Engineered ionizable lipid nanoparticles for targeted delivery of RNA therapeutics into different types of cells in the liver

Ionizable lipid nanoparticles (LNPs) have been widely used for in vivo delivery of RNA therapeutics into the liver. However, a main challenge remains to develop LNP formulations for selective delivery of RNA into certain types of liver cells, such as hepatocytes and liver sinusoidal endothelial cells (LSECs). Here, we report the engineered LNPs for the targeted delivery of RNA into hepatocytes and LSECs. The effects of particle size and polyethylene glycol-lipid content in the LNPs were evaluated for the hepatocyte-specific delivery of mRNA by ApoE-mediated cellular uptake through low-density lipoprotein receptors. Targeted delivery of RNA to LSECs was further investigated using active ligands. Incorporation of mannose allowed the selective delivery of RNA to LSECs, while minimizing the unwanted cellular uptake by hepatocytes. These results demonstrate that engineered LNPs have great potential for the cell type-specific delivery of RNA into the liver and other tissues.

Developing a predictive model for distinguishing invasive nail unit melanoma from nail unit melanoma in situ

BACKGROUND

Clinical information that distinguishes invasive nail unit melanoma from nail unit melanoma in situ before surgery would aid physicians in the decision-making process and estimating prognosis. However, limited information is available on the detailed demographic and dermoscopic features of invasive nail unit melanoma and nail unit melanoma in situ for differential diagnosis.

OBJECTIVE

This study aimed to investigate the demographic data and dermoscopic features of invasive nail unit melanoma and nail unit melanoma in situ and establish a predictive model for differentiating these two forms of nail unit melanoma.

METHODS

A retrospective observational study of ninety-seven patients diagnosed with nail unit melanoma (59 in situ and 38 invasive cases) in four healthcare centres in South Korea (three tertiary referral hospitals and one second referral hospital) from March 2014 to December 2019.

RESULTS

A multivariable analysis revealed that ulcer (odds ratio = 21.6, confidence interval = 2.1-219.8, P = 0.009), total melanonychia (odds ratio = 17.6, confidence interval = 3.0-104.0, P = 0.002), nail plate destruction (odds ratio = 10.9, confidence interval = 2.0-59.4, P = 0.006) and polychromia (odds ratio = 5.3, confidence interval = 1.36-20.57, P = 0.016) were distinctive dermoscopic features of invasive nail unit melanoma. A predictive model with scores ranging from 0 to 6 points demonstrated a reliable diagnostic value (C-statistic = 0.902) in differentiating invasive nail unit melanoma from nail unit melanoma in situ.

CONCLUSIONS

Invasive nail unit melanoma and nail unit melanoma in situ have different dermoscopic features. A predictive model based on morphologic dermoscopic features could aid in differentiating invasive nail unit melanoma from nail unit melanoma in situ.

Rhizolutin, a Novel 7/10/6-Tricyclic Dilactone, Dissociates Misfolded Protein Aggregates and Reduces Apoptosis/Inflammation Associated with Alzheimer's Disease

Rhizolutin (1) was discovered as a natural product of ginseng-rhizospheric Streptomyces sp. WON17. Its structure features an unprecedented 7/10/6-tricyclic dilactone carbon skeleton composed of dimethylcyclodecatriene flanked by a 7-membered and a 6-membered lactone ring based on spectroscopic analysis. During an unbiased screening of natural product libraries, this novel compound was found to dissociate amyloid-β (Aβ) plaques and tau tangles, which are key pathological hallmarks of Alzheimer's disease (AD). Rhizolutin treatment of APP/PS1 double transgenic mice with AD significantly dissociated hippocampal plaques. In vitro, rhizolutin substantially decreased Aβ-induced apoptosis and inflammation in neuronal and glial cells. Our findings introduce a unique chemical entity that targets Aβ and tau concurrently by mimicking misfolded protein clearance mechanisms of immunotherapy, which is prominently investigated in clinical trials.

Xenogenization of tumor cells by fusogenic exosomes in tumor microenvironment ignites and propagates antitumor immunity

Many cancer patients not responding to current immunotherapies fail to produce tumor-specific T cells for various reasons, such as a lack of recognition of cancer cells as foreign. Here, we suggest a previously unidentified method for xenogenizing (turning self to non-self) tumors by using fusogenic exosomes to introduce fusogenic viral antigens (VSV-G) onto the tumor cell surface. We found that xenogenized tumor cells were readily recognized and engulfed by dendritic cells; thereby, tumor antigens were efficiently presented to T lymphocytes. Moreover, exosome-VSV-G itself acts as a TLR4 agonist and stimulates the maturation of dendritic cells, leading to CD8⁺ T cell cross-priming. The administration of these exosomes in multiple tumor mouse models xenogenized tumor cells, resulting in tumor growth inhibition. The combinatorial treatment with anti-PD-L1 exhibited complete tumor regression (30%) and better long-term overall survival. These results suggest that tumor xenogenization by fusogenic exosomes provides a previously unidentified novel strategy for cancer immunotherapy.

OP0202 STRESS-ACTIVATED MIR-204 GOVERNS SENESCENT PHENOTYPES OF CHONDROCYTES TO PROMOTE OSTEOARTHRITIS DEVELOPMENT

Background:

A progressive loss of cartilage matrix leads to the development of osteoarthritis (OA). Matrix homeostasis is disturbed in OA cartilage as the result of reduced production of cartilage-specific matrix and increased secretion of catabolic mediators by chondrocytes. Chondrocyte senescence is a crucial cellular event contributing to such imbalance in matrix metabolism during OA development.

Objectives:

We sought to identify a previously unknown, senescence-associated signaling pathway in chondrocytes linked to major OA cartilage manifestations such as PG loss and cartilage degeneration.

Methods:

We particularly aimed to screen miRNAs whose inhibition could effectively modulate senescent phenotypes of chondrocytes to treat OA. We investigated the regulatory mechanisms of miR-204 under various stress-eliciting stimuli in primary cultured human and mouse chondrocytes. We examined the in vivo effects of miR-204 overexpression and its antagonism in surgically induced OA mouse models. DMM surgery was used to induce posttraumatic OA in 12-week-old mice. Small RNAs were delivered to mouse knee joints by intra-articular injection. Various OA manifestations including cartilage destruction, subchondral bone sclerosis, osteophyte maturity, and synovial inflammation in mice were histologically inspected.

Results:

We identify miR-204 as a senescence-associated microRNA (miRNA) which is markedly upregulated in OA cartilage. The upregulated miR-204 simultaneously targets multiple components of the sulfated proteoglycan (PG) biosynthesis pathway, effectively shutting down PG anabolism. Ectopic expression of the miR-204 in joints triggers spontaneous cartilage loss and OA development, whereas inhibition of miR-204 ameliorates experimental OA, with concomitant recovery of PG synthesis and suppression of inflammatory senescence-associated secretory phenotype (SASP) factors in cartilage

Conclusion:

we unravel a stress-activated senescence pathway that underlies disrupted matrix homeostasis in OA cartilage.

References:

[1]O. H. Jeon, C. Kim, R.-M. Laberge, M. Demaria, S. Rathod, A. P. Vasserot, J. W. Chung, D. H. Kim, Y. Poon, N. David, D. J. Baker, J. M. van Deursen, J. Campisi, J. H. Elisseeff, Local clearance of senescent cells attenuates the development of post-traumatic osteoarthritis and creates a pro-regenerative environment. Nat. Med. 23, 775–781 (2017)

Disclosure of Interests:

None declared

AB0080 A SYSTEM-LEVEL APPROACH IDENTIFIES A CRITICAL REGULATOR OF CHONDROSARCOMA PROGRESSION

Background:

Chondrosarcomas are cartilaginous tumors that constitute one-third of skeletal system cancers. Chondrosarcomas are capable of transitioning to highly metastatic and treatment-refractory states, resulting in significant patient mortality. However, the molecular events accompanying this behavior remain unknown.

Objectives:

We aimed to uncover the molecular pathway underlying such tumor progression that confers a higher malignancy to chondrosarcoma.

Methods:

We conducted unsupervised gene co-expression network analyses using transcriptomes of patients with chondrosarcoma and extracted a characteristic transcription network underlying chondrosarcoma malignancy. By implementing a system-level upstream analysis of this gene network, we identified the transcriptional factor as a key regulator governing chondrosarcoma progression. We unraveled the functional roles of the identified factor in promoting tumor growth and metastasis of chondrosarcomas in the context of their unique microenvironments.

Results:

By conducting system-level upstream analysis, we identified a factor as a transcriptional regulator that governs the malignancy gene module. The identified factor was upregulated in chondrosarcoma biopsies associated with a high histological grade and conferred chondrosarcoma cells invasiveness and tumor-initiating capacity. In an orthotopic xenograft mouse model, the identified factor modulated local outgrowth and pulmonary metastasis of chondrosarcoma. Pharmacological inhibition of the identified factor in conjunction with the chemotherapy agents such as cisplatin or doxorubicin synergistically enhanced chondrosarcoma cell apoptosis and abolished malignant phenotypes of chondrosarcoma in mice.

Conclusion:

Our study provides a proof of concept evidence that inhibiting the identified factor suppresses progression of chondrosarcoma and improves the efficacy of chemotherapy in cellular and pre-clinical levels. Taken together, we believe that our findings provide novel molecular insights for the development of new anti-cancer therapies to target chondrosarcomas.

References:

[1]Gelderblom H, et al. The clinical approach towards chondrosarcoma. Oncologist 13, 320-329 (2008)

Disclosure of Interests:

None declared

0622 In-Depth Surveillance of Central Sleep Apnea in Patients with Stable Heart Failure

Introduction

Central sleep apnea (CSA) is unique sleep breathing phenotype in patients with advanced chronic heart failure (HF) and portend poor prognosis. The prevalence of CSA in HF patients under contemporary therapy is uncertain.

Methods

We reviewed consecutive HF patients on optimal medical therapy who underwent clinically indicated diagnostic in-lab polysomnography at a single academic center. Age, sex and BMI matched patients without HF were selected from sleep clinic as a control. Patients with atrial fibrillation were excluded from this study. Apnea subtypes were determined after careful scoring and confirmation by sleep physicians. ‘Any CSA’ was defined by central apnea index (CAI) >5 and >1/hr. ‘True CSA’ was defined if met both CAI≥5/hr and > obstructive apnea index (OAI). Obstructive sleep apnea (OSA) was defined if apnea hypopnea index >15 and OAI>CAI. Multivariate analysis was performed using logistic regression adjusting for age, sex, HF and systolic dysfunction as appropriate.

Results

In patients with HF (N=95, mean age 59, female: 50%), CSA was low and was comparable to control group (N=94) (HF vs. Non-HF; CSA: 5.3 vs. 4.3%, P=NS; Any CSA 14.7 vs. 17%, P=NS). Only 3 patients with HF had true CSA. In contrast, OSA was common in both groups regardless of obesity status (52.3 vs. 55.3%). In patients with HF, Cheyne Stokes respiration was more frequent in patients with Any CSA vs. without Any CSA (13.3 vs. 3.8%, p=0.04). In multivariate analysis, presence of OSA, but not HF, was associated with Any CSA in entire cohort (Any CSA OR: 3.1 [1.3, 8.1], p=0.02). In patients with HF, male sex was associated with Any CSA (OR: 5.3 [1.1, 40.8], p=0.05). Exclusion of patients with high BMI did not change the results.

Conclusion

CSA was rare in patients with stable HF on contemporary optimal medical therapy.

Support

None

1052 Continuous Blood Pressure Monitoring In Sleep

Introduction

Abnormal nocturnal blood pressure(BP) such as non-dipping or nocturnal hypertension(reverse-dipping) represents a potent marker for cardiovascular risks. Standard cuff-based ambulatory nocturnal BP measurement yields limited data points potentially resulting in imprecise results, especially compared to continuously recorded BP. We hypothesized nocturnal BP based on periodic measurement would be different from true average beat-to-beat based BP.

Methods

We prospectively enrolled patients undergoing clinically indicated in-lab polysomnography, both CPAP and non-CPAP studies, for sleep apnea evaluation. Nocturnal BP was continuously monitored beat-to-beat by a noninvasive Caretaker™ device, which uses the Pulse Decomposition Analysis(PDA) algorithm. We compared BP recorded at 30-minute intervals with average BP continuously recorded over 30 minutes, both recorded by Caretaker™. We also looked at the differences between recording spot and continuous BP from an awake or sleeping state and BP variability(SD) based on continuously recorded BP. Using first 30 min as a reference, we determined dipping status (dipping: 10-20% reduction, level: 0-10% reduction, riser: any increase) by the two methods.

Results

A total of 18 patients were recruited(male:11, mean age:52.2). Among a total of 261 periodic BP measurements, 60 (30.0%) were obtained while awake. Mean nocturnal SBP by periodic BP measurement was higher compared with beat-to-beat-derived average BP(135.6mmHg[24.2] vs. 131.5[20.3], p<0.0001). The difference between the two methods remained similar when continuous BP was derived from sleep vs. awake period(4.5mmHg[3.1] vs. 7.7[9.9], p=0.202). BP variability was more pronounced during awake compared with sleep period(6.7mmHg[8.1] versus 3.95[7.5], p=0.047). 8 patients were dippers by spot check measurement, but 11 were dippers by continuous BP.

Conclusion

Standard ambulatory periodic nocturnal BP recording may not yield true sleep BP patterns due to its spot-check nature and lack of sleep-awake information, which leads to inaccurate dipping measurements. Incorporation of beat-to-beat continuous BP measurement can provide more accurate and meaningful nocturnal BP information.

Support

N/A

0791 Effects of Low Frequency Electrical Stimulators as Nonpharmacological Treatment in Restless Legs Syndrome

Introduction

Non-pharmacological treatments for restless legs syndrome (RLS) is a treatment option for patients who have not yet started medical treatment, who do not respond to their prescribed medication, or who suffer from adverse effects of medication. This study aims to investigate the clinical effectiveness of low frequency electronic stimulators (LFES) as a non-pharmacological treatment.

Methods

This is a randomized, single-blind study. After screening 64 patients according to the inclusion/exclusion criteria, a total of 46 patients participated in the study. The participants were separated into an active group and a sham group with 22 and 24 members, respectively. The stimulation was administered using the tapping mode (3Hz) present on the machines used, and symptom changes were measured in both groups. The effects of the stimuli were analyzed with repeated measures ANOVA.

Results

Symptom severity was significantly reduced in the active group, and showed significant interaction effects in the time multiple group. Although both the active and sham groups reported improved symptoms upon receiving longer periods of treatment, the effect of the LFES was greater in the active group.

Conclusion

Analyzing the effects of LFES by dividing the active and sham groups revealed that LFES treatment resulted in symptom improvement when using effective stimulation intensity. LFES can be a non-pharmacological treatment option for RLS.

Support

None

Bilateral inferior renal polar arteries with a high origin from the abdominal aorta

Bilateral multiple renal arteries are not-so-rare variations. However, inferior renal polar arteries with a high origin from the abdominal aorta have rarely been reported. We found bilateral inferior renal polar arteries with a high origin from the abdominal aorta in an 84-year-old Korean female cadaver. Two right and three left renal arteries were seen with the lowest as the main renal artery bilaterally. The highest artery crossed the main renal artery and penetrated into the inferior pole of the kidney, respectively. After dissection, each inferior polar artery could be classified as the inferior segmental branch. A further understanding on its embryogenesis might be important since variations in renal arteries are of particular interest to clinicians as well as anatomists.

An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

PIN1 Attenuation Improves Midface Hypoplasia in a Mouse Model of Apert Syndrome

Premature fusion of the cranial suture and midface hypoplasia are common features of syndromic craniosynostosis caused by mutations in the FGFR2 gene. The only treatment for this condition involves a series of risky surgical procedures designed to correct defects in the craniofacial bones, which must be performed until brain growth has been completed. Several pharmacologic interventions directed at FGFR2 downstream signaling have been tested as potential treatments for premature coronal suture fusion in a mouse model of Apert syndrome. However, there are no published studies that have targeted for the pharmacologic treatment of midface hypoplasia. We used Fgfr2^S252W/+ knock-in mice as a model of Apert syndrome and morphometric analyses to identify causal hypoplastic sites in the midface region. Three-dimensional geometric and linear analyses of Fgfr2^S252W/+ mice at postnatal day 0 demonstrated distinct morphologic variance. The premature fusion of anterior facial bones, such as the maxilla, nasal, and frontal bones, rather than the cranium or cranial base, is the main contributing factor toward the anterior-posterior skull length shortening. The cranial base of the mouse model had a noticeable downward slant around the intersphenoid synchondrosis, which is related to distortion of the airway. Within a skull, the facial shape variance was highly correlated with the cranial base angle change along Fgfr2 S252W mutation-induced craniofacial anomalies. The inhibition of an FGFR2 downstream signaling enzyme, PIN1, via genetic knockdown or use of a PIN1 inhibitor, juglone, attenuated the aforementioned deformities in a mouse model of Apert syndrome. Overall, these results indicate that FGFR2 signaling is a key contributor toward abnormal anterior-posterior dimensional growth in the midface region. Our study suggests a novel therapeutic option for the prevention of craniofacial malformations induced by mutations in the FGFR2 gene.

P3617Systolic blood pressure, glycemic control and clinical outcome in diabetic patients with acute myocardial infarction

Background

Recent blood pressure guidelines recommend intensive blood pressure control in diabetic patients with cardiovascular disease.

Purpose

We sought to investigate combined impact of intensive blood glucose lowering and blood pressure control on clinical outcome in diabetic patients with acute myocardial infarction (AMI) has not been fully investigated yet.

Method

Korean Acute Myocardial Infarction Registry (KAMIR) – National Institute of Health (NIH) database included 12,179 patients (9,046 men; mean age = 63.6±12.6 year-old) who were discharged alive. Among them, 3,430 (28.2%) had a diabetes mellitus (DM). MACCEs were defined as a composition of all cause death, non-fatal MI, repeat revascularizations including repeated percutaneous coronary intervention and coronary bypass grafting, cerebrovascular accident and rehospitalizations at 1 year. This research was supported by a fund by Research of Korea Centers for Disease Control and Prevention.

Result

We determined cut-off value of discharge systolic blood pressure (SBP) to predict 1-year MACCE in DM and non-DM patients. Discharge SBP of less than 130mmHg was associated with a lower MACCE at 1 year compared to SBP level of 130mmHg or greater (10.8% versus 15.4%; log-rank p=0.001) in DM patients, whereas discharge SBP cut-off level was 140mmHg to discriminate 1-year MACCE in non-DM patients (6.4% versus 8.5%, log-rank p=0.045). In DM patients, there were no significant difference in 1-year MACCEs between patients with HbA1c less than 7% versus 7% or greater (12.0% versus 10.7%; log-rank p=0.325). DM patients were categorized into 4 groups; discharge SBP <130mmHg and HbA1c <7% (Group 1); discharge SBP <130mmHg and HbA1c ≥7% (Group 2); discharge SBP ≥130mmHg and HbA1c <7% (Group 3); discharge SBP ≥130mmHg and HbA1c ≥7% (Group 4). Intensive BP control was associated lower 1-year MACCEs in patients with good glycemic control (Group 1 & 3; 10.7% versus 16.7%; log-rank p=0.009). However, in patients with poor glycemic control, intensive BP control did not improve 1-year MACCEs (Group 2 & 4; 10.6% versus 11.1%; log-rank p=0.761).

Conclusion

Strict BP control is more important than glycemic control to improve short-term clinical outcome in DM patients with AMI. However, in patients with poor glycemic control, strict BP control did not improve clinical outcome.

P3583Optimal procedural strategy to improve clinical outcome in primary percutaneous coronary intervention

Background

Current guideline recommends potent antiplatelet agents and transradial intervention. However, it is uncertain whether routine use of IVUS, thrombus aspiration and glycoprotein IIB-IIIA inhibitor is beneficial for improving clinical outcome in patients with ST-segment elevation myocardial infarction (STEMI).

Purpose

The aim of this study was to investigate optimal procedural strategy to improve clinical outcome.

Methods

A total of 6,046 patients who underwent primary percutaneous coronary intervention (PCI) for STEMI were analyzed from the Korean Acute Myocardial Infarction Registry (KAMIR) – National Institute of Health (NIH) database. MACCEs were defined as a composition of all cause death, non-fatal MI, repeat revascularizations including repeated percutaneous coronary intervention and coronary bypass grafting, cerebrovascular accident and rehospitalizations. This research was supported by a fund by Research of Korea Centers for Disease Control and Prevention.

Results

During the primary PCI, potent antiplatelet agents such as prasugrel and ticagrelor were used in 2342 (38.4%). PCI was performed through transradial approach in 1490 (25.2%). Thrombus aspiration and intravascular ultrasound (IVUS) examination was done in 2204 (36.1%) and 1079 (18.1%), respectively. Glycoprotein IIB-IIIA inhibitor was administered in 1295 (21.7%). Among them, potent antiplatelet agents, transradial intervention, IVUS, and thrombus aspiration significantly reduced MACCEs at 1 year. Glycoprotein IIB-IIIA inhibitor was not effective to improved clinical outcome. In Cox-proportional hazards model, potent antiplatelet agents (hazard ratio 0.82, 95% confidence interval 0.67–0.99; p=0.045) and transradial intervention (hazard ratio 0.61, 95% confidence interval 0.47–0.78; p<0.001) was an independent predictor of MACCEs after adjusting for confounding variables. Combined use of potent antiplatelet agents and transradial intervention (hazard ratio 0.54; 95% confidence interval 0.37–0.80; p=0.002) substantially reduced MACCEs at 1 year.

Conclusion

Among evidence based procedures during the primary PCI, combined use of potent antiplatelet agents and transradial intervention was optimal procedural strategy to improve clinical outcome.