Metabolomics and miRNA profiling reveals feature of gallbladder cancer-derived biliary extracellular vesicles

BACKGROUND

Although there are several studies in the development of various human cancers, the role of exosomes is poorly understood in the progression of gallbladder cancer. This study aims to characterize the metabolic changes occurring in exosomes obtained from patients with gallbladder cancer compared with those from other gallbladder disease groups.

METHODS

Biliary exosomes were isolated from healthy donors (n = 3) and from patients with gallbladder cancer (n = 3), gallbladder polyps (n = 4), or cholecystitis (n = 3) using a validated exosome isolation kit. Afterward, we performed miRNA profiling and untargeted metabolomic analysis of the exosomes. The results were validated by integrating the results of the miRNA and metabolomic analyses.

RESULTS

The gallbladder cancer group exhibited a significant reduction in the levels of multiple unsaturated phosphatidylethanolamines and phosphatidylcholines compared to the normal group, which resulted in the loss of exosome membrane integrity. Additionally, the gallbladder cancer group demonstrated significant overexpression of miR-181c and palmitic acid, and decreased levels of conjugated deoxycholic acid, all of which are strongly associated with the activation of the PI3K/AKT pathway.

CONCLUSIONS

Our findings demonstrate that the contents of exosomes are disease-specific, particularly in gallbladder cancer, and that altered metabolites convey critical information regarding their phenotype. We believe that our metabolomic and miRNA profiling results may provide important insights into the development of gallbladder cancer.

Laparoscopic treatment of paraprostatic cyst in two dogs - complete resection, and partial resection with omentalization: a case report

Two intact male dogs were evaluated for symptoms, including hematuria, prostatomegaly, anuria, lethargy, and abdominal mass. Presurgical evaluations, including complete physical examinations, blood examinations, abdominal radiography with contrast (only in Case 2), ultrasonography, and computed tomography and magnetic resonance imaging (only in Case 1), were performed. A paraprostatic cyst was diagnosed initially, and laparoscopic exploration and surgery were performed. Complete resection was performed in case 1, whereas partial resection with omentalization was performed in case 2. Histopathological examination of the tissue samples confirmed the presence of paraprostatic pseudocysts in both cases, with no evidence of an epithelial lining. These two cases represent the first documented instances of laparoscopic treatment for extraparenchymal prostatic cysts. The laparoscopic treatment proved feasible even in the case of a giant cyst causing anuria (Case 2). Paraprostatic cysts should be considered a potential differential diagnosis for abnormal urination accompanied by an abdominal mass, and long-term postoperative follow-up is necessary.

Surgical Correction of a Sinus Venosus Atrial Septal Defect with Partial Anomalous Pulmonary Venous Connections Using Cardiac Computed Tomography Imaging and a 3D-Printed Model

Sinus venosus atrial septal defects (SVASDs), concurrent with partial anomalous pulmonary venous connections (PAPVCs), are a rare congenital heart disease in dogs. Surgical correction is essential when clinical signs or significant hemodynamic changes are present. We aimed to report on the successful surgical correction of an SVASD with PAPVCs, using a computed tomography (CT)-based customized 3D cardiac model. A 10-month-old male poodle was referred for corrective surgery for an ASD. Echocardiography confirmed a hemodynamically significant left-to-right shunting flow through an interatrial septal defect and severe right-sided heart volume overload. For a comprehensive diagnosis, a CT scan was performed, which confirmed an SVASD with PAPVCs. A customized 3D cardiac model was used for preoperative decision-making and surgical rehearsal. The defect was repaired using an autologous pericardial patch under a cardiopulmonary bypass (CPB). Temporary pacing was applied for sinus bradycardia and third-degree atrioventricular block. The patient recovered from the anesthesia without further complications. The pacemaker was removed during hospitalization and the patient was discharged without complications 2 weeks post-surgery. At the three-month follow-up, there was no shunting flow in the interatrial septum and the right-sided volume overload had been resolved. The cardiac medications were discontinued, and there were no complications. This report indicates the validity of surgical correction under CPB for an SVASD with PAPVCs, and the advantages of utilizing a CT-based 3D cardiac model for preoperative planning to increase the surgical success rate.

Development of machine learning models for the surveillance of colon surgical site infections

BACKGROUND

Conventional surgical site infection (SSI) surveillance is labour-intensive. We aimed to develop machine learning (ML) models for the surveillance of SSIs for colon surgery and to assess whether the ML could improve surveillance process efficiency.

METHODS

This study included cases who underwent colon surgery at a tertiary center between 2013 and 2014. Logistic regression and four ML algorithms including random forest (RF), gradient boosting (GB), and neural networks (NNs) with or without recursive feature elimination (RFE) were first trained on the entire cohort, and then re-trained on cases selected based on a previous rule-based algorithm. We assessed model performance based on the area under the curve (AUC), sensitivity, and positive predictive value (PPV). The estimated proportion of reduction in workload for chart review based on the ML models was evaluated and compared with the conventional method.

RESULTS

At a sensitivity of 95%, the NN with RFE using 29 variables had the best performance with an AUC of 0.963 and PPV of 21.1%. When combining both the rule-based algorithm and ML algorithms, the NN with RFE using 19 variables had a higher PPV (28.9%) than with the ML algorithm alone, which could decrease the number of cases requiring chart review by 83.9% compared with the conventional method.

CONCLUSION

We demonstrated that ML can improve the efficiency of SSI surveillance for colon surgery by decreasing the burden of chart review while providing high sensitivity. In particular, the hybrid approach of ML with a rule-based algorithm showed the best performance in terms of PPV.

Management of newborns and healthcare workers exposed to isoniazid-resistant congenital tuberculosis in the neonatal intensive care unit

BACKGROUND

Management of newborns and healthcare workers (HCWs) exposed to congenital tuberculosis (TB) in the neonatal intensive care unit (NICU) has been reported rarely.

AIM

To outline a contact investigation process for individuals exposed to congenital TB in the NICU and investigate nosocomial transmission. Additionally, to assess the efficacy and safety of window prophylaxis in exposed newborns.

METHODS

A baby, born at a gestational age of 28 + 1 weeks, was diagnosed with isoniazid-resistant congenital TB on the 39th day of admission to the level IV NICU. Newborns and HCWs exposed cumulatively for ≥8 h underwent contact investigation and follow-up for a year.

FINDINGS

Eighty-two newborns underwent contact investigation. All newborns displayed normal chest X-rays, and 42 hospitalized newborns tested negative for acid-fast bacilli stain and Xpert® MTB/RIF assay in their endotracheal sputum or gastric juices. Eighty received window prophylaxis: six of 75 on rifampin experienced mild adverse events, and none of the five on levofloxacin. After 12 weeks, five (6.1%) had a positive tuberculin skin test, all of whom had already received the Bacillus Calmette-Guérin vaccine and tested negative on TB interferon-gamma releasing assay. Of 119 exposed HCWs, three (2.5%) were diagnosed with latent TB infection and completed a four-month rifampin therapy. There was no active TB disease among exposed newborns and HCWs during a one-year follow-up.

CONCLUSION

Timely diagnosis of congenital TB is crucial for minimizing transmission among exposed neonates and HCWs in the NICU setting. In cases of isoniazid-resistant index patients, even premature newborns may consider the use of rifampin or levofloxacin for window prophylaxis.

"Primer shot" fractionation with an early treatment break is theoretically superior to consecutive weekday fractionation schemes for early-stage non-small cell lung cancer

PURPOSE

Radiotherapy is traditionally given in equally spaced weekday fractions. We hypothesize that heterogeneous interfraction intervals can increase radiosensitivity via reoxygenation. Through modeling, we investigate whether this minimizes local failures and toxicity for early-stage non-small cell lung cancer (NSCLC).

METHODS

Previously, a tumor dose-response model based on resource competition and cell-cycle-dependent radiosensitivity accurately predicted local failure rates for early-stage NSCLC cohorts. Here, the model mathematically determined non-uniform inter-fraction intervals minimizing local failures at similar normal tissue toxicity risk, i.e., iso-BED3 (iso-NTCP) for fractionation schemes 18Gyx3, 12Gyx4, 10Gyx5, 7.5Gyx8, 5Gyx12, 4Gyx15. Next, we used these optimized schedules to reduce toxicity risk (BED3) while maintaining stable local failures (TCP).

RESULTS

Optimal schedules consistently favored a "primer shot" fraction followed by a 2-week break, allowing tumor reoxygenation. Increasing or decreasing the assumed baseline hypoxia extended or shortened this optimal break by up to one week. Fraction sizes of 7.5 Gy and up required a single primer shot, while smaller fractions needed one or two extra fractions for full reoxygenation. The optimized schedules, versus consecutive weekday fractionation, predicted absolute LF reductions of 4.6%-7.4%, except for the already optimal LF rate seen for 18Gyx3. Primer shot schedules could also reduce BED3 at iso-TCP with the biggest improvements for the shortest schedules (94.6Gy reduction for 18Gyx3).

CONCLUSION

A validated simulation model clearly supports non-standard "primer shot" fractionation, reducing the impact of hypoxia-induced radioresistance. A limitation of this study is that primer-shot fractionation is outside prior clinical experience and therefore will require clinical studies for definitive testing.

Biomechanical Comparison of Double 2.3-mm Headless Cannulated Self-Compression Screws and Single 3.5-mm Cortical Screw in Lag Fashion in a Canine Sacroiliac Luxation Model: A Small Dog Cadaveric Study

OBJECTIVE

 The aim of this study was to evaluate the feasibility of safe positioning of double 2.3-mm headless cannulated self-compression screws (HCS) in a small dog cadaveric sacroiliac luxation model and to compare the static rotational biomechanical properties of fixation repaired using two different screw systems with a minimally invasive osteosynthesis technique: double 2.3-mm HCS and a single 3.5-mm standard cortical screw placed in a lag fashion.

STUDY DESIGN

 A unilateral small dog sacroiliac luxation model was stabilized using double 2.3-mm HCS (n = 11) or a single 3.5-mm cortical screw (n = 11). Radiographic and computed tomography (CT) imaging analyses and biomechanical testing of rotational force on the sacroiliac joint of both fixations were performed. The maximum load at failure and failure modes of each fixation were recorded and compared.

RESULTS

 Fluoroscopically guided percutaneous application of double HCS was safe in a unilateral sacroiliac luxation model in small dogs without violation of the vertebral and ventral sacral foramen. Furthermore, resistance to rotational force applied on fixation of the sacroiliac joint repaired with double 2.3-mm HCS estimated by maximum failure load was significantly higher than that of a single 3.5-mm cortical screw (p < 0.001).

CONCLUSION

 Although this was an experimental cadaveric study, based on our results, the use of smaller double HCS may be beneficial as an alternative to the conventional single lag screw for stabilization of sacroiliac luxation in small dogs.

Standardized image-based polysomnography database and deep learning algorithm for sleep-stage classification

STUDY OBJECTIVES

Polysomnography (PSG) scoring is labor-intensive, subjective, and often ambiguous. Recently several deep learning (DL) models for automated sleep scoring have been developed, they are tied to a fixed amount of input channels and resolution. In this study, we constructed a standardized image-based PSG dataset in order to overcome the heterogeneity of raw signal data obtained from various PSG devices and various sleep laboratory environments.

METHODS

All individually exported European data format files containing raw signals were converted into images with an annotation file, which contained the demographics, diagnoses, and sleep statistics. An image-based DL model for automatic sleep staging was developed, compared with a signal-based model, and validated in an external dataset.

RESULTS

We constructed 10253 image-based PSG datasets using a standardized format. Among these, 7745 diagnostic PSG data were used to develop our DL model. The DL model using the image dataset showed similar performance to the signal-based dataset for the same subject. The overall DL accuracy was greater than 80%, even with severe obstructive sleep apnea. Moreover, for the first time, we showed explainable DL in the field of sleep medicine as visualized key inference regions using Eigen-class activation maps. Furthermore, when a DL model for sleep scoring performs external validation, we achieved a relatively good performance.

CONCLUSIONS

Our main contribution demonstrates the availability of a standardized image-based dataset, and highlights that changing the data sampling rate or number of sensors may not require retraining, although performance decreases slightly as the number of sensors decreases.

Human chemically-derived hepatic progenitors (hCdHs) as a source of liver organoid generation: Application in regenerative medicine, disease modeling, and toxicology testing

BACKGROUND & AIMS

Several types of human stem cells from embryonic (ESCs) and induced pluripotent (iPSCs) to adult tissue-specific stem cells are commonly used to generate 3D liver organoids for modeling tissue physiology and disease. We have recently established a protocol for direct conversion of primary human hepatocytes (hPHs) from healthy donor livers into bipotent progenitor cells (hCdHs). Here we extended this culture system to generate hCdH-derived liver organoids for diverse biomedical applications.

METHODS

To obtain hCdHs, hPHs were cultured in reprogramming medium containing A83-01 and CHIR99021 for 7 days. Liver organoids were established from hCdHs (hCdHOs) and human liver cells (hLOs) using the same donor livers for direct comparison, as well as from hiPSCs. Organoid properties were analyzed by standard in vitro assays. Molecular changes were determined by RT-qPCR and RNA-seq. Clinical relevance was evaluated by transplantation into FRG mice, modeling of alcohol-related liver disease (ARLD), and in vitro drug-toxicity tests.

RESULTS

hCdHs were clonally expanded as organoid cultures with low variability between starting hCdH lines. Similar to the hLOs, hCdHOs stably maintained stem cell phenotype based on accepted criteria. However, hCdHOs had an advantage over hLOs in terms of EpCAM expression, efficiency of organoid generation and capacity for directed hepatic differentiation as judged by molecular profiling, albumin secretion, glycogen accumulation, and CYP450 activities. Accordingly, FRG mice transplanted with hCdHOs survived longer than mice injected with hLOs. When exposed to ethanol, hCdHOs developed stronger ARLD phenotype than hLOs as evidenced by transcriptional profiling, lipid accumulation and mitochondrial dysfunction. In drug-induced injury assays in vitro, hCdHOs showed a similar or higher sensitivity response than hPHs.

CONCLUSION

hCdHOs provide a novel patient-specific stem cell-based platform for regenerative medicine, toxicology testing and modeling liver diseases.

A Cell-Penetrant Peptide Disrupting the Transcription Factor CP2c Complexes Induces Cancer-Specific Synthetic Lethality

Despite advances in precision oncology, cancer remains a global public health issue. In this report, proof-of-principle evidence is presented that a cell-penetrable peptide (ACP52C) dissociates transcription factor CP2c complexes and induces apoptosis in most CP2c oncogene-addicted cancer cells through transcription activity-independent mechanisms. CP2cs dissociated from complexes directly interact with and degrade YY1, leading to apoptosis via the MDM2-p53 pathway. The liberated CP2cs also inhibit TDP2, causing intrinsic genome-wide DNA strand breaks and subsequent catastrophic DNA damage responses. These two mechanisms are independent of cancer driver mutations but are hindered by high MDM2 p60 expression. However, resistance to ACP52C mediated by MDM2 p60 can be sensitized by CASP2 inhibition. Additionally, derivatives of ACP52C conjugated with fatty acid alone or with a CASP2 inhibiting peptide show improved pharmacokinetics and reduced cancer burden, even in ACP52C-resistant cancers. This study enhances the understanding of ACP52C-induced cancer-specific apoptosis induction and supports the use of ACP52C in anticancer drug development.

Widespread 8-oxoguanine modifications of miRNA seeds differentially regulate redox-dependent cancer development

Oxidative stress contributes to tumourigenesis by altering gene expression. One accompanying modification, 8-oxoguanine (o8G) can change RNA-RNA interactions via o8G•A base pairing, but its regulatory roles remain elusive. Here, on the basis of o8G-induced guanine-to-thymine (o8G > T) variations featured in sequencing, we discovered widespread position-specific o8Gs in tumour microRNAs, preferentially oxidized towards 5' end seed regions (positions 2-8) with clustered sequence patterns and clinically associated with patients in lower-grade gliomas and liver hepatocellular carcinoma. We validated that o8G at position 4 of miR-124 (4o8G-miR-124) and 4o8G-let-7 suppress lower-grade gliomas, whereas 3o8G-miR-122 and 4o8G-let-7 promote malignancy of liver hepatocellular carcinoma by redirecting the target transcriptome to oncogenic regulatory pathways. Stepwise oxidation from tumour-promoting 3o8G-miR-122 to tumour-suppressing 2,3o8G-miR-122 occurs and its specific modulation in mouse liver effectively attenuates diethylnitrosamine-induced hepatocarcinogenesis. These findings provide resources and insights into epitranscriptional o8G regulation of microRNA functions, reprogrammed by redox changes, implicating its control for cancer treatment.

Biomechanical Comparison between Inverted Triangle and Vertical Configurations of Three Kirschner Wires for Femoral Neck Fracture Fixation in Dogs: A Cadaveric Study

The purpose of this study was to compare single-cycle axial load and stiffness between inverted triangle and vertical configurations of three Kirschner wires (K-wires) for femoral neck fracture fixation in small dog cadaveric models. In each of the eight cadavers, the basilar femoral neck fracture model was prepared on both sides of the femur. One side of the femur was stabilized with three 1.0 mm K-wires of an inverted triangle configuration (group T), and the other femur was stabilized with a vertical configuration (group V). Postoperatively, the placement of the K-wires was evaluated with radiographic and computed tomography (CT) images, and static vertical compressive loading tests were performed. The mean yield load and the lateral spread were significantly higher in group T compared to group V (p = 0.023 and <0.001). On the cross-section of femoral neck at the level of the fracture line, the surface area between K-wires was significantly larger (p < 0.001) and the mean number of cortical supports was significantly higher in group T (p = 0.007). In this experimental comparison, the inverted triangle configuration of three K-wires was more resistant to failure under axial loading than the vertical configuration for canine femoral neck fracture fixation.

Use of Computed Tomography and Magnetic Resonance Angiograms Combined with a 3D Surgical Guide in an Elderly Cat with an Occipital Lobe Meningioma

We present a case of occipital lobe meningioma resection in an elderly cat. The surgery was performed with the goal of avoiding major bleeding. An 11-year-old castrated indoor-only male Persian Chinchilla (5.5 kg) was presented with a month-long history of progressive tetraparesis for a left occipital lobe meningioma. Magnetic resonance imaging revealed a T2-weighted heterogeneously hyperintensity and a T1-weighted well-contrast enhancing extradural mass in the left occipital lobe of the brain. Cerebral angiographic data were obtained using magnetic resonance (MRA) and computed tomography angiography (CTA). Advanced angiograms and virtual reconstruction of images revealed that the tumor was surrounded by the caudal parasagittal meningeal vein. A left caudal rostrotentorial craniotomy and en bloc resection of the tumor were performed, and histopathology revealed a meningioma. Complete neurological recovery was achieved within 10 days after surgery. To the best of our knowledge, this is the first case report describing CTA and MRA findings and favorable clinical outcomes after surgical management of a brain meningioma without severe perioperative complications.

Bioengineered liver crosslinked with nano-graphene oxide enables efficient liver regeneration via MMP suppression and immunomodulation

Decellularized extracellular matrix scaffold, widely utilized for organ engineering, often undergoes matrix decomposition after transplantation and produces byproducts that cause inflammation, leading to clinical failure. Here we propose a strategy using nano-graphene oxide to modify the biophysical properties of decellularized liver scaffolds. Notably, we demonstrate that scaffolds crosslinked with nano-graphene oxide show high resistance to enzymatic degradation via direct inhibition of matrix metalloproteinase activity and increased mechanical rigidity. We find that M2-like macrophage polarization is promoted within the crosslinked scaffolds, which reduces graft-elicited inflammation. Moreover, we show that low activities of matrix metalloproteinases, attributed to both nano-graphene oxide and tissue inhibitors of metalloproteinases expressed by M2c, can protect the crosslinked scaffolds against in vivo degradation. Lastly, we demonstrate that bioengineered livers fabricated with the crosslinked scaffolds remain functional, thereby effectively regenerating damaged livers after transplantation into liver failure mouse models. Overall, nano-graphene oxide crosslinking prolongs allograft survival and ultimately improves therapeutic effects of bioengineered livers, which offer an alternative for donor organs.

Ex Vivo Base Editing Therapy with Chemically Derived Hepatic Progenitors

Ex vivo gene therapy through convergence study with progenitors and base/prime editors provides valuable approaches that can be utilized in the study and treatment of hereditary intractable diseases and models. Small molecule-mediated reprogramming of hepatocytes into bi-potent hepatic progenitors is a safe and efficient strategy for ex vivo gene therapy. Here, we described how to generate hepatic progenitors from terminally differentiated hepatocytes, deliver base/prime editors into the cells, select corrected hepatic progenitors, and transplant them into mice of inborn error of metabolism.

Case report: Block recession calcaneoplasty of the calcaneal tuber for treating lateral superficial digital flexor tendon luxation in a dog

A 4-year-old, intact, female, Collie was presented with 5 month history of right hindlimb lameness. Lateral luxation of the superficial digital flexor tendon (SDFT) was diagnosed on the basis of the clinical, radiographic and ultrasonographic finding. Intraoperatively, shallow right calcaneal tuber was observed. Block recession calcaneoplasty with retinaculum repair using anchor screw were performed to manage SDFT luxation. Additionally, temporary restraining pin was placed on lateral aspect of the calcaneal tuber. The patient demonstrated mild lameness at 2 weeks postoperatively and improved to normal limb function at 12 weeks postoperatively. As the gold standard of surgical techniques for SDFT luxation has not yet been reported, block recession calcaneooplasty may be an alternative surgical option for patients with calcaneal morphologic abnormalities causing SDFT luxation.

Novel transforaminal approach allows surgical decompression of an atlantoaxial band in dogs: a cadaveric study and clinical cases

OBJECTIVES

To describe a novel transforaminal approach for surgical excision of the atlantoaxial (AA) band and examine its feasibility, safety, and mechanical advantages in an ex vivo study and clinical cases.

SAMPLES

26 canine cadavers and 2 canine patients with AA bands.

PROCEDURES

The transforaminal approach via the first intervertebral foramen was designed to avoid damaging the dorsal AA ligament (DAAL) and dorsal laminas to maintain joint stability. The cadaveric study started on December 2020 and lasted 3 months. The ligamentum flavum (LF) was removed using a novel approach; then, gross examination was conducted to verify the potential damage to the spinal cord and associated structures and the adequacy of LF removal. Subsequently, the ex vivo tension test of the DAAL was conducted to establish whether the approach induced mechanical damage to the ligaments. Finally, 2 dogs diagnosed with an AA band were surgically treated with the transforaminal approach.

RESULTS

In the cadaveric study, postsurgical evaluation verified the subtotal removal of LF without damage to the dura mater. There were no significant differences in the mechanical properties of the DAAL, including the ultimate strength (P = .645) and displacement (P = .855), between the surgical and intact groups during the ex vivo tension test. In clinical cases, clinical signs and neurologic grades improved until the final follow-up.

CLINICAL RELEVANCE

The described surgical procedure using a transforaminal approach appears to sufficiently permit the removal of an AA band while reducing damage to the DAAL and spinal cord. Our study highlights the feasibility of the transforaminal approach.

Case report: Three-dimensionally printed patient-specific acetabular cage for revision surgery of aseptic loosening in a dog with micro total hip replacement

A 2-year-old castrated male Pomeranian dog was presented for regular follow-up after micro total hip replacement (mTHR) 16 months prior to presentation. Clinically, the dog did not show any noticeable lameness of the left hindlimb, except for external rotation during walking. However, radiographic findings, namely rotation and medialization of the acetabular cup with a periprosthetic lucent line and bone formation medial to the acetabulum, were interpreted as aseptic loosening of the acetabular component. Because the dog was incompatible with the conventional THR revision method owing to severe bone defects in the acetabulum, a patient-specific titanium acetabular cage prosthesis with biflanges and four cranial and one caudal screw hole was designed for revision surgery. A custom-made acetabular cage was prepared, and it had a 12-mm polyethylene cup fixed with polymethylmethacrylate bone cement and positioned in the acetabulum. After the custom-made acetabular cage was anchored to the pelvic bone with the five cortical screws, reduction of the prostheses was achieved smoothly. The dog showed almost normal limb function without external rotation of the left hindlimb 2 weeks postoperatively. Bone remodeling and stable implant position were noted on radiographic images 3 years after revision surgery, with no evidence of loosening. Based on the clinical outcomes, the use of a custom-made acetabular prosthesis can be an effective treatment option for revision arthroplasty in acetabula with severe bone loss and structural changes in small-breed dogs.

Late ventricular potential for risk prediction of sudden cardiac death risk: a valuable tool or an unnecessary step?

Background/Introduction

Signal-averaged electrocardiography (SA-ECG) is a high-resolution electrocardiography that can detect late ventricular potential, which known to be a noninvasive tool for risk stratification of sudden cardiac death (SCD) by predicting reentrant ventricular tachyarrhythmia. There is a paucity of data with SA-ECG on SCD survivors without structural heart disease, whereas majority of previous studies had been focused on post myocardial infarction survivors.

Purpose

This study assessed the clinical utility of SA-ECG as a risk stratification modality for lethal arrhythmic event in patients at risk of SCD without definite structural heart disease.

Methods

Total 629 patients who experienced or had potential risk of SCD were studied with SA-ECG. Among them, 48 patients who were found to have significant structural heart disease were excluded, except arrhythmogenic right ventricular cardiomyopathy. Major arrhythmic event (MAE) was defined as composite of all-cause death, aborted SCD, and sustained VT during any time either before visit of clinic or during follow up period. Syncope and non-sustained VT was defined as non-major arrhythmic event. SA-ECG was defined positive when fulfilling three or more criterion: (1) unfiltered QRS duration ≥114ms, (2) filtered QRS duration ≥114ms, (3) duration of terminal QRS &lt;40uV exceeding 40ms, and (4) root mean square voltage in the terminal 40ms of ≤20ms.

Results

Among total 581 patients, 145 patients with positive SA-ECG showed higher incidence of MAE compared to patients with negative SA-ECG (21.4% vs. 6.7%, OR 3.816 [95% CI 2.208–6.597], p&lt;0.001, Table). As the number of positive SA-ECG criteria increases, incidence of MAE tended to increase sequentially, which was markedly noted from 2 positive to 3 positive criteria (10.7% to 20.8%, p&lt;0.001, Figure). In particular, patient with inherited arrhythmia showed higher rate of positive late potential compared to those with non-inherited arrhythmia (51.0% vs. 19.3%, p&lt;0.001).

Conclusion

This study showed that at least 3 out of 4 diagnostic criteria in SA-ECG can independently predict lethal arrhythmic events and the positive late potential was associated with lethal arrhythmic event that leads to SCD, suggesting risk prediction for SCD using SA-ECG in patients even without structural heart disease including inherited arrhythmias.

Funding Acknowledgement

Type of funding sources: None.

Clinical role of genetic testing for overlapping between Brugada syndrome and arrhythmogenic right ventricular cardiomyopathy

Background/Introduction

Brugada syndrome (BrS) and arrhythmogenic right ventricular cardiomyopathy (ARVC) are inherited arrhythmias that may predispose to sudden cardiac arrest. Although its pathogenetic mechanisms differ, overlapping features between BrS and ARVC have been demonstrated previously. However, it remains to be determined whether genetic testing for ARVC-related gene is needed in patients with BrS.

Purpose

This study is aimed to analyze genetic profiles of BrS patients using next generation sequencing (NGS) based multigene panel including ARVC related genes.

Methods

Patients who were confirmed as BrS or clinically suspected as BrS with type 2 or 3 Brugada pattern electrocardiography were studied. Genetic testing using NGS panels (Illumina Inc., San Diego, CA, USA) included 30 genetic variants associated with inherited arrhythmia and genetic cardiomyopathy.

Results

Among the total 119 patients from BrS registry, 63 patients were confirmed as BrS and 56 patients were clinically suspected as BrS without fulfilling diagnostic criteria. One-hundred-fourteen patients (95.8%) were male, and mean age of onset was 43.6 year-old. Genetic variants were identified in 25 of 42 patients who received genetic testing. Six out of 25 patients (24.0%) showed ARVC-related genotypes (2 PKP2, 1 DSG2, 1 TMEM43, 1 JUP, and 1 DSP) (Figure 1 and Table 1). None of the patients showed structural or electrocardiographic features that fulfill diagnostic criteria of ARVC. It is notable that ARVC-related genotypes were mostly frequently accounted for BrS patients, following SCN5A and SCN10A.

Conclusion

In the clinic setting, ARVC-related genetic variants were identified in significant proportion of BrS patients, supporting that genetic testing of ARVC-overlapping is needed. This study suggests that follow-up including imaging study should be considered in BrS patients with ARVC-related genotypes to monitor disease progression as ARVC.

Funding Acknowledgement

Type of funding sources: None.

Multiple Meningioma Resection by Bilateral Extended Rostrotentorial Craniotomy with a 3D-Print Guide in a Cat

Simple Summary

Meningioma is the most common intracranial neoplasia in cats. Treatments for meningiomas—including complete surgical resection, debulking, irradiation, or palliative therapy—have been reported in veterinary medicine. However, multiple meningiomas (two or more meningiomas in the same patient, separated by anatomical location) have been reported to affect the complication rate and prognosis. Moreover, the characteristics of neurosurgery—such as accurate localization and awareness of the anatomical structures of the lesions—make the surgery especially difficult for inexperienced surgeons. Surgical navigation systems have been developed, but recently, patient-specific three-dimensional(3D)-printed models and guides have also been used in orthopedics and neurosurgeries for treating many disorders with good results. A 13-year-old castrated male domestic shorthair cat was referred with multiple meningiomas located within the right frontal and occipital lobes. The cat suffered from generalized tonic–clonic seizures and mild proprioceptive ataxia. After removing both of the tumors, the cat showed a favorable clinical outcome and no neurological abnormalities throughout long-term follow-up. With a patient-specific 3D guide technology, a craniotomy for multiple meningiomas can be performed safely and accurately.

Abstract

A 13-year-old castrated male domestic shorthair cat was referred for the surgical removal of multiple meningiomas. The cat experienced generalized tonic–clonic seizures, altered mentation, mild proprioceptive ataxia, and circling. Magnetic resonance imaging (MRI) revealed two round, solitary, well-delineated, space-occupying lesions suggestive of multiple meningiomas in the right frontal and occipital lobes. Before surgery, patient-specific three-dimensional (3D) printed models and guides were produced using a 3D program based on MRI and computed tomography (CT), and a rehearsal surgery was performed. With a 3D guide to find the location of the craniotomy lines, bilateral extended rostrotentorial craniotomy allowed en bloc resection of multiple meningiomas. The bone fragment was replaced and secured to the skull with a craniofacial plate and screws with an artificial dura. All of the surgical steps were performed without complications. The preoperative presenting signs were resolved by the time of follow-up examinations 2 weeks after surgery. Twelve months after the removal of the multiple meningiomas, the cat survived without further neurological progression. For the resection of multiple meningiomas, surgery can result in large bone defects and risk of massive hemorrhage. For this challenging surgery, patient-specific 3D models and guides can be effective for accurate and safe craniotomies.

Case report: Primary chronic calcaneal bursitis treated with subtotal bursectomy in a cat

A 6-year-old, female spayed Bengal cat with a bodyweight of 6.4 kg was presented with swelling of the bilateral calcaneal region and weight-bearing hindlimb lameness with a 4-month history of unsuccessful conservative therapy. On orthopedic examination, a cyst-like mass around the calcaneal tendon was palpated. Palpating the mass and flexing the tarsal joint triggered pain. Through ultrasonography and magnetic resonance imaging, an inflamed or fluid-accumulated lesion was suspected around the calcaneal tendon, but there was no evidence of calcaneal tendonitis. Swollen calcaneal bursae were removed surgically. Histopathologic examination revealed fibrosis and an edematous feature. The cat was diagnosed with bilateral chronic primary calcaneal bursitis based on history, clinical signs, and diagnostic results. Hence, subtotal bursectomy was performed. At 4 weeks postoperatively, the cat had no pain around the tarsal joints and was ambulating normally. Radiographic and ultrasonographic exams revealed no recurrence of swelling or inflammation in the calcaneal region. Thirteen-month follow-up confirmed acceptable function and no relapse of clinical signs. The inflammation of calcaneal bursa alone can be the primary cause of hindlimb lameness in cats. A cat with hindlimb lameness and swelling on the calcaneal region should be assessed with the possibility of primary calcaneal bursitis. Subtotal calcaneal bursectomy can be considered as an effective treatment for primary chronic bursitis.

Therapeutic applications of gene editing in chronic liver diseases: an update

Innovative genome editing techniques developed in recent decades have revolutionized the biomedical research field. Liver is the most favored target organ for genome editing owing to its ability to regenerate. The regenerative capacity of the liver enables ex vivo gene editing in which the mutated gene in hepatocytes isolated from the animal model of genetic disease is repaired. The edited hepatocytes are injected back into the animal to mitigate the disease. Furthermore, the liver is considered as the easiest target organ for gene editing as it absorbs almost all foreign molecules. The mRNA vaccines, which have been developed to manage the COVID-19 pandemic, have provided a novel gene editing strategy using Cas mRNA. A single injection of gene editing components with Cas mRNA is reported to be efficient in the treatment of patients with genetic liver diseases. In this review, we first discuss previously reported gene editing tools and cases managed using them, as well as liver diseases caused by genetic mutations. Next, we summarize the recent successes of ex vivo and in vivo gene editing approaches in ameliorating liver diseases in animals and humans.

UPF1 Inhibits Hepatocellular Carcinoma Growth through DUSP1/p53 Signal Pathway

Human hepatocellular carcinoma (HCC) has a high mortality rate because of the dearth of effective treatments. Multiple studies have shown that overexpression of UPF1, a key nonsense-mediated mRNA decay (NMD) factor, reduces HCC growth through various cell signaling pathways. However, the mechanism by which UPF1 expression retards HCC proliferation through the regulation of RNA stability remains unclear. By employing various UPF1 variants and transcriptome analysis, we revealed that overexpression of UPF1 variants, not UPF1-mediated NMD, reduces HCC tumorigenesis. Additionally, UPF1 variant overexpression reduced tumorigenesis in xenografted mice. Transcriptome analysis indicated that the level of dual specificity phosphatase 1 (DUSP1) was increased by UPF1 variants via posttranscriptional regulation. The UPF1 overexpression-mediated increase of DUSP1 activated tumor suppressor signaling, ultimately inhibiting cell growth. In this study, we highlighted the function of UPF1 as a tumor suppressor in HCC growth.

Extended DeepILST for Various Thermodynamic States and Applications in Coarse-Graining

Molecular dynamics (MD) simulations are widely used to obtain the microscopic properties of atomistic systems when the interatomic potential or the coarse-grained potential is known. In many practical situations, however, it is necessary to predict the interatomic or coarse-grained potential, which is a tremendous challenge. Many approaches have been developed to predict the potential parameters based on various techniques, including the relative entropy method, integral equation theory, etc., but these methods lack transferability and are limited to a specific range of thermodynamic states. Recently, data-driven and machine learning approaches have been developed to overcome such limitations. In this study, we expand the range of thermodynamic states used to train deep inverse liquid-state theory (DeepILST)¹, a deep learning framework for solving the inverse problem of liquid-state theory. We also assess the performance of DeepILST in coarse-graining various multiatom molecules and identify the molecular characteristics that affect the coarse-graining performance of DeepILST.

Comparative Analysis of the National Fatality Rate in Construction Industry Using Time-Series Approach and Equivalent Evaluation Conditions

Fatality rates such as fatalities per full-time equivalent workers are officially used to compare the risk level of the construction industry among various countries. However, each country evaluates the fatality rate using different conditions. This paper presents the comparison of fatality rates of various countries using conventional (national data) and pair (equivalent condition) methods through a time-series approach. The research was conducted in three stages. The risk level was evaluated in order in South Korea (1.54), Japan (0.84), Mexico (0.83), China (0.70), United Kingdom (0.15), and Singapore (0.13) in terms of national data. However, the risk level was re-evaluated in order in China (2.27), South Korea (2.05), Mexico (1.23), Singapore (0.98), Japan (0.80), and United Kingdom (0.47) in terms of equivalent conditions. The risk level of each can be changed when the fatality rate is compared under given equivalent conditions.

Deep Learning Application to Clinical Decision Support System in Sleep Stage Classification

Recently, deep learning for automated sleep stage classification has been introduced with promising results. However, as many challenges impede their routine application, automatic sleep scoring algorithms are not widely used. Typically, polysomnography (PSG) uses multiple channels for higher accuracy; however, the disadvantages include a requirement for a patient to stay one or more nights in the lab wearing uncomfortable sensors and wires. To avoid the inconvenience caused by the multiple channels, we aimed to develop a deep learning model for use in clinical decision support systems (CDSSs) and combined convolutional neural networks and a transformer for the supervised learning of three classes of sleep stages only with single-channel EEG data (C4-M1). The data for training, validation, and test were derived from 1590, 341, and 343 polysomnography recordings, respectively. The developed model yielded an overall accuracy of 91.4%, comparable with that of human experts. Based on the severity of obstructive sleep apnea, the model’s accuracy was 94.3%, 91.9%, 91.9%, and 90.6% in normal, mild, moderate, and severe cases, respectively. Our deep learning model enables accurate and rapid delineation of three-class sleep staging and could be useful as a CDSS for application in real-world clinical practice.

Transplantation of patient-specific bile duct bioengineered with chemically reprogrammed and microtopographically differentiated cells

Cholangiopathy is a diverse spectrum of chronic progressive bile duct disorders with limited treatment options and dismal outcomes. Scaffold- and stem cell-based tissue engineering technologies hold great promise for reconstructive surgery and tissue repair. Here, we report a combined application of 3D scaffold fabrication and reprogramming of patient-specific human hepatocytes to produce implantable artificial tissues that imitate the mechanical and biological properties of native bile ducts. The human chemically derived hepatic progenitor cells (hCdHs) were generated using two small molecules A83-01 and CHIR99021 and seeded inside the tubular scaffold engineered as a synergistic combination of two layers. The inner electrospun fibrous layer was made of nanoscale-macroscale polycaprolactone fibers acting to promote the hCdHs attachment and differentiation, while the outer microporous foam layer served to increase mechanical stability. The two layers of fiber and foam were fused robustly together thus creating coordinated mechanical flexibility to exclude any possible breaking during surgery. The gene expression profiling and histochemical assessment confirmed that hCdHs acquired the biliary epithelial phenotype and filled the entire surface of the fibrous matrix after 2 weeks of growth in the cholangiocyte differentiation medium in vitro. The fabricated construct replaced the macroscopic part of the common bile duct (CBD) and re-stored the bile flow in a rabbit model of acute CBD injury. Animals that received the acellular scaffolds did not survive after the replacement surgery. Thus, the artificial bile duct constructs populated with patient-specific hepatic progenitor cells could provide a scalable and compatible platform for treating bile duct diseases.

Generation and differentiation of chemically derived hepatic progenitors from mouse primary hepatocytes

This protocol describes the generation of bipotent chemically derived hepatic progenitors (mCdHs) from mouse primary hepatocytes and their subsequent differentiation into either hepatic or cholangiocytic lineages. The reprogrammed mCdHs have a high proliferation capacity and express progenitor markers in long-term passages. Differentiated mCdHs show the characteristics of either hepatic or cholangiocytic genes. This protocol has potential application for regenerative medicine, including ex vivo gene therapy, disease modeling, drug screening, and personalized medicine. For complete details on the use and execution of this protocol, please refer to Kim et al. (2021).

Fate and transport in environmental quality

Changes in pollutant concentrations in environmental media occur both from pollutant transport in water or air and from local processes, such as adsorption, degradation, precipitation, straining, and so on. The terms "fate and transport" and "transport and fate" reflect the coupling of moving with the carrier media and biogeochemical processes describing local transformations or interactions. The Journal of Environmental Quality (JEQ) was one of the first to publish papers on fate and transport (F&T). This paper is a minireview written to commemorate the 50th anniversary of JEQ and show how the research interests, methodology, and public attention have been reflected in fate and transport publications in JEQ during the last 40 years. We report the statistics showing how the representation of different pollutant groups in papers changed with time. Major focus areas have included the effect of solution composition on F&T and concurrent F&T, the role of organic matter, and the relative role of different F&T pathways. The role of temporal and spatial heterogeneity has been studied at different scales. The value of long-term F&T studies and developments in modeling as the F&T research approach was amply demonstrated. Fate and transport studies have been an essential part of conservation measure evaluation and comparison and ecological risk assessment. For 50 years, JEQ has delivered new insights, methods, and applications related to F&T science. The importance of its service to society is recognized, and we look forward to new generations of F&T researchers presenting their contributions in JEQ.

Association of Microbial Dysbiosis with Gallbladder Diseases Identified by Bile Microbiome Profiling

BACKGROUND

Cholecystitis is an important risk factor for gallbladder cancer, but the bile microbiome and its association with gallbladder disease has not been investigated fully. We aimed to analyze the bile microbiome in normal conditions, chronic cholecystitis, and gallbladder cancer, and to identify candidate bacteria that play an important role in gallbladder carcinogenesis.

METHODS

We performed metagenome sequencing on bile samples of 10 healthy individuals, 10 patients with chronic cholecystitis, and 5 patients with gallbladder cancer, and compared the clinical, radiological, and pathological characteristics of the participants.

RESULTS

No significant bacterial signal was identified in the normal bile. The predominant dysbiotic bacteria in both chronic cholecystitis and gallbladder cancer were those belonging to the Enterobacteriaceae family. Klebsiella increased significantly in the order of normal, chronic cholecystitis, and gallbladder cancer. Patients with chronic cholecystitis and dysbiotic microbiome patterns had larger gallstones and showed marked epithelial atypia, which are considered as precancerous conditions.

CONCLUSION

We investigated the bile microbiome in normal, chronic cholecystitis, and gallbladder cancer. We suggest possible roles of Enterobacteriaceae, including Klebsiella, in gallbladder carcinogenesis. Our findings reveal a possible link between a dysbiotic bile microbiome and the development of chronic calculous cholecystitis and gallbladder cancer.

Exploring Fatalities and Injuries in Construction by Considering Thermal Comfort Using Uncertainty and Relative Importance Analysis

Fatal injury and accidents in the construction industry occur under the influence of outdoor weather conditions such as temperature, humidity and wind speed in all four seasons. Previous research in this area has focused on hot and cold weather conditions: hot weather causes heat rash, heat cramps and heat fainting, while cold weather causes fatigue, lumbago, and cold finger sensations. However, other weather conditions are also associated with, and cause, fatal injury and accidents. Accordingly, this study analyzes injury and fatal accidents in the construction industry based on the physiological equivalent temperature (PET) as it pertains to thermal comfort using an uncertainty analysis. Furthermore, using a neural network, relative importance is analyzed considering injury and fatal accidents. This study is conducted in five steps: (i) Establishment of the database, (ii) Classification of accident types and weather conditions, (iii) Calculation of thermal comfort, (iv) Analysis of injury and fatal accidents based on thermal comfort, and (v) Calculation of the relative importance of thermal comfort during injury and fatal accidents. Via the research process, 5317 fatal incidents and 207,802 injuries are analyzed according to 18 accident types in all seasons. It was found that 'falls', were the most frequent fatal incident and injury (2804 fatal incidents and 71,017 injuries), with most of these occurring during the autumn season. The probabilities of injury and fatal accidents in the 'fall' category are 86.01% and 85.60%, respectively, in the outside comfort ranges. The contribution of this study can provide data for a database on safety management considering weather conditions.

Hepatic patch by stacking patient-specific liver progenitor cell sheets formed on multiscale electrospun fibers promotes regenerative therapy for liver injury

Recently, use of cell sheets with bio-applicable fabrication materials for transplantation has been an attractive approach for the treatment of patients with liver failure. However, renewable and scalable cell sources for engineered tissue patches remain limited. We previously reported a new type of proliferating bipotent human chemically derived hepatic progenitor cells (hCdHs) developed by small molecule-mediated reprogramming. Here, we developed a patient-specific hepatic cell sheet constructed from liver biopsy-derived hCdHs on a multiscale fibrous scaffold by combining electrospinning and three-dimensional printing. Analysis of biomaterial composition revealed that the high-density electrospun sheet was superior in increasing the functional properties of hCdHs. Furthermore, the hepatic patch assembled by multilayer stacking with alternate cell sheets of hCdHs and human umbilical vein endothelial cells (HUVECs) recapitulated a liver tissue-like structure, with histological and morphological shape and size similar to those of primary human hepatocytes, and exhibited a significant increase in hepatic functions such as albumin secretion and activity of cytochrome P450 during in vitro hepatic differentiation compared with that in hCdH cells cultured in a two-dimensional monolayer. Interestingly, in the hepatic patch, the induction of functional hepatocytes was associated with both the electrospun fibrous-facilitated oncostatin M signaling and selective activation of AKT signaling by HUVECs. Notably, upon transplantation into a mouse model of therapeutic liver repopulation, the hepatic patch effectively repopulated the damaged parenchyma and induced the restoration of liver function with healthy morphology in the lobe and an improved survival rate (>70%) in mice. Overall, these results suggested that liver biopsy-derived hCdHs can be an efficient alternative source for developing hepatic cell sheets and patches with potential clinical applications in tissue engineering to advance liver regeneration.

Subsequent meniscal tears following tibial tuberosity advancement and tibial plateau leveling osteotomy in dogs with cranial cruciate ligament deficiency: An in vivo experimental study

OBJECTIVE

To evaluate the short- and mid-term effects of tibial tuberosity advancement (TTA) and tibial plateau leveling osteotomy (TPLO) on subsequent meniscal tears.

STUDY DESIGN

Experimental in vivo study.

ANIMALS

Purpose-bred beagle dogs (n = 15).

METHODS

For each dog, the cranial cruciate ligaments were transected; one limb underwent TTA and the other limb underwent TPLO. Orthopedic and radiographic examinations were performed preoperatively and at 12 and 32 weeks postoperatively. Gross evaluation of the stifle joint was performed after euthanasia at 12 (n = 10) and 32 (n = 5) weeks.

RESULTS

Lameness scores were not different between TTA and TPLO limbs at any time point. Radiographic osteoarthritis scores of TTA stifles (1.33 ± 0.49) were higher than TPLO stifles (0.67 ± 0.49) (p = .002) at 12 weeks postoperatively, but there was no difference between groups at 32 weeks postoperatively. Subsequent medial meniscal tears occurred in 6/10 TTA stifles, and 0/10 TPLO stifles at 12 weeks postoperatively and in 5/5 TTA stifles, and 1/5 TPLO stifles at 32 weeks postoperatively. Subsequent lateral meniscal tears occurred in 4/5 TTA stifles at 32 weeks postoperatively. Medial meniscal total gross pathology score was higher in TTA than TPLO stifles. TTA stifles had more articular cartilage damage when compared with TPLO stifles at 32 weeks postoperatively.

CONCLUSION

In this within-dog experimental comparison, subsequent medial meniscal tears and cartilage injury was more prevalent following TTA when compared to TPLO.

CLINICAL SIGNIFICANCE

In an experimental model, TPLO protects the medial meniscus and articular cartilage better than TTA in stifles with complete cranial cruciate ligament deficiency.

97 Function of species-specific OCT4 reporter system during porcine embryo development

The present study examined the activity and function of pig OCT4 (POU5F1) enhancer in porcine early embryo development. OCT4 is one of the master regulators for the pluripotency of early mammalian embryonic development and embryonic stem cells. It has two regulatory elements: distal enhancer (DE) and proximal enhancer (PE) in the upstream regulatory region. They are activated under different conditions such as naïve and primed. It is known that two enhancers are activated to produce OCT4 simultaneously or sequentially depending on the state of pluripotency. Many porcine OCT4 upstream region-based reporter systems have been reported because this is a necessary part of studying porcine-specific pluripotency. However, the porcine-specific OCT4 reporter system has never been transfected and functionally tested during porcine early embryo development. We performed functional tests of the previously established porcine-specific OCT4 reporter system in the early embryo development stage. Porcine embryos were micro-injected with the pOCT4-ΔPE-eGFP (DE-GFP) containing a distal enhancer and core promoter and pOCT4-ΔDE-DsRed2 (PE-RFP) containing a proximal enhancer and core promoter. They were cultured in PZM-3 at 39°C in a humidified atmosphere, 5% CO2, and 5% O2 for 168h. Fifty of the 100 embryos were injected with OCT4 reporter system as treatment groups and the other 50 were not injected (control groups). We analysed mRNA and protein expression of GFP and RFP using quantitative real-time PCR and confocal microscopy by developmental stages. The introduced reporter system could function beginning with the 4-cell stage. The expression of GFP and RFP was observed simultaneously in the early embryonic development stage up to blastocyst, indicating that porcine OCT4 was produced by distal and proximal enhancers, unlike mouse Oct4 expression, which was only controlled by the distal enhancer during early embryo development. Therefore, the mechanisms and functions of distal and proximal enhancers of porcine OCT4 were different from those of the mouse. This is similar to results of the previous experiment using porcine-induced pluripotent stem cells, which suggest that porcine OCT4 is expressed by two enhancers and in a stage-specific manner during reprogramming and that pigs do not use only one enhancer in pluripotent states, but two enhancers at the same time, and there is only a difference in degree. This work showed that the porcine OCT4 reporter system enables non-destructive analysis during early embryo development and it could be applied to study species-specific pluripotency and to help the establishment of naïve embryonic stem cells in the pig. This work was supported by the BK21 Plus Program, the National Research Foundation of Korea (NRF) grant funded by the Korea government (NRF-2019R1C1C1004514), the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) through the Development of High Value-Added Food Technology Program funded by the Ministry of Agriculture, Food, and Rural Affairs (MAFRA; 118042-03-3-HD020).

42 Disruption of endogenous SOX2 during porcine embryo development using the CRIPSR/Cas9 system

The lineage specification of the pre-implantation embryo is important to understand the developmental process, but it remains unclear because the expression of lineage-specific genes is distinct among species. Pigs have genetic and physiological traits similar to humans; however, there are differences in gene expression during the pre-implantation stage. To select a candidate gene that affects the formation of the inner cell mass (ICM) in porcine embryo, we conducted preliminary experiments. First, we measured the expression level of candidate genes for lineage specification in parthenogenetic-activated embryos. The expression of pluripotent genes peaked on Day 3 and thereafter decreased gradually. Next, we conducted immunocytochemistry. OCT4 was expressed in all cells in morula and Day 5 blastocyst, but some Day 7 blastocysts expressed OCT4 in both ICM and trophectoderm (TE), whereas others expressed OCT4 only in ICM. NANOG was not observed in the morula stage, whereas SOX2 was located in a restricted area. To examine the effect of SOX2 in ICM formation, we injected plasmid expressing Cas9 and guide (g)RNA using Lipofectamine for efficient transgene expression at the 2-cell stage to increase viability by inducing mosaicism. The expression of enhanced green fluorescent protein (EGFP) contained in the plasmid confirmed that the plasmid was operating normally. In SOX2-knockout (KO) early blastocysts, the numbers of total cells and SOX2- and NANOG-positive cells were greatly decreased, while OCT4 was expressed in most cells. As in early blastocysts, SOX2-KO late blastocysts had fewer cells expressing SOX2, NANOG, and SOX17 than control. To identify the transcriptional consequences of SOX2 reduction, we performed quantitative PCR analysis on non-injected and PX458-gRNA injected blastocysts. Injection of PX458-gRNA resulted in downregulation of NANOG, SOX17, and SMAD7, but not SOX2 and OCT4. Furthermore, proliferation-associated genes were downregulated in injected blastocysts. In conclusion, SOX2-targeted porcine embryos showed blastocoel formation, the inner cell mass formed poorly, and embryos have inefficient cells. Also, the depletion of SOX2 in porcine blastocysts downregulated pluripotent genes and proliferation genes. This work was supported by the BK21 Plus Program, the National Research Foundation of Korea (NRF) grant funded by the Korea government (NRF-2019R1C1C1004514), the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) through the Development of High Value-Added Food Technology Program funded by the Ministry of Agriculture, Food, and Rural Affairs (MAFRA; 118042-03-3-HD020).