosis and treatment in patients with diastolic dysfunction.

Distributions of endocrine cell clusters during porcine pancreatic development

Background

Pancreatic islet xenotransplantation is a potential treatment for diabetes mellitus, and porcine pancreas may provide a readily available source of islets. Islets in juvenile pigs are smaller than those in young adult pigs, but the insulin content is very similar. In addition, as juvenile pigs are more easily reared in uncontaminated conditions, many researchers have conducted studies using pancreatic islets from juvenile pigs. We aimed to analyze the distributions of endocrine cell clusters by comprehensively evaluating juvenile porcine pancreatic development and to propose an appropriate age at which islets could be isolated from the juvenile porcine pancreas.

Methods

Splenic (SL) and duodenal lobe (DL) samples were collected from the pancreases of pigs aged 0–180 days (n = 3/day after birth). The chronological changes in endocrine cell clustering were analyzed in relation to morphological changes, cell characterization, numbers, islet areas, and gene expression.

Results

In juvenile pigs aged 0–21 days, the pancreas contained numerous endocrine cells, and compact islets appeared from 21 days of age. Well-defined small islets were seen at 28 days of age, and the clusters were denser in the SL than in the DL. At 35 days of age, the islets were morphologically similar to those observed at 180 days of age, and the greater number of islets was similar to that seen at 90 days of age. The differences in the islets’ cytoarchitecture between the lobes were negligible. The expression of β-cell-related genes was higher in the juvenile pancreas than in the adult pancreas, and the expression of neurogenin-3 decreased dramatically over time.

Conclusions

These findings may have implications for attempts to refine the most appropriate age for islet isolation from porcine donors. Focusing on porcine pancreatic islets isolated at around 35 days after birth may offer benefits regarding their xenotransplantation potential.

The phenotype of a pig with monosomy X resembling Turner syndrome symptoms: a case report

The partial or complete loss of one X chromosome in humans causes Turner syndrome (TS), which is accompanied by a range of physical and reproductive pathologies. This article reports similarities between the phenotype of a pig with monosomy X and the symptoms of TS in humans. Born as the offspring of a male pig carrying a mutation in an X-chromosomal gene, ornithine transcarbamylase (OTC), the female pig (37,XO) was raised to the age of 36 months. This X-monosomic pig presented with abnormal physical characteristics including short stature, micrognathia, and skeletal abnormalities in the limbs. Furthermore, the female did not exhibit an estrous cycle, even after reaching the age of sexual maturity, and showed no ovarian endocrine activity except for an irregular increase in blood 17β-estradiol levels, which was seemingly attributable to sporadic follicular development. An autopsy at 36 months revealed an undeveloped reproductive tract with ovaries that lacked follicles. These data demonstrated that the growth processes and anatomical and physiological characteristics of an X-monosomic pig closely resembled those of a human with TS.

Refractory Hypotension during Combined General and Epidural Anaesthesia in a Patient on Tricyclic Antidepressants

We report a case of refractory hypotension that occurred after epidural injection of local anaesthetic, in a patient who was receiving tricyclic antidepressant therapy and was under general anaesthesia. The patient failed to respond to repeated injections of appropriate doses of sympathomimetics, but did respond to high-dose catecholamine infusions. We suggest that epidural anaesthesia should be used with care when combined with general anaesthesia for patients on long-standing tricyclic antidepressant therapy. If refractory hypotension should occur in such patients, the use of direct-acting vasoconstrictors such as noradrenaline should be considered.

Effectiveness of bioengineered islet cell sheets for the treatment of diabetes mellitus

BACKGROUND

The present study aimed to evaluate whether bioengineered mouse islet cell sheets can be used for the treatment of diabetes mellitus.

METHODS

Isolated mouse pancreatic islets were dispersed, and cells were plated on temperature-responsive culture plates coated with iMatrix-551. On day 3 of culture, the sheets were detached from the plates and used for further analysis or transplantation. The following parameters were assessed: (1) morphology, (2) expression of β-cell-specific transcription factors and other islet-related proteins, (3) methylation level of the pancreatic duodenal homeobox-1 (Pdx-1) promoter, as determined by bisulfite sequencing, and (4) levels of serum glucose after transplantation of one or two islet cell sheets into the abdominal cavity of streptozotocin-induced diabetic severe combined immunodeficiency mice.

RESULTS

From each mouse, we recovered approximately 233.3 ± 12.5 islets and 1.4 ± 0.1 × 10⁵ cells after dispersion. We estimate that approximately 68.2% of the cells were lost during dispersion. The viability of recovered single cells was 91.3 ± 0.9%. The engineered islet cell sheets were stable, but the messenger RNA levels of various β-cell-specific transcription factors were significantly lower than those of primary islets, whereas Pdx-1 promoter methylation and the expression of NeuroD, Pdx-1, and glucagon proteins were similar between sheets and islets. Moreover, transplantation of islet cell sheets did not revert serum hyperglycemia in any of the recipient mice.

CONCLUSIONS

Engineering effective islet cell sheets require further research efforts, as the currently produced sheets remain functionally inferior compared with primary islets.

Diabetic phenotype of transgenic pigs introduced by dominant-negative mutant hepatocyte nuclear factor 1α

AIM

The present study aimed to identify the characteristics of genetically modified pigs carrying a mutant human gene as a research model for diabetes and its complications.

METHODS

We developed a transgenic cloned pig (founder, male) carrying a mutant gene, i.e., human HNF-1α (P291fsinsC), which is responsible for maturity-onset diabetes of the young type 3. Transgenic progeny obtained via the artificial insemination of wild type (WT) sows with the cryopreserved sperm derived from the founder pig was pathologically examined.

RESULTS

The transgenic progeny maintained a high blood glucose level (>200mg/dL). Additionally, the oral glucose tolerance test results showed that the recovery of blood glucose levels in the transgenic progeny was significantly delayed compared with that in the WT semi-siblings. Hypoplasia of the islets of Langerhans was confirmed by the histopathological image of the pancreas, based on the hyperglycemia noted in the progeny being ascribed to decreased insulin secretion. Retinal hemorrhage and cotton-wool spots, i.e., findings consistent with non-proliferative diabetic retinopathy, were detected, and these progressed over time. The histopathological image of the renal glomeruli showed a nodular lesion that is characteristic of diabetic nephropathy in humans.

CONCLUSIONS

These data demonstrated that the genetically modified pig that we developed is a promising model for research on diabetes and its complications.

Injectable chelate-setting hydroxyapatite cement prepared by using chitosan solution: Fabrication, material properties, biocompatibility, and osteoconductivity

An injectable chelate-setting hydroxyapatite cement (IP6-HAp), formed by chelate-bonding capability of inositol phosphate (IP6), was developed. The effects of ball-milling duration of starting HAp powder and IP6 concentration on the material properties such as injectability and mechanical strength of the cement were examined. The cement powder was prepared by ball-milling the as-synthesized HAp powder for 5 min using ZrO2 beads with a diameter of 10 mm, followed by another 60 min with ZrO2 beads with a diameter of 2 mm, and thereafter surface-modified with 5000 ppm of IP6 solution. Injectable cement was then fabricated with this HAp powder and 2.5 mass% chitosan as a mixing solution, with a setting time of 36.3 ± 4.7 min and a compressive strength of 19.0 ± 2.1 MPa. The IP6-HAp cements prepared with chitosan showed favorable biocompatibility in vitro using an osteoblast cell model, and osteoconductivity in vivo using a pig tibia model.

Host conditioning and rejection monitoring in hepatocyte transplantation in humans

BACKGROUND & AIMS

Hepatocyte transplantation partially corrects genetic disorders and has been associated anecdotally with reversal of acute liver failure. Monitoring for graft function and rejection has been difficult, and has contributed to limited graft survival. Here we aimed to use preparative liver-directed radiation therapy, and continuous monitoring for possible rejection in an attempt to overcome these limitations.

METHODS

Preparative hepatic irradiation was examined in non-human primates as a strategy to improve engraftment of donor hepatocytes, and was then applied in human subjects. T cell immune monitoring was also examined in human subjects to assess adequacy of immunosuppression.

RESULTS

Porcine hepatocyte transplants engrafted and expanded to comprise up to 15% of irradiated segments in immunosuppressed monkeys preconditioned with 10Gy liver-directed irradiation. Two patients with urea cycle deficiencies had early graft loss following hepatocyte transplantation; retrospective immune monitoring suggested the need for additional immunosuppression. Preparative radiation, anti-lymphocyte induction, and frequent immune monitoring were instituted for hepatocyte transplantation in a 27year old female with classical phenylketonuria. Post-transplant liver biopsies demonstrated multiple small clusters of transplanted cells, multiple mitoses, and Ki67⁺ hepatocytes. Mean peripheral blood phenylalanine (PHE) level fell from pre-transplant levels of 1343±48μM (normal 30-119μM) to 854±25μM (treatment goal ≤360μM) after transplant (36% decrease; p<0.0001), despite transplantation of only half the target number of donor hepatocytes. PHE levels remained below 900μM during supervised follow-up, but graft loss occurred after follow-up became inconsistent.

CONCLUSIONS

Radiation preconditioning and serial rejection risk assessment may produce better engraftment and long-term survival of transplanted hepatocytes. Hepatocyte xenografts engraft for a period of months in non-human primates and may provide effective therapy for patients with acute liver failure.

LAY SUMMARY

Hepatocyte transplantation can potentially be used to treat genetic liver disorders but its application in clinical practice has been impeded by inefficient hepatocyte engraftment and the inability to monitor rejection of transplanted liver cells. In this study, we first show in non-human primates that pretreatment of the host liver with radiation improves the engraftment of transplanted liver cells. We then used this knowledge in a series of clinical hepatocyte transplants in patients with genetic liver disorders to show that radiation pretreatment and rejection risk monitoring are safe and, if optimized, could improve engraftment and long-term survival of transplanted hepatocytes in patients.

Changes in Muscle Strength and Six-Minute Walk Distance Before and After Living Donor Liver Transplantation

BACKGROUND

Impaired exercise capacity and muscle weakness are important characteristics of liver transplantation recipients. Perioperative rehabilitation has been introduced to promote early mobilization of patients and to prevent postoperative pulmonary complications. However, it is unknown how physical status recovers during the hospital stay after a liver transplant. The purpose of this study was to evaluate the changes in clinical indicators that represent the functional exercise capacity and muscle strength before and after living donor liver transplantation (LDLT).

METHODS

We retrospectively reviewed 21 consecutive patients who underwent LDLT with perioperative rehabilitation from April 2014 to December 2015. Twelve patients who were tested for 6-minute walk distance, hand-grip strength, and isometric knee extensor muscle strength before and 4 weeks after LDLT were enrolled.

RESULTS

At the preoperative baseline, the 6-minute walk distance significantly correlated with the Model for End-stage Liver Disease score and pulmonary functions (vital capacity, forced vital capacity, and forced expiratory volume in 1 second of predictive values). Comparisons between the preoperative and postoperative values revealed significant decreases in weight, Barthel Index, hand-grip strength, and isometric knee extensor muscle strength. Changes in hand-grip strength and isometric knee extensor muscle strength after LDLT correlated with the preoperative Model for End-stage Liver Disease score.

CONCLUSIONS

Physical functional status had not been fully recovered 4 weeks after LDLT. Further investigation regarding developing a strategy for prevention of muscle atrophy before LDLT and recovery of physical fitness after LDLT would be helpful.

An Effective New Cryopreservation Procedure for Pancreatic Islets Using Hollow Fiber Vitrification

The present study aimed at establishing a new cryopreservation method for mouse pancreatic islets by vitrification using hollow fibers as a container. A unique feature of the hollow fiber vitrification (HFV) method is that this method achieves stable vitrification using a minimum volume of cryoprotectant (CPA) solution, thereby ensuring high viability of the islets. The cytotoxicity, optimum composition, and concentration of the CPAs for vitrifying islets were examined. The viability, functional-integrity of vitrified islets were evaluated in comparison with those vitrified by conventional methods. Insulin secretion was measured in vitro by a static incubation assay and the metabolic functions was tested after transplantation into Streptozotocin-induced diabetic mice. The combination of 15% dimethyl sulfoxide+15% ethylene glycol resulted in the best CPA solution for the HFV of islets. HFV showed the highest viability in comparison to 2 vitrification methods, open pulled straws and vitrification with EDT324 solution. The vitrified islets stably expressed β-cells markers NeuroD, Pancreatic and duodenal homeobox-1, and MafA. Transplantation of the vitrified islets achieved euglycemia of the host diabetic mice and response to an intraperitoneal glucose tolerance test to a similar extent as non-vitrified transplanted islets. The HFV method allows for efficient long-term cryopreservation of islets.

A transgenic-cloned pig model expressing non-fluorescent modified Plum

Genetically modified pigs that express fluorescent proteins such as green and red fluorescent proteins have become indispensable biomedical research tools in recent years. Cell or tissue transplantation studies using fluorescent markers should be conducted, wherein the xeno-antigenicity of the fluorescent proteins does not affect engraftment or graft survival. Thus, we aimed to create a transgenic (Tg)-cloned pig that was immunologically tolerant to fluorescent protein antigens. In the present study, we generated a Tg-cloned pig harboring a derivative of Plum modified by a single amino acid substitution in the chromophore. The cells and tissues of this Tg-cloned pig expressing the modified Plum (mPlum) did not fluoresce. However, western blot and immunohistochemistry analyses clearly showed that the mPlum had the same antigenicity as Plum. Thus, we have obtained primary proof of principle for creating a cloned pig that is immunologically tolerant to fluorescent protein antigens.

Generation of α1,3-galactosyltransferase and cytidine monophospho-N-acetylneuraminic acid hydroxylase gene double-knockout pigs

Zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) are new tools for producing gene knockout (KO) animals. The current study reports produced genetically modified pigs, in which two endogenous genes were knocked out. Porcine fibroblast cell lines were derived from homozygous α1,3-galactosyltransferase (GalT) KO pigs. These cells were subjected to an additional KO for the cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH) gene. A pair of ZFN-encoding mRNAs targeting exon 8 of the CMAH gene was used to generate the heterozygous CMAH KO cells, from which cloned pigs were produced by somatic cell nuclear transfer (SCNT). One of the cloned pigs obtained was re-cloned after additional KO of the remaining CMAH allele using the same ZFN-encoding mRNAs to generate GalT/CMAH-double homozygous KO pigs. On the other hand, the use of TALEN-encoding mRNAs targeting exon 7 of the CMAH gene resulted in efficient generation of homozygous CMAH KO cells. These cells were used for SCNT to produce cloned pigs homozygous for a double GalT/CMAH KO. These results demonstrate that the combination of TALEN-encoding mRNA, in vitro selection of the nuclear donor cells and SCNT provides a robust method for generating KO pigs.

Induced pluripotent stem cells model personalized variations in liver disease resulting from α1-antitrypsin deficiency

In the classical form of α1-antitrypsin deficiency (ATD), aberrant intracellular accumulation of misfolded mutant α1-antitrypsin Z (ATZ) in hepatocytes causes hepatic damage by a gain-of-function, "proteotoxic" mechanism. Whereas some ATD patients develop severe liver disease (SLD) that necessitates liver transplantation, others with the same genetic defect completely escape this clinical phenotype. We investigated whether induced pluripotent stem cells (iPSCs) from ATD individuals with or without SLD could model these personalized variations in hepatic disease phenotypes. Patient-specific iPSCs were generated from ATD patients and a control and differentiated into hepatocyte-like cells (iHeps) having many characteristics of hepatocytes. Pulse-chase and endoglycosidase H analysis demonstrate that the iHeps recapitulate the abnormal accumulation and processing of the ATZ molecule, compared to the wild-type AT molecule. Measurements of the fate of intracellular ATZ show a marked delay in the rate of ATZ degradation in iHeps from SLD patients, compared to those from no liver disease patients. Transmission electron microscopy showed dilated rough endoplasmic reticulum in iHeps from all individuals with ATD, not in controls, but globular inclusions that are partially covered with ribosomes were observed only in iHeps from individuals with SLD.

CONCLUSION

iHeps model the individual disease phenotypes of ATD patients with more rapid degradation of misfolded ATZ and lack of globular inclusions in cells from patients who have escaped liver disease. The results support the concept that "proteostasis" mechanisms, such as intracellular degradation pathways, play a role in observed variations in clinical phenotype and show that iPSCs can potentially be used to facilitate predictions of disease susceptibility for more precise and timely application of therapeutic strategies.

Production of transgenic cloned pigs expressing the far-red fluorescent protein monomeric Plum

Monomeric Plum (Plum), a far-red fluorescent protein with photostability and photopermeability, is potentially suitable for in vivo imaging and detection of fluorescence in body tissues. The aim of this study was to generate transgenic cloned pigs exhibiting systemic expression of Plum using somatic cell nuclear transfer (SCNT) technology. Nuclear donor cells for SCNT were obtained by introducing a Plum-expression vector driven by a combination of the cytomegalovirus early enhancer and chicken beta-actin promoter into porcine fetal fibroblasts (PFFs). The cleavage and blastocyst formation rates of reconstructed SCNT embryos were 81.0% (34/42) and 78.6% (33/42), respectively. At 36-37 days of gestation, three fetuses systemically expressing Plum were obtained from one recipient to which 103 SCNT embryos were transferred (3/103, 2.9%). For generation of offspring expressing Plum, rejuvenated PFFs were established from one cloned fetus and used as nuclear donor cells. Four cloned offspring and one stillborn cloned offspring were produced from one recipient to which 117 SCNT embryos were transferred (5/117, 4.3%). All offspring exhibited high levels of Plum fluorescence in blood cells, such as lymphocytes, monocytes and granulocytes. In addition, the skin, heart, kidney, pancreas, liver and spleen also exhibited Plum expression. These observations demonstrated that transfer of the Plum gene did not interfere with the development of porcine SCNT embryos and resulted in the successful generation of transgenic cloned pigs that systemically expressed Plum. This is the first report of the generation and characterization of transgenic cloned pigs expressing the far-red fluorescent protein Plum.

31 PRODUCTION EFFICIENCY OF GENE KNOCKOUT PIGS USING GENOME EDITING AND SOMATIC CELL CLONING

Genome editing technologies have been used as a powerful strategy for the generation of genetically modified pigs. We previously developed genetically modified clone pigs with organogenesis-disabled phenotypes, as well as pigs exhibiting diseases with similar features to those of humans. Here, we report the production efficiency of various gene knockout cloned pigs from somatic cells that were genetically modified using zinc finger nucleases (ZFN) or transcription activator-like effector nucleases (TALEN). The ZFN- or TALEN-encoding mRNAs, which targeted 7 autosomal or X-linked genes, were introduced into porcine fetal fibroblast cells using electroporation. Clonal cell populations carrying induced mutations were selected after limiting dilution. The targeted portion of the genes was amplified using PCR, followed by sequencing and mutation analysis. Among the collected knockout cell colonies, cells showing good proliferation and morphology were selected and used for somatic cell nuclear transfer (SCNT). In vitro-matured oocytes were obtained from porcine cumulus-oocyte complexes cultured in NCSU23-based medium and were used to obtain recipient oocytes for SCNT after enucleation. SCNT was performed as reported previously (Matsunari et al. 2008). The cloned embryos were cultured for 7 days in porcine zygote medium (PZM)-5 to assess their developmental ability. Cloned embryos were transplanted into the oviduct or uterus of oestrus-synchronized recipient gilts to evaluate their competence to develop to fetuses or piglets. Cloned embryos reconstructed with 7 types of knockout cells showed equal development to blastocysts compared with those derived from the wild-type cells (54.5–83.3% v. 60.7%). Our data (Table 1) demonstrated that the reconstructed embryos derived from knockout cells could efficiently give rise to cloned offspring regardless of the type of genome editing methodology (i.e. ZFN or TALEN). Table 1.Production efficiency of gene knockout cloned pigs using genome editing This study was supported by JST, ERATO, the Nakauchi Stem Cell and Organ Regeneration Project, JST, CREST, Meiji University International Institute for Bio-Resource Research (MUIIBR), and JSPS KAKENHI Grant Number 26870630.

Therapeutic effect of intratumoral injections of dendritic cells for locally recurrent gastric cancer: a case report

An 80-year-old man with a history of gastric cancer and pulmonary emphysema underwent a distal gastrectomy for gastric cancer in 1997. In 2010, an endoscopic examination revealed a depressed-type lesion at the oral side of the anastomosis, which was diagnosed as signet-ring adenocarcinoma. Surgical management was considered, but was rejected because of obstructive and restrictive respiratory events. Chemotherapy was terminated because of adverse events. Endoscopy was used to administer intratumoral injections of dendritic cells (DCs) targeting synthesized peptides of Wilms tumor 1 (WT1) and mucin 1, cell-surface associated (MUC1). An immunohistochemical analysis of the tumor samples indicated positivity for WT1 and MUC1. One month after seven cycles of DC had been administered (between November 2010 and April 2011), no suspicious lesions were evident, and his biopsy results were normal. The patient has been in remission for 30 months. Intratumoral injections of DCs showed therapeutic effects in this patient, who could not undergo endoscopic submucosal dissection or surgery.

A conserved rule for pancreatic islet organization

Morphogenesis, spontaneous formation of organism structure, is essential for life. In the pancreas, endocrine , , and cells are clustered to form islets of Langerhans, the critical micro-organ for glucose homeostasis. The spatial organization of endocrine cells in islets looks different between species. Based on the three-dimensional positions of individual cells in islets, we computationally inferred the relative attractions between cell types, and found that the attractions between homotypic cells were slightly, but significantly, stronger than the attractions between heterotypic cells commonly in mouse, pig, and human islets. The difference between cell attraction and cell attraction was minimal in human islets, maximizing the plasticity of islet structures. Our result suggests that although the cellular composition and attractions of pancreatic endocrine cells are quantitatively different between species, the physical mechanism of islet morphogenesis may be evolutionarily conserved.

Abstract 2813: Survival benefit of an add-on dendritic cell vaccine for patients with inoperable pancreatic cancer receiving chemotherapy: a multicenter study

Purpose: Dendritic cell (DC)-based cancer vaccine may have a significant benefit to patients with advanced pancreatic cancer. However, variations among clinical studies make it hard to detect its clinical outcome. Here we statistically identified factors determining the clinical benefit using data obtained at seven Japanese institutions that employed the same DC preparation and treatment regimen.

Patients and Methods: Among the 354 patients who met the inclusion criteria, 255 patients who received standard chemotherapy combined with peptide-pulsed DC vaccines were analyzed.

Results: The mean survival time from diagnosis was 16.5 months (95%CI=14.4-18.5), and that from the first vaccination was 9.9 months (95%CI=8.0-12.9). Known prognostic baseline factors related to advanced pancreatic cancer, namely ECOG-PS, peritoneal metastasis, liver metastasis, and prognostic nutrition index (PNI) were also representative. Importantly, erythema reaction after vaccination was an independent and treatment-related predictive factor for better survival, and that OK432 might be a good adjuvant enhancing the antitumor immunity during DC vaccination.

Conclusion: This is the first report of a multicenter clinical study suggesting the feasibility and possible clinical benefit of an add-on DC vaccine in patients with advanced pancreatic cancer who are undergoing chemotherapy. These findings need to be addressed in well-controlled prospective randomized trials.

Citation Format: Masanori Kobayashi, Shimodaira Shigetaka, Kazuhiro Nagai, Masahiro Ogasawara, Hidenori Takahashi, Hirofumi Abe, Mitsugu Tanii, Masato Okamoto, Shun-ichi Tsujitani, Masaki Nagaya, Yoshikazu Yonemitsu, The DC vaccine study group of Japan Society of Innovative Cell Therapy (J-SICT). Survival benefit of an add-on dendritic cell vaccine for patients with inoperable pancreatic cancer receiving chemotherapy: a multicenter study. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2813. doi:10.1158/1538-7445.AM2014-2813

Prognostic factors related to add-on dendritic cell vaccines on patients with inoperable pancreatic cancer receiving chemotherapy: a multicenter analysis

OBJECTIVE

Dendritic cell (DC)-based cancer vaccines may have a significant benefit to patients with advanced pancreatic cancer. However, variations among clinical studies make it difficult to compare clinical outcomes. Here, we identified factors that determined the clinical benefits by analyzing data obtained at seven Japanese institutions that employed the same DC preparation and treatment regimens.

METHODS

Of 354 patients who met the inclusion criteria, 255 patients who received standard chemotherapy combined with peptide-pulsed DC vaccines were analyzed.

RESULTS

The mean survival time from diagnosis was 16.5 months (95 % CI 14.4-18.5) and that from the first vaccination was 9.9 months (95 % CI 8.0-12.9). Known prognostic baseline factors related to advanced pancreatic cancer, namely ECOG-PS, peritoneal metastasis, liver metastasis, and the prognostic nutrition index, were also representative. Importantly, we found that erythema reaction after vaccination was an independent and treatment-related prognostic factor for better survival and that OK-432 might be a good adjuvant enhancing the antitumor immunity during DC vaccination.

CONCLUSIONS

This is the first report of a multicenter clinical study suggesting the feasibility and possible clinical benefit of an add-on DC vaccine in patients with advanced pancreatic cancer who are undergoing chemotherapy. These findings need to be addressed in well-controlled prospective randomized trials.